Human Anatomy & Physiology
Syllabus
(As per ER-2020)
Human Anatomy and Physiology
Scope of anatomy and physiology: Definition of various terms used in anatomy.
Structure of cell: Function of its components with special reference to mitochondria and microsomes.
Tissues of the human body: Epithelial, connective, muscular and nervous tissues, their sub-types and characteristics.
a. Osseous system: Structure and functions of bones of axial and appendicular skeleton.
b. Classification, types and movements of joints, disorders of joints.
Haemopoietic system: Composition and functions of blood, process of haemopoiesis, characteristics and functions of RBCs, WBCs and platelets, mechanism of blood clotting, importance of blood groups.
Lymphatic system: Lymph and lymphatic system, composition, function and its formation, structure and functions of spleen and lymph node.
Cardiovascular system: Anatomy and physiology of heart, blood vessels and circulation (pulmonary, coronary and systemic circulation), cardiac cycle, heart sounds, basic knowledge of ECG, blood pressure and its regulation.
Respiratory system: Anatomy of respiratory organs and their functions, regulation and mechanism of respiration, respiratory volumes and capacities—definitions.
Digestive system: Anatomy and physiology of GIT, anatomy and functions of accessary glands, physiology of digestion and absorption.
Skeletal muscles: Histology, physiology of muscle contraction, disorders of skeletal muscles.
viii Human Anatomy and Physiology
Nervous system: Classification of nervous system, anatomy and physiology of cerebrum, cerebellum, mid-brain, functions of hypothalamus, medulla oblongata, and basal ganglia, spinal cord-structure and reflexes, names and functions of cranial nerves, anatomy and physiology of sympathetic and parasympathetic nervous system (ANS).
Sense organs: Anatomy and physiology of eye, ear, skin, tongue and nose.
Urinary system: Anatomy and physiology of urinary system, physiology of urine formation, renin-angiotensin system, clearance tests and micturition.
Endocrine system (hormones and their functions): Pituitary gland, adrenal gland, thyroid and parathyroid gland, pancreas and gonads.
Reproductive system: Anatomy of male and female reproductive system, physiology of menstruation, spermatogenesis and oogenesis, pregnancy and parturition.
Preface to the Fourth Edition v
Introduction and Scope of Anatomy and 1
Physiology
The Cell 3
The Tissue of the Human Body 9
The Osseous System (The Skeleton) 17
The Haemopoietic System 27
The Lymphatic System 40
The Cardiovascular System 45
The Respiratory System 64
The Digestive System 72
The Skeletal Muscles 84
The Nervous System 89
The Sense Organs 99
The Urinary System 121
The Endocrine System 134
The Reproductive System 141
Appendix
Objective Questions with Answers 155
Introduction and Scope of Anatomy and Physiology
1 Give the scope/importance of anatomy and physiology.
Scope of Anatomy and Physiology:
Anatomy is the study of structure and physiology is the study of functions of body parts.
This subject is designed to impart fundamental knowledge of the structure and functions of the various systems of the human body.
This subject helps to understand homeostatic mechanisms.
This subject provides the basic knowledge required to understand the various disciplines in pharmacy.
The knowledge of anatomy and physiology is useful for understanding pathology of disease and pathological changes.
2 Define the terms.
1. Anatomy: It is the study of different parts of the body, their forms, position and relationship with each other.
Physiology: It is the study of function of the body as a whole and functions of individual structures and systems present in the body.
Cell: Cell is the smallest, basic, living, structural and functional unit of the body.
Tissue: A group of cells having similar physical characters performing same specialized function.
Anatomical position: This is the upright position of the body with the head facing forwards, the arms at
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2 Human Anatomy and Physiology
the sides with palms of the hands facing forward and the feet together.
Proximal end: It means the part of the structure nearest to a given point.
Distal end: It means the part of the structure away from a given point.
Median/medial/axial: The structure situated actually on the axis is known as median.
Longitudinal: A line along or parallel to the axis is known as longitudinal.
Lateral: It means the position present at the side of the axis.
Transverse: A line across at a right angle to the axis is a transverse.
Superior: It is the upper end of the body.
Inferior: It is the lower end of the body.
Ventral/anterior: It is the aspect of the body which faces viewer.
Dorsal/posterior: It is the surface of the body at back side.
Fossa: It is a depression or a hollow.
Meatus: It is a tube-shaped cavity within a bone.
Foramen: It is a hole in the structure.
Sinus: It is a hollow cavity within a bone.
Facet: It is a small, flat articulating surface.
Condyle: It is a smooth rounded projection of bone which takes part in joint.
Septum: It is a partition separating two cavities.
Fissure or cleft: It indicates narrow slit.
Sutures: These are fixed joints between bones of skull and cranium.
Articulation: It is a joint between two or more bones.
The Cell
1 Define cell. Enlist different components/parts of cell.
OR Enlist different cellular components.
Cell
The cell is the smallest, basic, living, structural and functional unit of the body.
Different Components/Parts of Cell
Major intracellular organs/organelles are as follows.
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2 Sketch and label a diagram of cell.
Diagram of Cell
Cell
3 Write a short note on 1. Nucleus, 2. Endoplasmic reticulum, 3. Golgi complex, 4. Mitochondria,
5. Lysosomes, 6. Cell wall.
1. Nucleus
It is a spherical and largest part of the cell. It contains nuclear membrane, nucleoplasm, nucleoli and genetic material DNA. Nuclear membrane is continuous with endoplasmic reticulum.
Functions
It controls all cellular activities.
It contains DNA, RNA and proteins.
RNA helps in protein synthesis.
DNA helps in production of chromosomes.
Endoplasmic Reticulum (ER)
It is a network of membrane continuous with cell membrane and nuclear membrane. It is of two types.
Rough-surfaced ER: Ribosomes are present at the outer border of the membrane.
Smooth-surfaced ER: Smooth-surfaced ER does not possess ribosomes at the outer border of the membrane.
Functions
It provides a surface area for a number of chemical reactions.
It helps in synthesis of steroids, proteins, etc.
It provides a pathway for transporting various chemical substances.
It helps to concentrate the products of synthetic activities of the cell.
Golgi Complex/Golgi Apparatus
It consists of 4 to 8 flattened bag-like channels stacked upon each other with expanded areas at the ends. The structure looks like a network of fine threads or irregular granular material hence called Golgi complex. It is located near the nucleus.
Functions
It helps in packaging of secretory proteins.
It helps in synthesis of carbohydrates.
It helps in intracellular sorting of proteins.
Mitochondria
Mitochondria are small intracellular organelles and are also known as power house of cell or store house of energy.
It is bound by inner folded and outer smooth-surfaced membrane. Inner membrane has many cristae and is covered with F1 particles.
Functions
Mitochondria
It is the main site of synthesis and storage of ATP.
It is the site for citric acid cycle, -oxidation and urea cycle, ETS, etc.
It contains special DNA and is self-replicative.
It performs the main function of conversion and transfer of cellular energy.
Physiology of Mitochondria
When nutrients and oxygen come in contact with oxidative enzymes present in the mitochondria, they combine to form CO2, water and liberated energy is utilised to synthesize ATP. The ATP then diffuses throughout the cells and releases its stored energy for performing cellular functions.
Lysosomes (Digestive Apparatus of Cell/Suicide Packets)
Lysosomes are described as a separate cytoplasmic organelles. These are membranous vesicles containing powerful digestive enzymes which are capable of breaking down many kinds of molecules.
Functions
It helps in intracellular digestion.
Autolysis
Phagocytosis
Systematic growth and death can be managed by lysosomal activity.
Cell Membrane/Cytoplasmic Membrane/Plasma Membrane/ Cell Wall
It is a membrane which covers and protects the cell and surrounds the cytoplasm. It separates the cells from each other and external environment.
The cell wall is composed of proteins, phospholipids, carbohydrates, minerals, etc.
Functions
It covers and protects the cell and organelles.
It gives shape to the cell.
It is involved in the transport of molecules in and out of the cells.
It forms channels of endoplasmic reticulum (ER).
It forms boundaries to the cytoplasm.
It can act as a physiological sieve (semipermeable membrane).
It helps in intracellular adhesion and communication.
4 Explain physiology of cell wall.
Physiology of Cell Wall
The cell wall forms the boundary of the cell, inside which various organelles and protoplasm are present. The cell wall is mainly composed of proteins, carbohydrates, phospholipids, minerals, etc. The cell wall is a semipermeable membrane which acts as a sieve through which certain substances are allowed to enter the cell while some other substances are allowed to move outside the cell in the form of excreta.
The substances pass through semipermeable membrane and it depends upon their:
Particle size
Concentration
Lipid solubility
Electrical charges
Presence of carrier molecules.
5 Why lysosomes are known as ‘suicide bags’/suicide packets/digestive apparatus of the cell?
• Lysosomes are membranous vesicles containing powerful digestive enzymes which are capable of breakdown of many kinds of molecules.
Lysosomes are known as suicide bags of cell because they contain lytic enzymes capable of digesting cells and unwanted materials when lysosomes brust, the lytic enzymes within it spill all over the cell, rupturing the cell membrane or cell wall and inducing the death of cell. This is also known as autolysis.
6 Why mitochondria are called powerhouse/storehouse of cell (energy coin/storehouse of energy)?
• Mitochondria are tiny organelles present inside the cell.
They are involved in release of energy from food. This is known as cellular respiration.
They generate energy rich molecules ATP from cellular respiration which are later used for other processes.
The energy is stored in the form of ATP.
It is the main site for citric acid cycle, -oxidation, urea cycle, ETS, etc. where, ATP is generated.
Hence, mitochondria are called the powerhouse of the cell.
7 What are various stages of cell reproduction or cell division?
Stages of Cell Reproduction
Prophase
Metaphase
Anaphase
Telophase
The Tissue of the Human Body
1 Define tissue. Classify various fundamental tissues of the body.
Tissue
The group of cells having similar physical characters and performing same specialized function, is known as tissue.
Fundamental/Basic Principle/Tissues of the Human Body or Classification/Types of Tissues
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2 Give the properties and functions of epithelial tissues.
Epithelial Tissues
These types of tissues give covering to the body organs and various cavities including mainly digestive passages and respiratory system.
Properties of Epithelial Tissue
It consists of large closely packed cells with extracellular material between adjacent cells.
Cells are arranged in continuous sheet in either single or multiple layers.
Epithelial cells have free surface exposed to body cavity and basal surface attached to the basement membrane.
Epithelial cells have a nerve supply.
They have high regeneration capacity.
Functions of Epithelial Tissue
It covers and protects underlying tissues against injury.
It helps in secretion of special chemical substances.
It also helps in absorption and distribution of different substances and drugs.
Outside the body, epithelial tissue forms skin and inside the body it forms membrane and glands.
3 Classify muscular tissues. Mention the functions of muscular tissue.
Muscular Tissue
Muscular tissues contain muscle fibres which generate force of contraction.
Muscular tissue is composed of water (75%), proteins (20%), mineral salts, glycogen, fat, glucose, etc. (5%).
Classification/Types/Kinds of Muscular Tissues
Functions of Muscular Tissue
It gives shape to the organs and body.
It forms walls of the body cavities and gives support to the organ.
It gives locomotion to the body.
It maintains body temperature by production of heat.
It maintains fluid balance of the body.
It helps to protect blood vessels and nerves.
It helps in the process of respiration, e.g. intercostal muscles and diaphragm are main respiratory muscles.
The cardiac muscles present in the myocardium of heart help in rhythmic contraction and relaxation.
Muscular tissue maintains posture (position) of the body.
4 Classify connective tissues.
Connective Tissues
These tissues bind together and support more active delicate tissues of the body.
These contain white fibres and yellow elastic fibres.
Classification/Types of Connective Tissues
5 Define bone. Mention functions of bone.
Bone
Definition
Bone is the hardest connective tissue in the body which provides a framework (skeleton) and gives mechanical support and shape to the body.
Functions of Bone
It forms supporting framework (skeleton) of the body.
It gives mechanical support and shape to the body.
It provides a store for minerals like calcium and phosphorus.
It maintains electrolytes balance of the body.
The bones also serve as detoxicating function (removal of toxic substances).
It helps in the formation of RBCs in the red bone marrow,
i.e. (haemopoietic function).
Bones give attachment to the muscles and tendons.
It gives movement to the body as a whole and parts of the body by forming joints.
Bones support and protect soft tissues and vital organs of the body.
It forms boundaries for cranial, thoracic and pelvic cavity.
6 What is cartilage? Give location, types and functions of cartilages.
Cartilage
Definition
Cartilage is a flexible connective tissue found mainly in connection with skeleton and provides support with flexibility.
Location
It is found:
At the tip of the nose
In part of trachea (C-shaped rings)
In part of larynx
In between vertebrae (intervertebral discs)
In the pinna of ear.
Types of Cartilages
Hyaline cartilage
White fibrocartilage
Yellow elastic fibrocartilage.
Functions of Cartilages
It gives shape and support with certain amount of elasticity.
Fibrous cartilages act as a strong, flexible, connecting substance between the bones.
Cartilages present in the joint prevent friction between the bones during movements.
The C-shaped cartilages present in the trachea help to keep the tracheal tube always in open condition.
The cartilages present in between bodies of vertebrae prevent friction between them and allow very slight movement.
7 Define neuron. Draw and label a diagram of myelinated neuron.
Nervous Tissue
It is a highly specialized tissue which helps in transmission of impulses in the body.
Neurons are the basic structural and functional units of nervous tissue which help to transmit the impulses throughout the body.
Types/Classification of neurons/nerves
A. On the basis of myelin sheath B. On the basis of function
Myelinated neuron
Non-myelinated neuron
Sensory neuron/nerve
Motor neuron/nerve
Mixed neuron/nerve
Structure
8 Describe various parts of neuron.
Description of Neuron
Each neuron consists of (a) nerve cell, (b) dendrites, (c) axon.
Nerve Cell
It form gray matter of nervous system. The nerve cells in group are called ganglia.
Functions
It stimulates impulses.
It helps in generation and transmission of impulses.
Dendrites
The branches of the nerve cell are called dendrites.
Function
They receive the impulses from synapse towards the nerve cell.
Axon
The elongated main fibre originated from the nerve cell is called axon. It forms white matter of the nervous system.
Axolemma: It is a membrane which covers and protects axon and contains axoplasm.
Myelin sheath: It is a sheath of fatty material which surrounds axon. The points where myelin sheath is absent are known as nodes of Ranvier.
Functions of Myelin Sheath
It protects the axon from injury.
It contributes to rapid transmission of nerve impulses along myelinated fibres.
It acts as an insulator.
It speeds up the flow of nerve impulses through them.
9 Enlist types of neurons on the basis of functions.
Types of Neurons/Nerves on the Basis of Function
Sensory Neurons or Afferent Neurons
These neurons transmit the impulses from different parts of the body to the spinal cord and then to the brain where they are interpreted and sensed, e.g. sense of taste, sight, touch.
Motor Neurons or Efferent Neurons
These neurons convey the impulses from brain and spinal cord towards various parts of the body, e.g. stimulating glandular secretions and causing muscles contraction.
Mixed Neurons/Intercalated Neurons
When sensory and motor neurons are enclosed within the same sheath of connective tissue they are called mixed neurons. They perform both sensory and motor functions.
10 Define the terms.
Important Definitions
Cytology: The branch of science which deals with study of cells is known as cytology.
Synapse: The gap between two neurons where transmission of impulses takes place, is called synapse.
Chemical transmitter/neurotransmitter: The chemical substances which are secreted by nerve cell in the synaptic gap, are called neurotransmitters.
Intracellular fluid: The fluid which is present inside the cell, is known as intracellular fluid, e.g. cytoplasm.
Extracellular fluid: The fluid which is present outside the cell, is known as extracellular fluid.
Plasma fluid: The fluid which is present in the blood plasma and lymph, is known as plasma fluid, e.g. blood plasma, lymph.
Transcellular fluid: The fluid which is present in different layers and membranes of the body, is known as transcellular fluid, e.g. CSF, synovial fluid, serous fluid.
The Osseous System
(The Skeleton)
1 Define skeleton. Give the functions of skeleton.
Skeleton
“The bony framework of the body, which supports and protects the soft tissues of the body and provides levers for locomotion and other movements, is called skeleton.”
Functions
It gives a definite shape to the body.
It provides support to different internal parts of the body like brain, heart, lungs, etc.
It serves as a storehouse of calcium and phosphate.
It provides surface for the attachment for skeletal muscles.
It transmits body weight.
It gives a rigid internal structural framework to the body.
The long bones of skeleton help in formation of RBCs.
It gives protection to viscera.
It allows various types of movements of various body parts by forming joints or lever.
2 Define bone. Mention the functions of bone.
Bone
“Bone is the hardest connective tissue in the body which provides framework of the body and gives mechanical support and shape to the body.”
It gives shape and mechanical support to the body.
It acts as a storehouse for calcium and phosphate.
It forms supporting framework of the body (skeleton).
It gives movement to body by forming various joints.
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It maintains electrolyte balance of the body.
The bones also perform detoxicating function.
The bone performs haemopoietic function (formation of RBCs).
It gives attachment to the muscles and tendons.
3 Classify bones/give the types/kinds of bones according to size and shape.
(a) Long bones: These are found in the limbs and consist of elongated shaft with two extremities.
Example: The bones of arm and leg, humerus, radius, ulna, femur, etc.
Short bones: They have no shaft but consist of smaller masses of spongy bone surrounded by a shell of compact bone.
Example: Carpals, tarsals.
Irregular bones: In this type, bones do not have a definite shape.
Example: Vertebrae, bones of the face.
Flat bones: It consists of two layers of compact bone between which there is a layer of cancellous bone.
Example: Scapula, innominate bone, bones of skull.
Sesamoid bone: These are small bones which are developed in the tendons around the certain joints.
Example: Patella or knee-cap: Patella is a roughly triangular sesamoid bone associated with the knee joint, i.e. it is present in front of the joint formed by femur and tibia bones (knee joint).
4 Define axial skeleton. Name the bones of axial skeleton.
Definition
The part of skeleton present along the axis is known as axial skeleton.
5 Define appendicular skeleton. Name the bones of appendicular skeleton.
Definition
The bones which are situated at the side of the axis are known as bones of appendicular skeleton.
6 Define vertebral column. Classify vertebrae. Give the functions of vertebral column.
Vertebral Column
It is a long, flexible curved bony rod, made up of irregular bones called vertebrae.
Types of Vertebrae
Cervical vertebrae (7)
Thoracic vertebrae (12)
Lumbar vertebrae (5)
Sacral vertebrae (5 fused)
Coccyx (4 fused).
Functions of Vertebral Column
It provides a strong bony protection for the delicate spinal cord.
It supports the skull.
It forms axis of the body.
It gives attachment to ribs, pelvic girdle, muscles of the back.
It provides necessary rigidity and flexibility to the body.
The intervertebral discs present between the bodies of vertebrae act as shock absorber.
7 Define joint/articulation. Explain various types of joint/ articulation.
Joint/Articulation
“The place where two or more bones join together is called a joint or articulation.”
Types of Joint/Classification of Joint
According to range of movement, the joints are classified as:
Explanation
Fixed/Immovable/Fibrous Joints
In this type of joint, there is no movement between the bones.
There is a fibrous tissue between the ends of the bones. Hence, it is called fixed joint, e.g.
Joints between bones of the skull.
Joints between the teeth and maxilla, mandible.
Slightly Movable/Cartilaginous Joints
In this type, there is a pad of cartilage between the articulating bones.
This allows for very slight movement caused by compression of the pad of cartilage, e.g. joints between the bodies of vertebrae.
Synovial Joint/Freely Movable Joints
The joints which allow free movements to the articulating bones, are called synovial joints/freely movable joints.
These joints are characterised by synovial membrane and synovial fluid.
Types of Synovial Joint
Ball and socket joint: In this type of joint, a globular head of one bone fits into a cup-shaped socket of another bone, which provides free movement, e.g.
Shoulder joint—between scapular and humerus.
Hip joint— between hip bone and femur.
Hinge joint: These joints allow the movements in one direction only, e.g.
Elbow joint—between humerus and radius, ulna.
Knee joint—between femur and tibia, fibula.
Double hinge joint: These allow the movements like a hinge but in two directions, e.g. joints between metacarpals and phalanges.
Gliding joint/plane joint: In this type, articulating surfaces of the bones glide/slide over each other allowing free movement in all directions, e.g. joints between carpals, joints between tarsals.
Pivot joint/axial joint: In this joint one bone turns on another and movement is around the axis, e.g. radioulnar joint, joints between femur and tibia.
Saddle joint: In this type, one bone is movable on another bone in many directions, e.g. thumb joint: It is the joint between metacarpal of the thumb with carpal of the wrist.
8 Explain typical synovial joint with the help of diagram.
A typical synovial joint
Characteristics of a Typical Synovial Joint
In this joint, there is a small cavity between articulating surfaces of the bones called synovial cavity.
The synovial cavity is filled with a thick, sticky fluid called synovial fluid.
The synovial fluid is surrounded by a membrane called synovial membrane.
The synovial fluid lubricates the joints and provides nutrition to living cells in the articulating cartilages which contain no blood vessels.
The articulating ends of both the bones are covered by hyaline cartilage.
The joint is enclosed in a fibrous capsule supported by ligaments.
Distinguish between the male and female pelvis/pelvic girdle.
Parts
Female pelvis
Male pelvis
(i)
Bones
Lighter and smaller
Heavier and longer
(ii)
Cavity
Shallow or round
Deep and funnel-shaped
(iii)
Sacrum
More concave anteriorly
Less concave anteriorly
(iv)
Pubic arch (angle)
The angle made by the two pubic bones at the symphysis pubis is wider.
The angle made by the two pubic bones at the symphysis pubis is narrower.
(v)
Girdle
Wider
Less wider
(vi)
Muscle attachment
Not so deeper
Deeper
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What are ribs? Classify them. Mention the functions of ribs.
Ribs
The ribs are long, curved bones which form thoracic cage.
There are 12 pairs of ribs in thoracic cage.
Types of Ribs
True ribs: The first 7 pairs of ribs which are directly joined to sternum in front and to the vertebral column behind, are called true ribs.
False ribs: The next 3 pairs of the ribs are joined to the 7th rib and not directly to the sternum, are called false ribs.
Floating ribs: The last 2 pairs of ribs which are joined to the vertebral column only, are known as floating ribs.
Functions of Ribs
Ribs form thoracic cage which protects delicate organs of the body.
Ribs support to the sternum and vertebral column.
Ribs help in the mechanism of respiration.
It gives shape to the chest.
It supports shoulder girdle.
11 What are sutures? Name the important sutures and their positions.
Sutures
Sutures are strong fibrous immovable joints between the bones of skull.
Frontal bone
Parietal bone
Occipital bone
Coronal suture
Sagittal suture Lambdoidal suture
Sutures
The important sutures are:
Coronal suture: The coronal suture is present between the frontal bone and the parietal bones.
Sagittal suture: The sagittal suture is present between two parietal bones.
Lambdoidal suture: The lambdoidal suture is present between occipital bone and the two parietal bones.
12 What are the sinuses of skull? Name two such sinuses.
Sinuses
The several cavities or chambers present in the bones of skull, are known as sinuses of skull.
Examples of Sinuses
Frontal sinuses
Ethmoid sinuses
Maxillary sinuses.
Functions of Sinuses
It lightens the weight of the skull.
It gives resonance to the voice.
13 Name the bones of upper limb with joints.
Bones of Upper Limb/Forearm
Scapula, humerus, radius, ulna, carpals, metacarpals, phalanges.
Joints of the Upper Limb
Ball and socket joint (shoulder joint): Between humerus and scapula.
Hinge joint: Between humerus and radius, ulna.
Pivot joint (radioulnar joint): Between radius and ulna.
Gliding joint: Between carpals.
Metacarpophalangeal joint: Between metacarpals and phalanges.
Interphalangeal joints: Between phalanges.
14 Name the bones of lower limb with joints.
Bones of Lower Limb/Hind Arm
Hip bone, femur, tibia, fibula, patella, tarsals, metatarsals, phalanges.
Joints of Upper Limb
Ball and socket joint (pelvic joint): Between hip and femur.
Knee joint: Between femur, tibia and fibula.
Pivot joint: Between tibia and fibula.
Gliding joint: Between tarsals.
Metatarsophalangeal joint: Between metatarsals and phalanges.
Interphalangeal joint: Between phalanges.
15 Explain disorders of bones and joint.
1. Arthritis: Inflammation of joint is called arthritis.
Acute arthritis
Chronic arthritis
Rheumatoid arthritis
Osteoarthritis
Gout: Gout is a condition where uric acid crystals are deposited in the joints and give pain in the joint.
Osteoporosis: When the bones have a deficiency of calcium and they become relatively more fragile, the condition is known as osteoporosis.
Fracture: When the bone is broken, the condition is called fracture.
Dislocation: When the bone is displaced from its original position, it is called dislocation of bone.
Sprain: Wrenching or twisting of a joint accompanied by stretching or tearing of ligament or tendons.
Ankylosis: This is a condition of immovability of a joint.
Synovitis: It is the inflammation of synovial membrane. The increased fluid in the joint may protrude out as swelling. During motions joint is having severe pain.
The Haemopoietic System
1 Define blood. Give the physical characteristics of the blood.
Blood
Blood is a red-coloured, viscous fluid connective tissue circulated in the body and is mainly composed of plasma and blood cells.
Physical Characteristics of Blood
Blood is a red-coloured, viscous fluid and is thicker than water.
Viscosity of blood is from 4.5 to 5.5.
The blood constitutes about 8% of the total body weight.
Temperature of blood is 38ºC.
Blood is slightly heavier than water.
Concentration of salt (NaCl) in the blood is about 0.85 to 0.9%.
The total amount of blood in the human body is about 5 to 5.5 litres.
pH of blood is 7.45 to 7.55.
2 Give the composition of blood.
Blood is composed of 45% of blood cells and 55% of plasma.
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3 Give the functions of blood.
Functions of Blood
Blood helps to transport the gases from lungs to the tissues (O2) and from tissues to the lungs (CO2).
Blood helps to transport the absorbed digested materials to the tissues of the body.
Blood acts as a vehicle through which many substances are transported to their places of activity.
Blood helps to drain out waste materials present in the body.
Blood acts as a great defensive mechanism.
Blood helps to regulate body temperatures.
Blood maintains acid–base balance of the body.
Blood has coagulation property due to which it prevents loss of blood from the body.
Blood helps to transport the hormones throughout the body.
Blood regulates body temperature.
4 Write a note on RBCs/erythrocytes.
• RBCs are small, circular, disc-shaped cells suspended in the blood plasma.
All the cells in groups, appear as red in colour and thus blood becomes red-coloured.
RBCs are produced in the red bone marrow. The process of formation of RBCs in the red bone marrow is called erythropoiesis.
Total lifespan of RBCs is 120 days.
The RBCs contain a substance known as haemoglobin and is enclosed in the stroma of RBCs.
Haemoglobin is a complex protein of high molecular weight.
Haemoglobin consists of a protein material called globin and non-protein material called ‘haem’.
The haem contains iron which gives red colour to the haemoglobin.
Normal values of RBCs:
In adult 5 million/mm3 of blood.
In male 5 to 5.5 million/mm3 of blood.
In female 4.5 to 5 million/mm3 of blood.
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Haemoglobin (Hb) + Oxygen (O ) Oxyhaemoglobin
(HbO2)
2
Haemoglobin (Hb) + Carbon dioxide (CO ) Carboxy-
haemoglobin (HbCO2).
Functions of RBCs/Erythrocytes
It transports the gases such as O2 and CO2 in the form of oxyhaemoglobin and carboxyhaemoglobin.
It maintains acid–base balance by buffering action of
haemoglobin.
RBCs help to maintain viscosity of blood.
RBCs maintain iron balance of the body.
Various pigments are derived from the haemoglobin after disintegration of RBCs, e.g. bilirubin, biliverdin.
5 Write a note on WBCs or leukocytes.
• The WBCs are colourless cells having, irregular-shaped large nucleus.
The normal count of leukocytes is 6000 to 10,000/mm3 of blood.
Classification of Leukocytes (WBCs)
Granulocytes
They constitute about 75%. These contain granules in the cytoplasm, hence called granulocytes.
Neutrophils: The granules of these cells are stained by neutral dye. The nucleus is multi-lobed.
Function: They ingest the microbes and destroy it by phagocytosis.
Basophils: The granules of these cells are stained by basic dye. The nucleus is usually oval or slightly kidney-shaped.
Function: They are responsible for destruction of
products of antigen–antibody reactions.
Eosinophils: The granules of these cells are stained by red acidic dye called eosin. The nucleus is bilobed.
Function: Phagocytosis.
Agranulocytes
These are mononuclear cells and they do not show presence of granules in their cytoplasm.
Monocytes: These are large cells with large nucleus. The nucleus is convoluted kidney-shaped.
Function: They give phagocytic action.
Lymphocytes: These are produced in the lymph glands hence called lymphocytes.
Small lymphocytes: The thin rim is present around nucleus and is stained by basic stains.
Large lymphocytes: The nucleus is oval, rounded or kidney-shaped and is stained by basic stains.
Function: They are responsible for the development of immunity against foreign substances such as microorganisms.
6 Mention the functions of leukocytes/WBCs.
Functions of WBCs/Leukocytes
WBCs help in the process of phagocytosis.
WBCs help in the formation of fibroblasts to repair the areas of inflammation.
WBCs give secretion of heparin which helps to prevent intravascular clotting (thrombosis).
WBCs prevent allergic reactions by antihistaminic action.
Lymphocytes play an important role in the production of antibodies.
7 Give the normal values of the following.
1. Erythrocytes (RBCs):
Average: 5 million/mm3 of blood
In male: 5 to 5.5 million/mm3 of blood
In female: 4.5 to 5 million/mm3 of blood.
Leukocytes (WBCs): 6,000 to 10,000/mm3 of blood.
Thrombocytes (platelets): 3 to 4 lacs/mm3 of blood.
Haemoglobin:
Average: 15 g/100 ml of blood.
In male: 14 to 18 g/100 ml of blood.
In female: 12 to 16 g/100 ml of blood.
8 Define the terms.
(i) Bleeding time: It is the time interval between moment at which the bleeding starts to the moment at which it exactly stops. Or
It is the time required for cessation of bleeding from a small skin puncture.
Normal value: 1 to 3 min (by Dukes method).
Clotting time/coagulation time: It is the time interval between the moment at which blood escapes from the vessel to the moment at which clot is formed.
Normal value: 3 to 6 min (by Wrights capillary method).
Blood serum: It is the fluid remaining after formation of clot.
9 Define blood coagulation. Explain stages of blood coagulation. Or What is blood clotting? Explain mechanism of blood clotting. Or Explain, how clot is formed?
Blood Coagulation
“When there is an injury to blood vessel, blood comes out and within a few minutes, it loses its fluidity and forms a red-coloured, semisolid jelly-like mass, i.e. clot. This process is known as blood coagulation or blood clotting.”
Mechanism of Blood Coagulation/Process of Blood Clotting
Step I
The injury to blood vessel leads to formation of a rough surface. The platelets when come in contact with rough surface, they are ruptured and thromboplastin is released. It is also released
by damaged tissues. This thromboplastin in the presence of calcium converts inactive prothrombin present in the blood into active thrombin.
Prothrombin + Thromboplastin + Ca2+ Thrombin
(inactive) (active)
Step II
The active thrombin converts inactive fibrinogen into insoluble fibrin threads which form a network-like structure.
Thrombin + Fibrinogen Fibrin threads
(active) (inactive) (insoluble)
Step III
In the holes of network of these fibrin threads, the blood cells get entangled to form a red-coloured semisolid jelly-like mass,
i.e. clot.
Thus, the process of blood coagulation completes.
Fibrin threads + Blood cells Clot
(red-coloured semisolid jelly-like mass)
Mention the factors affecting/influencing blood coagulation.
A. Factors Hastening/Accelerating/Increasing Blood Coagulation
Contact of blood with rough surface and injury to blood thrombocytes.
Temperature slightly excess than body temperature may increase blood coagulation.
Excessive slowness of blood flow.
Snake venom.
Presence of calcium salt.
Resting condition.
B. Factors Hindering/Retarding/Preventing Blood Coagulation
Contact with smooth surface.
Lowering body temperature.
Removal of Ca2+ ions from the blood by addition of Na, K and citrate ions.
Presence of greasy material like oil, wax or grease.
Deficiency of vitamin K.
Calcium deficiency in the blood.
Use of heparin.
Write a note on plasma proteins.
Plasma Proteins
“The number of proteins present in the blood plasma are called plasma proteins,” e.g. serum albumin, serum globulin, prothrombin, fibrinogen.
Functions of Plasma Proteins
Plasma proteins maintain colloidal osmotic pressure of the blood and help in regulating the distribution of fluid between the blood and tissues of the body.
Prothrombin and fibrinogen are essential for blood clotting process.
Plasma proteins mainly globulins are responsible for maintaining viscosity of blood which ultimately maintains the blood pressure.
The plasma proteins act as a buffer which maintain acid–
base balance.
Plasma proteins act as a storehouse of proteins, from which the tissues can draw proteins during inadequate protein diet.
Plasma proteins combine with certain substances and help to carry them in bloodstream.
Plasma proteins help in binding of drug and increase the duration of action of drugs.
Plasma globulins help in the formation of antibodies which give protection against infection.
Write a note on blood groups. Write a note on ABO group system. Explain how blood group matching is done.
• ABO blood group system was discovered by Karl Landsteiner in 1900.
The blood of one person is not always compatible with that of another person, hence before transfusion (donation) of blood, it must be tested or compatibility of acceptor’s blood is assured.
Only compatible blood is to be transfused.
If incompatible blood is transfused, then agglutination of erythrocytes occurs which leads to haemolysis of transfused blood cells (breakdown of RBCs). Therefore, Rh +ve blood is not given to Rh –ve persons.
There are four main blood groups: Blood group ‘A’, Blood group ‘B’, Blood group ‘AB’, Blood group ‘O’.
Blood donor: A person who gives or donates the blood to another person, is known as blood donor.
Blood recipient/blood acceptor: A person who requires or accepts the blood from another person is known as blood acceptor.
Universal donor: A person who donates the blood to all types of blood groups, is known as universal donor.
Universal acceptor: A person who accepts the blood from all the other blood groups is known as universal acceptor.
The membrane of erythrocytes contains antigens called agglutinogens and people have natural antibodies in the plasma known as agglutinins.
The agglutinogens are genetically determined and are of two types, i.e. ‘A’ and ‘B’.
The agglutinins in the plasma are of opposite type.
Blood group
Agglutinogens in RBCs
Agglutinin in plasma
‘A’
‘A’
‘b’
‘B’
‘B’
‘a’
‘AB’
‘A’ and ‘B’
No agglutinin
‘O’
No agglutinogen
‘a’ and ‘b’
Compatibility of Blood Groups (Matching of Blood Groups)
Blood group
Receives blood from
Donates blood to
‘A’
‘A’, ‘O’
‘A’, ‘AB’
‘B’
‘B’, ‘O’
‘B’, ‘AB’
‘AB’
‘A’, ‘B’, ‘AB’, ‘O’
‘AB’
‘O’
‘O’
‘A’, ‘B’, ‘AB’, ‘O’
Importance of Blood Group
Blood group study has a great value in blood transfusion.
Blood group study helps in the study of various blood disorders.
Blood group study is useful in forensic medicines.
Blood group study is helpful in experimental purposes.
13
What is Rh factor/Rh-antigen/Rhesus factor? Give its significance.
Rh Factor
It is an agglutinogen (antigen) of ‘Rhesus monkey’.
Apart from antigen ‘A’ and antigen ‘B’ about 80 to 90% of the people contain one or more antigens on the membranes of RBCs called Rh-antigen or Rhesus factor.
If Rh factor is present in the persons blood, then blood group is described as Rh +ve and if Rh factor is absent in the persons blood, then blood group is described as Rh –ve.
Significance/Importance of Rh Factor
Rh factor has a great value in blood transfusion because transfusion of Rh +ve blood to Rh –ve person stimulates the immune response which causes haemolysis of transfused blood cells.
Rh factor is helpful in detecting the blood group of child by considering father’s and mother’s blood group study.
14 Explain the terms in short.
(i) Thrombosis (Intravascular Clotting)
Definition: The process of formation of blood clot inside the blood vessel which may block the blood circulation is known as thrombosis.
The clot which is formed inside the blood vessel is known as ‘thrombus’. Thrombosis may be caused because of slow blood-flow or infection to inner side of the blood vessels.
Embolism (Em-in, bolusmass)
Definition: The process of formation of embolus in the bloodstream which blocks the blood circulation, is known as embolism.
The embolus may be bubble of air or in some cases blood clot or debris particle.
Phagocytosis
The process in which the cell engulfs or ingests the microbes, foreign particles and digests or destroys them within the cell is called phagocytosis, e.g. neutrophils and monocytes actively show phagocytic action.
Haemolysis (Laking of Blood)
Haemolysis means breakdown of RBCs.
The haemoglobin comes into the plasma after breakdown of RBCs. This phenomenon is known as laking of blood.
Fibrinolysis
The process of breakdown of fibrin threads within the clot by the action of proteolytic enzymes is known as fibrinolysis.
15 Explain various disorders of blood.
1. Anaemia
Anaemia means decrease in number of RBCs in the blood, or decrease in percentage of haemoglobin in the blood.
Causes/Reasons of Anaemia
Excessive loss of blood.
Failure of function of red bone marrow to produce RBCs.
Destruction of RBCs by haemolysis.
Deficiency of iron in the body.
Defective formation of RBCs.
Types of Anaemia
Pernicious anaemia. (iv) Sickle cell anaemia.
Megaloblastic anaemia. (v) Iron deficiency anaemia.
Microcytic anaemia.
Polycythemia
“It means an abnormal increase in RBCs in the blood.”
In this case, the skin and mucous membranes of the mouth are red and conjunctiva is also red.
Leukaemia
“Leukaemia means uncontrolled increase in production of WBCs in the blood.” It is also called cancer of blood.
Causes
Ionising radiations produced by X-rays.
Some chemicals cause the changes in the genetic make up of the white cell precursor.
Leucopenia
“Leucopenia means the conditions in which there is a decrease in number of WBCs below 4000/mm3 of blood.”
Leucocytosis
This is a condition in which the number of circulating leukocytes increases in the blood circulation.
Pathological leukocytes (abnormal) occurs when a blood leukocyte count is above 11,000/mm3 of blood.
Haemophilia (Bleeding Disease)
It is the condition in which bleeding occurs continuously even with a minor injury or a cut.
In this case, blood does not clot.
It is a hereditary disease which runs in the families.
Erythroblastosis Foetalis
It means the death of the foetus due to mass destruction of its red cells when their Rh –ve blood happens to receive Rhesus antibodies from the blood of mother.
When a pregnant women with Rh –ve blood bears an Rh
+ve baby, the problem appears in the last month of pregnancy, because at this stage there is a development of embryonic life of the child. The Rh +ve red blood cells of the baby pass into the blood of the mother who reacts by producing Rhesus antibodies which pass back into the blood of foetus.
As a result of this, the RBCs of the child get destroyed both before and after birth. This leads to death of the foetus. This condition is called erythroblastosis foetalis.
16 What is haemopoiesis/haematopoiesis? Explain the process of haemopoiesis.
Haemopoiesis/Haematopoiesis
Haemopoiesis is the process through which the body manufactures blood cells.
Haemopoiesis is from Greek language meaning ‘to make new blood’.
It occurs within the haemopoietic system which includes organs and tissues such as the bone marrow, liver and spleen.
Haemopoiesis begins early in the development of an embryo well before birth and continues for the life of an individual.
Process of Haemopoiesis
The rate of haemopoiesis depends on the body’s needs.
The body continuously manufactures new blood cells to replace old ones.
About 1% of the body’s blood cells must be replaced every day.
White blood cells have the shortest lifespan, sometimes surviving just a few hours to a few days, while red blood cells can last up to 120 days.
The process of haemopoiesis beigns with a stem cells. These stem cells multiplies and some of these new cells transform into precursor cells.
These immature cells soon devide and mature into blood components such as red and white cells or platelets.
The Lymphatic System
1 What is lymph? Give composition and functions of lymph.
Lymph
“The lymph is a thin, watery, clear modified tissue fluid which is formed by the passage substances from the blood capillaries into the tissue space by the process of diffusion.”
Composition
Water: 94%
Solids: 6%
Proteins
Fats
Carbohydrates
Urea
Non-nitrogenous substances
Creatinine
Other inorganic substances.
Composition of lymph is similar to blood plasma but concentration of dissolved substances is different.
The lymph contains lymphocytes but RBCs and thrombocytes are absent.
Functions of Lymph
Lymph helps to transport lymphocytes and extra-intestinal fluid from lymph gland into circulation.
It helps to return fluid and proteins from tissue to blood circulation.
40
It helps supply nutrients to such part of body where blood does not reach.
Lymph helps to carry emulsified fat from intestine to circulation.
Defensive mechanism: Lymph helps in drainage of bacteria and toxins along the lymphatics and traps them in lymph nodes.
2 Mention the functions of lymph gland/lymph node.
Functions of Lymph Gland/Lymph Node
Lymph node helps in filtration of lymph and removes microbes, their toxins and foreign bodies.
Lymph node produces and supply lymphocytes to blood.
Lymph node produces gamma-globulin (-globulin) which helps in immunological response of the body.
Lymph nodes prevents spread of cancer cells.
Lymph node makes screening of lymph by means of phagocytic action.
Lymph node acts as a mechanical filter to resist the entrance of poisonous substance into circulation.
Lymph node acts as first line of defense guarding respective areas through strategic points in the body.
3 What is lymph node? Explain the structure of lymph node/gland.
Lymph Node/Lymph Gland
“These are small oval or bean-shaped structures present in the course of lymphatic vessels.”
Lymph nodes are usually distributed in groups.
They are placed superficially and also deep in the body.
The main groups of lymph gland are present:
In neck
In the axial (arm)
In the thorax
In the abdomen
In legs, etc.
Section/Internal Structure of Lymph Node/Lymph Gland
Lymph node/lymph gland consists of following parts:
An outer dense fibrous tissue called capsule.
Capsule gives rise to fibrous band on inner side called trabeculae. Trabeculae divides substance of lymph node into irregular spaces.
The space between trabeculae contains lymphoid tissue which produces lymphocytes.
As many as 4 to 5 afferent lymph vessels may enter in lymph node while only one efferent lymph vessel carries lymph away from lymph node.
Each lymph node has concave surface called hilum where blood vessels supply blood to lymph node and efferent lymph vessel leaves.
4 What is spleen? Describe structure and mention the functions of spleen.
Spleen
Spleen is a dark purple-coloured lymphoid tissue.
It is usually 12 cm long, 6 cm wide and 2.5 cm thick.
It weighs about 100 g.
It is highly vascular and bean-shaped.
It lies between fundus of stomach and diaphragm.
Section of Spleen
Capsule
Splenic
pulp
Trabeculae
Lymph vessel Splenic vein Splenic artery
Spleen contains following structures:
An outer covering of fibroelastic tissue is called capsule.
Trabeculae are structures which arise from capsule on its inner side and divide the spleen into irregular spaces.
The space between trabeculae contains splenic pulp.
The splenic pulp contains a large number of lymphocytes.
Spleen is supplied by splenic artery and is drained by splenic vein.
Functions of Spleen
Spleen helps in formation of blood, i.e. RBCs are produced in spleen during foetal life.
Spleen acts as a storage of blood and may store erythrocytes and in emergency condition, they are supplied to body.
Destruction of blood: Spleen helps in destruction of matured erythrocytes and breakdowns into products such as bilirubin and iron which are passed to liver.
Spleen also forms lymphocytes.
Foreign particles, toxins and bacteria all are trapped by spleen and destroyed.
Spleen also produces antibodies.
5 Name the two main lymphatic ducts. How do they communicate with blood circulation?
There are two main lymphatic ducts which collect lymph from whole body and return into blood.
Right lymphatic duct: It receives lymph from right jugular trunk which drains right side of head, neck and right arm.
This duct communicates with right subclavian vein of circulatory system.
Left lymphatic duct (thoracic duct): It is the main collecting duct of lymphatic system which receives lymph from left side of head, neck, chest, left upper end and entire body below ribs.
This duct communicates with left subclavian vein of circulatory system.
6 Mention the functions of lymphatic system.
1. The lymphatic system acts as intermediate transport system between blood vascular system and cells.
Lymph glands produce lymphocytes.
Lymphatic fluid drains out excess fluid from the tissue back into the blood.
In addition to transporting nutrients to tissues, it removes waste materials from the site of their excretion.
Lymphocytes protect the body against infection.
It absorbs fat from the digested food in the small intestine.
Lymphocytes disintegrate to produce plasma proteins like -globulin.
Spleen as a lymphatic organ produces all types of blood cells during embryonic life. It also acts as a reservoir of blood which is supplied in emergency condition of the body.
Lymphatic system is rich in antibodies to counter the infections.
Thymus as a lymphatic organ produces T-lymphocytes to fight specific type of infections.
The Cardiovascular System
The continuous flow of blood throughout the human body, is known as blood circulation.
The blood is circulated throughout the body by heart and blood vessels.
1 Define different blood vessels.
(i) Veins: The vessels which collect the blood from different parts of the body and empty their contents into the heart, are called veins.
Arteries: The vessels which supply the blood from heart to different parts of the body are called arteries.
Arterioles: The smaller branches of arteries which distribute the blood to different parts of the body, are known as arterioles.
Venules: When several capillaries unite to form small veins, these are called venules.
Capillaries: Capillaries are very small, thin vessels which make connective link between arterioles and venules.
2 Differentiate between vein and artery.
Veins
Artery
(i)
The vessel which collects the blood from different parts of the body and empties its contents into the heart is called vein.
(i)
The vessel which supplies the blood from heart to different parts of the body is called artery.
(ii)
It is thin-walled.
(ii)
It is thick-walled.
Contd...
45
Veins
Artery
(iii)
The lumen is bigger.
(iii)
The lumen is smaller.
(iv)
Valves are present.
(iv)
Valves are absent.
(v)
Veins are more superficial as compared to arteries.
(v)
Arteries are placed deeper as compared to veins.
(vi)
Veins have less elastic tissue.
(vi)
Arteries consist of elastic fibres and smooth muscles.
(vii)
A number of venules unite to form veins.
(vii)
The smaller branches of arteries are called arterioles.
(viii)
Blood flow is slow.
(viii)
Blood flow is rapid.
(ix)
Blood moves smoothly.
(ix)
Blood moves in them with jerks.
(x)
Veins are bluish in appearance.
(x)
Arteries are red in appearance.
(xi)
Veins carry deoxygenated blood (impure blood) except pulmonary veins.
(xi)
Arteries carry oxygenated blood (pure blood) except pulmonary artery.
(xii)
Veins are full of blood after death.
(xii)
The arteries have no blood in them after death as heart stops beating.
3
Explain layers/walls/coverings/coats of the heart.
The human heart is composed of mainly three layers:
Pericardium: It is an outer covering made up of two sacs. Outer sac consists of a double layer of serous membrane. The cells of serous membrane secrete serous fluid into the space between two layers which lubricates these two layers, so that by lubricating action the heart moves freely. The serous fluid is called pericardial fluid.
Myocardium: It is the middle layer of heart which is made up of a specialized muscular tissue called ‘cardiac muscle’. The cardiac muscle fibres spread the impulse of contraction over a whole sheet of myocardium and contraction of heart takes place.
Endocardium: It is the innermost layer of heart. It forms lining to the myocardium. It is a smooth membrane consisting of flattened epithelial cells continuous with the lining of blood vessels and also the valves.
4 Draw and label a diagram of internal structure/interior of heart (LS of heart).
5 Explain various parts of heart/interior of the heart.
Description of Heart
The interior of heart is divided into right and left side by a vertical septum, known as interventricular septum.
Each side is further divided into an upper and lower chambers by the valves.
The upper chambers are called atrias or auricles and lower chambers are called ventricles.
Hence, the heart has four chambers:
Right atrium (iii) Left atrium
Right ventricle (iv) Left ventricle
The two largest veins of the body namely superior vena cava (SVC) and inferior vena cava (IVC) collect deoxygenated blood from the superior and inferior parts of the body and empty their contents into the right atrium of the heart.
Two pairs of pulmonary veins collect the blood from two lungs and pour their contents into the left atrium.
The pulmonary artery originating from right ventricle which further divides into right and left pulmonary branches carrying the blood towards the lungs.
Aorta is the largest artery originating from left ventricle, which further divides into a number of arteries and arterioles supplying oxygenated blood to different parts of the body.
Valves of the Heart
The heart has four main valves, namely:
Tricuspid valve: This valve is present separating right atrium from the right ventricle. Hence, it is also called right atrioventricular valve. Opening of this valve is guarded by three cusps.
Function: This valve prevents back flow of blood from right ventricle to right atrium.
Bicuspid valve: This valve is present separating left atrium from the left ventricle. Hence, it is also called left atrioventricular valve. This valve is also known as mitral valve. The opening of this valve is guarded by two cusps.
Function: This valve prevents back flow of blood from left ventricle to left atrium.
Pulmonary valve: This valve is present between pulmonary artery and right ventricle.
Function: This valve prevents the back flow of blood from pulmonary artery to the right ventricle.
Aortic valve: This valve is present between aorta and left ventricle.
Function: This valve prevents the back flow of blood from aorta to left ventricle.
Actions of Valves/Mechanism of Action of Valves
When blood enters in both atria they are full and thus get contracted. In this case, tricuspid and bicuspid valves open and blood is forced into the ventricles, respectively. When ventricles contract, both pulmonary and aortic valves open and blood is forced into aorta and pulmonary artery. At the same time, tricuspid and bicuspid valves are closed towards atrium. It should be noted that both atria contract simultaneously. Similarly, ventricles also contract simultaneously.
6 Define cardiac cycle. Explain various events taking place in cardiac cycle. Or Write a note on cardiac cycle.
Cardiac Cycle
“The events which take place during the circulation of blood through the heart, are collectively called cardiac cycle.”
Cardiac Cycle Time
“The time required for one complete cardiac cycle is known as cardiac cycle time.”
Cardiac cycle time is 0.8 sec.
There are 72 cardiac cycles taking place in 1 minute.
The cardiac cycle involves four main events, namely:
(a) Atrial systole, (b) atrial diastole, (c) ventricular systole,
ventricular diastole.
Sinoatrial node
(SA node/ pacemaker)
IVC
Atrioventricular node (AV node)
Bundle of His Purkinje fibres
SVC
Septum
Atrial systole
0.1 sec
0.4 sec
complete cardiac diastole
0.3 sec
ventricular systole
Cardiac cycle time
Systole: The contraction of chamber of heart is known as systole.
Diastole: The relaxation of chamber of heart is known as diastole.
Atrial systole: In this condition, the blood comes into both atria and they are full of blood. Due to this, pressure in the atria increases which stimulates SA node present in the right atrium. SA node produces impulse of contraction which is spread over both atria and atria get contracted. This stage is known as atrial systole.
Atrial diastole: After atrial systole, the blood is forced into the ventricle, then atria are relaxed and there is no impulse of contraction on the atrium. This stage is known as atrial diastole.
Ventricular systole: When pressure in the ventricle increases, at the same time the impulse of contraction is carried by AV node towards the ventricles through the bundle of His which is a conducting tissue present in the septum. This bundle of His further divides into two branches forming a network of Purkinje fibres. These fibres spread the impulse of contraction over both the ventricles and thus ventricles get contracted. This stage is known as ventricular systole.
Ventricular diastole: After ventricular systole, blood is forced into pulmonary artery and aorta. In this stage, ventricles are relaxed. This is known as ventricular diastole.
In this way, cardiac cycle completes within 0.8 sec.
7 Describe the systemic/greater circulation of blood.
Systemic Circulation
“The flow of blood from the left ventricle to various parts of the body and back to the right atrium of the heart, is called systemic circulation.”
Description
The oxygenated blood from the left ventricle is forced into the aorta.
The blood from the aorta divides into arteries, arterioles and finally comes into the blood capillaries.
The walls of blood capillaries are very thin, hence oxygen and nutrients from blood in the capillaries diffuse into the tissue fluid. At the same time, CO2 from the tissue fluid diffuses inside the blood in the capillaries and blood becomes deoxygenated (impure).
A number of capillaries unite to form venules which collect deoxygenated blood which is then carried by veins towards SVC and IVC. Then from SVC and IVC this deoxygenated (impure) blood passes into the right atrium of the heart.
This course of blood from left ventricle to right atrium is known as systemic circulation/greater circulation.
8 Explain pulmonary circulation of blood/lesser circulation.
Pulmonary Circulation
“The flow of blood from right ventricle to the left atrium via lungs is known as pulmonary circulation.”
Description
The deoxygenated (impure) blood from right ventricle is forced into pulmonary artery which divides into right and
left pulmonary arteries carrying blood towards right and left lung, respectively.
These arteries divide and redivide into network of capillaries surrounding the alveoli of lungs.
The walls of capillary and alveoli forms a double membrane called alveolar membrane. The oxygen from alveoli diffuses through these two membranes and passes into the blood in the capillaries and blood becomes oxygenated.
Similarly, CO2 from the blood in the capillaries diffuses into the alveoli of lungs and expelled out through the nose by expiration.
The oxygenated blood from two lungs is collected by two pairs of pulmonary veins and pour their contents into the left atrium.
In this way, pulmonary circulation is complete.
Importance of Pulmonary Circulation
Gaseous exchange: It helps in exchange of gases within alveoli of lungs.
Filtering function: The fine pulmonary blood vessels act as a filter which traps the emboli that passes through
pulmonary capillaries and prevents blocking of vessels in the brain and heart.
Nutrition: This circulation maintains nutrition of lung tissue.
Reservoir for left ventricle: The left ventricular output is fully dependent upon the return of blood from pulmonary veins into the left atrium. So, any alteration of pulmonary veins will alter the left ventricular function.
9 Describe hepatic portal circulation/portal circulation.
Hepatic Portal Circulation
“The venous blood from various digestive organs is collected by portal vein carried to the liver first and then into right atrium via IVC. This is known as hepatic portal circulation.”
Description
The venous blood from digestive organs such as small intestine, stomach, pancreas is collected by portal vein. Instead of pouring its contents into the IVC, it is poured into
the liver. Hence, the high concentration of nutrient materials goes to the liver first.
Then from the liver blood containing proportionate nutrients is carried by IVC into the right atrium of the heart.
This course of blood through the liver is called portal circulation.
Importance of Hepatic Portal Circulation
Portal circulation is important because the blood containing nutrients from the digestive organs is taken via liver to heart. In the liver, these nutrients are modified and according to the need of the body, they are transported in the blood circulation and supplied to various parts of the body via heart.
Thus, portal circulation helps in regulating the nutrient material supply to various parts of the body.
Write a note on coronary blood circulation.
Coronary Circulation
Coronary circulation is the circulation of blood to heart muscle (myocardium).
For nourishment of its own muscular walls, the heart has own circulation which consists of coronary arteries and veins.
Coronary arteries supply oxygenated blood to the heart muscle and coronary veins drain away the blood once it has been deoxygenated.
Coronary arteries:
The right and left coronary arteries are the branches from the ascending aorta and supply oxygenated blood to the myocardium.
The left coronary artery passes inferier to left auricle and supplies the oxygenated blood to both the ventricles and left atrium.
The right coronary artery supplies the oxygenated blood to the right atrium.
Coronary veins
After the blood passes through coronary arteries, it flows into capillaries where it delivers oxygen and
nutrients and collects carbon dioxide and wastes, and then into coronary vein.
The deoxygenated blood then drains into a large vascular sinus on the posterior surface of the heart, called coronary sinus, which empties into the right atrium.
In this way, the blood is supplied to heart muscles (myocardium) by coronary arteries. This is called coronary blood circulation.
Show diagrammatically the ‘conducting system of heart’ or blood flow through heart, or blood supply from right side to left side of the heart.
Explain the terms.
1. Stroke Volume
“It is the amount of blood ejected from the heart by each contraction of the ventricles.”
Normal value: 70 ml
Cardiac Output
“It is the amount of blood ejected from the heart in each minute by the contraction of ventricles.”
Cardiac output = Stroke volume Heart rate
= 70 72
= 5040 ml
Normal value of cardiac output = 5040 ml
SA Node (SAN)/Sinuatrial Node/Pacemaker
It is situated in the wall of right atrium. It originates the impulse of contraction and maintains rhythm, hence also called pacemaker.
Function
It originates impulse of first contraction.
It is responsible for contraction of both atria.
AV Node
Atrioventricular node is present at the base of septum. From the AV node, a band of muscle starts called bundle of His which divides into many branches and forms a network of fibres in the walls of ventricles called Purkinje fibres.
Function: It collects impulses from SA node passes throughout both ventricles via bundle of His and Purkinje fibres.
Define blood pressure. Explain factors affecting blood pressure.
Blood Pressure
“The lateral pressure exerted by blood on the walls of blood vessels while flowing through it, is called blood pressure.”
Systolic BP: The pressure exerted during systole (contraction of chamber), is called systolic blood pressure.
Diastolic BP: The pressure exerted during diastole (relaxation of chamber), is called diastolic blood pressure.
Pulse pressure: The difference between systolic and diastolic blood pressure is called pulse pressure.
The blood pressure is measured by an instrument called “sphygmomanometer”.
The blood pressure is measured in terms of mm of Hg.
Normal values of blood:
In adult: 120/80 mm of Hg.
In childhood: 80 to 100/60 mm of Hg.
In young adults: Systolic BP—110 to 115 mm of Hg.
Diastolic BP—60 to 70 mm of Hg.
Factors Affecting/Influencing BP
Age: BP increases with age.
Sex: In females, both systolic and diastolic pressure are slightly lower than in males up to the ages of 45 to 50 years.
Exercise: During heavy exercise the blood pressure is higher.
Sleep: During sleep, the systolic BP falls by about 15 to 20 mm of Hg.
Emotional conditions: Emotions cause increase of systolic BP, i.e. with emotional stress and more excitement conditions, blood pressure increases.
After ingestion of meals: After meals, there is a slight rise of systolic BP.
Endocrine control: Pituitary gland, thyroid gland and adrenal gland control the BP. Their hypersecretion causes increase in BP and hyposecretion causes decrease in BP.
Posture of the body (position): The diastolic pressure is higher in the standing position than the laydown position or sitting position.
How is blood pressure recorded/measured clinically? Give the procedure of measurement of BP.
BP is measured by an instrument known as sphygmo-manometer.
Methods of Measurement of Blood Pressure
Oscillatory method
Auscultatory method
Palpatory method
Auscultatory Method
For the measurement of BP, the patient must be at rest, both physically and mentally.
The rubber bag is wrapped around the upper arm. With the help of pressure pump, the air is pushed into the rubber bag until the pressure of 200 mm of Hg is reached on the mercury manometer.
This pressure obliterates the brachial arteries.
The pulse disappears at the elbow joint.
Stethoscope is kept at the elbow and heart sounds are observed.
The air in the bag is slowly released. The stage at which first pulse is heard in which a soft puffing noise is heard at the elbow is noted on the manometer. This is known as systolic BP.
The air from the rubber bag is further released and the stage at which heart sound stops is recorded on the manometer. This is known as diastolic blood pressure.
In this way, blood pressure is measured clinically.
Measurement of BP
Mention different cardiovascular disorders.
Explain the terms.
(a) Congestive heart failure (CHF/CCF): In this condition, function of right ventricle is failed, due to which blood is congested in every part of the body. The congestion throughout the systemic circulation takes place. The affected organs are liver, spleen, and kidneys.
Angina pectoris: It means pain in the chest due to an abnormal coronary blood circulation.
Congenital heart disease: Heart disease may be congenital. Most of the defects are observed in the formation of septum dividing heart into right and left side. Congenital defects are the points of weakness against bacterial infection.
Myocardial infarction (loss of impulse in myocardium): Heart is supplied the blood by coronary arteries. When the vessels of coronary arteries get thickened due to deposition of fat inside it, the narrowing of artery or thrombus present in it causes lower blood towards the
walls of the heart is called coronary thrombosis. Because of this, the cells present in the walls are dead (yellowish mass of dead cells) and the heart stops working which is called myocardial infarction.
Arteriosclerosis: This is a disease of artery where there is a deposition of fatty material in the walls of artery. This leads to thickening of artery which decreases the internal diameter of artery. This causes resistance in blood circulation and thus increases BP. Cholesterol is one of the important constituents which is a causative factor for arteriosclerosis. In arteriosclerosis there may be a patch generation developed in the ‘tunica media’ of large and medium-sized arteries. This patch consists of accumulation of cholesterol compounds, excess of smooth muscles and fibroelastic cells. When these ‘plaques’ grow, they spread along the walls of artery forming swelling which may produce resistance in blood circulation. This condition is called arteriosclerosis.
Varicosed vein: In this condition, the valves present in the veins are dilated so that they do not prevent back flow of blood.
Aneurysm: Dilatation of the wall of an artery, forming a blood filled sac is called aneurysm of the artery. It occurs most frequently in the descending aorta, and eventually may rupture, causing haemorrhage and death. Chest pain, laboured breathing are the main symptoms associated with aneurysm in the aorta in the thoracic region. A congenital defect in a cerebral artery
known as berry aneurysm is the most common cause of subarachnoid haemorrhage.
Stroke: Stroke is an interruption of blood supply to the brain. The most common cause of stroke is occulsion of cerebral artery by thrombosis. Other causes include thromboembolism, blockage of an artery by a fragment of blood clot that has broken from its site of origin and haemorrhage due to rupture of an artery.
Stenosis: An abnormal narrowing of blood vessel.
Septal defects: This defect is due to small holes within the septum between the atria or ventricles. Small openings usually cause little difficulty. Large openings can result in death shortly after birth.
Write a note on ECG (electrocardiogram).
ECG: When muscle contracts, there is a change in electrical potential across the membrane of cardiac muscle fibres. As the body fluids and tissues are good conductors of electrical charges, during contraction of myocardium can be detected by attaching the electrode to the surface of the body. The pattern of electrical activity may be printed on the paper. This tracing is known as electrocardiogram (ECG).
Normal pattern of ECG
Interpretation of human ECG shows following waves ‘P’, ‘Q’, ‘R’, ‘S’, ‘T’: ‘P’ is of atrial origin, hence called ‘atrial complex’ while Q, R, S, T are of ventricular origin, hence collectively known as ‘ventricular complex’.
‘P’: It is the first upward deflection. It is small but constant wave having rounded or pointed top. This wave is caused by impulse of contraction within the atria. The normal ‘P’ indicates:
The impulse is originating at the SA node.
The impulse spreads over atria in usual direction.
‘Q’, ‘R’, ‘S’, ‘T’: These four waves are caused by ventricular activity and are collectively called ventricular complex. These waves indicate spread of impulse of contraction through conductive tissue of ventricular muscle.
‘Q’: As soon as the impulse arises at the muscular part of the septum, the latter contracts producing first wave ‘Q’. Hence, ‘Q’ is caused by activity of septum.
‘R’: ‘R’ is the most constant wave having tallest amplitude. ‘R’ is mainly caused by activity of right ventricle.
‘S’: It is caused by activity of left ventricle.
‘T’: ‘R’ is followed by long period after which comes the last upward deflection called ‘T’. ‘T’ is caused by action current due to confraction of basal part of ventricles.
Importance of EGC
ECG has diagnostic value. The changes in ECG are observed in the cases of disorders of heart and blood vessels.
ECG gives accurate information of the conditions of atrium and ventricle almost in all of its functional areas.
In cardiac abnormalities characteristic variations occurred in ECG are helpful in identifying various disorders of heart.
Cardiac arrythmia, ventricular premature beats, ventricular fibrillations are disorders of heart recorded by ECG.
Write in brief about “heart sounds”.
Heart sounds are produced due to contractions and relaxations of the heart muscles and opening and closing of the valves of heart.
When ear or the diaphragm of a stethoscope is placed on the chest wall a little below the left nipple and slightly nearer the midline, the heartbeat/heart sound can be heard.
Two sounds separated by a short pause can be clearly
distinguished. They are described in words as ‘lup’, ‘dup’.
The first sound ‘lup’, is fairly loud, low-pitched and prolonged and is due to the closure of the atrioventricular valves. This corresponds to ventricular systole.
The second sound ‘dup’ is shorter, sharper and high-pitched than the first sound. It is caused due to the closure of the aortic and pulmonary valves. This corresponds with atrial systole.
The first heart sound is followed by the second sound, after a short pause.
The Respiratory System
1 Define respiration. Explain types of respiration.
Respiration
The exchange of gases (O2 and CO2) occurring between atmosphere and body cells, is known as respiration.
Types of Respiration
External Respiration
“The exchange of gases occurring between atmosphere and blood taking place in the lungs, is known as external respiration.”
Internal Respiration (Tissue Respiration)
“The exchange of gases occurring between blood and body cells is known as internal/tissue respiration.”
2 Name the organs/parts of respiratory system.
Organs of Respiratory System
Nose
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
Lungs
Pleural layers (coverings)
Parietal pleura
Visceral pleura
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The main respiratory muscles
Intercostal muscles
Diaphragm.
3 Sketch and label a diagram of respiratory system.
The respiratory system
4 Describe in brief various parts of respiratory system.
1. Nose
It is the first part of respiratory system through which air enters into the body. The nose is also an organ of sense of smell. The nose is lined with very vascular ciliated columnar epithelium.
Functions
Filtration of air.
Warming of air.
Moistening of air.
Pharynx
The pharynx is a part of both respiratory and digestive system.
Anatomically, pharynx is divided into 3 parts:
Nasopharynx: It is a part of pharynx present nearest to nasal cavity.
Oropharynx: It is a part of pharynx present behind the oral cavity.
Laryngopharynx: It is a part of pharynx present nearest to larynx region.
Functions
It helps in warming and moistening air.
It helps in filtration of incoming air.
Pharyngeal tonsils (adenoids) prevent the pathogens from entering the body.
Pharynx has respiratory as well as digestive function.
Larynx
The larynx is called ‘voice box’ or ‘sound box’.
Larynx consists of arrangement of vocal cords.
Vocal cords are responsible for production of sound.
The larynx is supported by approximately 9 pieces of cartilages which are as follows:
Thyroid cartilage—1
Arytenoid cartilages—2
Cricoid cartilage—1
Cuneiform and corniculate—2 each (04)
Epiglottis—1
Functions of Larynx
The larynx acts as a passage between pharynx and trachea.
The air is further warmed, moistened and filtered in the larynx.
The vocal cord arrangement in the larynx helps in the production of sound.
The cartilages of larynx help in the process of swallowing by its upward and downward movements.
Trachea
The trachea is a windpipe and is continuous with larynx.
The trachea is made up of 16 to 20 C-shaped rings of hyaline cartilages.
These cartilages are connected by fibrous tissue having opening at the back side.
Functions
It provides large passage for respiration.
The C-shaped cartilages of trachea keep it permanently open for the passage of air.
The cells of trachea secrete the mucus which is also helpful for removing the dust particles or bacteria and also helps for moistening of incoming air.
5 Describe the structure of lungs.
Lungs
Lungs are two in number and are the principal organs of respiration.
The lungs are cone-shaped with apex above.
The base of the lung is resting on the floor of the thoracic cavity, i.e. diaphragm.
The right lung has three lobes and left lung has two lobes.
Each lobe is composed of a number of lobules and contains small bronchioles.
The lung tissue is elastic, porous and spongy in nature.
The lung tissue is richly supplied with blood vessels.
Each lung is surrounded by double serous membrane called pleura.
Pleuras are composed of two layers:
Parietal pleura (outer)
Visceral pleura (inner).
In between these pleural layers, there is a serous fluid which lubricates the surface and prevents the friction between the lungs and chest wall during respiratory movements.
Functions of Lungs
The lungs are main organs of respiration in which exchange of gases takes place.
6 Explain mechanism/process of respiration (breathing).
OR Describe regulation of respiration.
Mechanism of Respiration
Expansion and contraction of lungs show that a regular exchange of gases takes place between alveoli and external air.
This depends upon the arrangement of pleura, relaxation of intercostal muscles and diaphragm.
There are approximately 15 cycles of respiration occurring per minute in an adult during normal respiration.
The process of respiration involves three stages:
Inspiration: In this stage pressure within the lung is lesser than the atmospheric pressure. The diaphragm is relaxed. Intercostal muscles are also relaxed. Due to this the air is forced into the lungs through respiratory passage and size of thoracic cavity gradually increases due to entry of air in the lungs.
This is known as inspiration.
Expiration: In this stage, the pressure within the lung is greater than atmospheric pressure. In this stage, diaphragm is pulled upward, exerting a pressure on both lungs. At the same time intercostal muscles get contracted and thus air is forced outside the lung and thus expiration takes place.
Pause: After expiration there is a little gap called pause and again second cycle of respiration takes place.
7 Define tissue respiration. Explain physiology of tissue respiration.
• Tissue respiration: The exchange of gases takes place in between cells or tissues of the body and blood which is known as tissue respiration.
Physiology of tissue respiration/internal respiration
The oxygenated blood is supplied to all the tissues of the body by arteries which further divide into arterioles.
The exchange of gases takes place between arterial end of the capillary and tissue fluid.
Since the concentration of CO2 is maximum in arterial blood, oxygen diffuses into the tissue fluid and then it is supplied to the tissues and cells of the body.
On the other hand, concentration of CO2 is maximum in tissue fluid, thus CO2 diffuses inside the blood capillaries and blood becomes deoxygenated which is carried by venules into the veins.
In this way, exchange of gases takes place between tissues and blood.
The oxygen and CO2 are carried in the blood in the form of oxyhaemoglobin and carboxyhaemoglobin.
Hb + O2 HbO2 (Oxyhaemoglobin)
Hb + CO2 HbCO2 (Carboxyhaemoglobin)
8 Define and give normal values of respiratory volumes/ respiratory parameters.
1. Vital Capacity
“The volume of air that can be made to pass into and out of the lungs by most forceful inspiration and expiration, is known as vital capacity.”
Normal value: 3 to 5 litres.
Tidal Volume
“The amount of air which is inspired and expired in an ordinary quite breathing is known as tidal volume.”
Normal value: 500 ml.
Inspiratory Reserve Volume
“The amount of air that can be breathed inside and above the tidal volume by deepest possible inspiration, is known as inspiratory reserve volume.”
Normal value: 1800 to 2000 ml.
Expiratory Reserve Volume
“The amount of air that can be breathed out after forceful expiration above the tidal volume, is known as expiratory reserve volume.”
Normal value: 1400 ml.
Residual Volume
“The amount of air remaining in the lungs after the most powerful expiration, is known as residual volume.”
Normal value: 1200 to 1500 ml.
Total Lung Capacity
“It is the sum of vital capacity and residual volume.”
Total lung capacity = Vital capacity + Residual volume
c v
TLC = V + R
9 Explain the terms.
1. Cheyne-Stokes breathing: In this type of breathing there is an alternate increase and decrease in rate and depth of respiration followed by intermittent apnoea (difficulty in breathing).
It is present in coma condition, poisoning, shock condition, head injury and other terminal stages of life.
Bronchial asthma: Asthma is a chronic disease in which the patient has difficulty in breathing.
Bronchial asthma is a clinical syndrome characterised by breathlessness and cough due to airway resistance in the narrowed bronchi. The narrowing of bronchi is due to bronchospasm edema of bronchial mucosa and thick sticky mucus in the branchial lumen. The patient with bronchial asthma has hyper-reactivity of bronchi which constricts due to allergens, physical and chemical irritants, infection, psychological and hereditary factors.
Anoxia: It means lack of proper pulmonary ventilation due to non-availability of O2.
Hypoxia: A condition in which the tissue is not sup-
plied with enough O2.
Dyspnoea: Poor pulmonary ventilation, i.e. deficiency of O2 to lungs and tissues.
Apnoea: It means difficulty in breathing.
2
Hypoxaemia: Decrease in arterial O
tension.
2
Hypocapnia: Decrease in arterial CO
Hypercapnia: Increase in arterial CO
tension. tension.
2
The Digestive System
1 Sketch and label a diagram of digestive system/ alimentary canal.
Digestive system/alimentary canal
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2 Enlist different organs/parts of the digestive system/ alimentary canal.
Digestive system
Alimentary canal Accessory organs
Mouth cavity/buccal cavity/oral cavity
Pharynx
Oesophagus
Stomach
Small intestine
Duodenum
Jejunum
Ileum
Large intestine
Caecum
Colons
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Appendix
Rectum
Anus
Teeth
Tongue
Salivary glands
Liver
Gallbladder
Pancreas
3 Explain main activities/functions of digestive system/ alimentary canal.
The main activities of alimentary canal are:
Ingestion: The process of taking the food into the alimentary canal (i.e. in mouth) is called ingestion.
Mastication: The process in which there is a movement of jaws, teeth, cheeks, lips and tongue during which the food is cut, ground into smaller particles and mixed with saliva to form a soft mass (bolus) which is then swallowed, is called mastication.
Deglutition: The process of swallowing the food is called deglutition. Deglutition is the main function of oesophagus.
Digestion: Digestion is the process of conversion of complex food material into simpler form so that it is readily absorbed through the walls of alimentary canal into blood circulation.
Absorption: The process by which digested food substances pass through the walls of some organs of alimentary canal into the blood and lymph capillary for circulation around the body. This is known as absorption.
Excretion/defaecation/elimination: It is the process by which the waste materials which are not digested are removed from the body.
4 Write a note on salivary glands.
There are three pairs of salivary glands present in the mouth cavity and they help in the secretion of saliva.
Salivary glands are as follows:
Parotid glands: These are present one on each side below and slightly in front of the ear.
Submandibular glands: They are present in the region of the mandible bone.
Sublingual glands: These are located beneath the tongue on each side.
Function of Salivary Glands
The function of salivary glands is secretion of saliva which is stimulated by the sight, smell and presence of food in the mouth.
5 What is saliva? Give the composition and functions of saliva.
Saliva
“Saliva is a mixed secretion of the three pairs of salivary glands (parotid, submandibular, sublingual glands) which gives moistening to the mouth also cleans the teeth, tongue and helps in the process of mastication.”
Composition of Saliva
Water: 10%
Ptyalin: Salivary enzyme
Mucin: Thick lubricant
Calcium salts: In small amounts.
Functions of Saliva
Saliva constantly keeps the mouth cavity clean and moist.
Saliva moistens and lubricates the food material so that it forms a soft mass (bolus) which is suitable for swallowing.
Ptyalin which is salivary enzyme, converts cooked starches into maltose.
Saliva acts as a solvent in which the substances get dissolved and stimulate taste buds.
Saliva has cleansing action and helps to keep the mouth, teeth and tongue free from debris.
Saliva helps in excretion of heavy metals, urea and certain other substances.
The dry food material stimulates the sense of taste only after mixing with saliva.
6 Explain the structure of stomach in brief. Mention the functions of stomach.
Stomach is a J-shaped portion of alimentary canal situated between oesophagus and beginning of small intestine. Stomach has three parts—‘fundus’, ‘body’ and ‘pyloric antrum’. The muscular layer present in the stomach allows for the peristaltic movements. The gastric glands are present in the mucous membrane of stomach which secrete gastric juice containing various digestive enzymes.
Functions of Stomach
It acts as a storage of food material.
The water present in stomach further liquifies food material which is swallowed.
It helps in mixing of food.
The gastric glands present in stomach secrete gastric juice which helps in chemical digestion.
Stomach helps in absorption of water, glucose and certain drugs.
7 What is gastric juice? Give its composition and functions.
Gastric Juice
Gastric juice is secreted by special secretory glands (gastric glands) in the gastric mucosa (stomach).
Composition of Gastric Juice
Water
Minerals
Mucus
Dilute HCl
Intrinsic factor
Enzymes—pepsinogen (pepsin), renin.
Functions of Gastric Juice
Water present in gastric juice further liquifies the food material in the stomach.
Dilute HCl:
It acidifies the food and stops the action of ptyalin.
It kills many microbes.
It provides acid environment needed for effective digestion by pepsin.
The enzyme pepsin converts proteins into peptones.
Intrinsic factor present in gastric juice is necessary for absorption of vitamin B12.
The mucus prevents mechanical injury to the walls of
stomach by lubricating the contents of stomach.
The mucus prevents chemical injury by acting as a barrier between stomach wall and other chemical constituents.
8 Explain anatomy and physiology of small intestine.
Small Intestine
It is present in between stomach and large intestine. It is about 5 meters in length and is divided into three parts.
Duodenum (25 cm)
Jejunum (2 m)
Ileum (3 m)
The inner surface of small intestine is greatly increased by circular folds and by finger-like projections called villi. Blood vessels and lymph vessels are present in the villi. A large number of tubular glands are present in the intestine, called intestinal glands and they secrete intestinal juice.
Composition of Intestinal Juice
Water
Mineral salts
Enterokinase, amylase, lipase, peptidase, sucrase maltase, lactase enzymes.
Functions of Small Intestine
The peristaltic movements help to forward the food material.
It secretes intestinal juice containing enzymes which are necessary for chemical digestion of food.
It helps in absorption and digestion of food.
The complete digestion and absorption of carbohydrates, proteins and fats take place in the small intestine.
It gives protection against infection by microbes that have survived antimicrobial action of HCl in the stomach.
9 Describe the anatomy/structure of large intestine.
Mention the functions of large intestine.
Anatomy of Large Intestine
It measures about 1.5 m in length. The ileum part of small intestine joins with large intestine in caecum. The small outward projection present at the base of caecum is called appendix.
The large intestine has mainly four colons.
Ascending colon
Transverse colon
Descending colon
Sigmoid colon.
Structurally, it resembles small intestine but diameter is large and length is short.
The large intestine has three main walls.
Inner mucosa: The villi are present in the inner surface of the mucosa and goblet cells are present in this layer which secrete mucus.
Submucosa: It is the middle layer which contains lymph nodules.
Muscular coat: It consists of a layer of circular muscles inside and longitudinal muscles outside.
Functions of Large Intestine
It helps in absorption of remaining glucose, amino acids, vitamins and certain drugs.
It gives consistency to the contents of large intestine by absorption of water from the contents and the stools become semisolid in nature.
The mucus secreted by goblet cells of large intestine prevents mechanical irritation and acts as a lubricant.
The appendix (a collection of lymphoid tissue) prevents the infection.
The microflora of large intestine synthesize vitamin K, folic acid and vitamin B12.
The heavy metals are excreted from the blood into the large
intestine.
Write a note on pancreas.
Pancreas
It is an accessary gland which empties its contents into duodenum. Pancreas is a pale grey gland consisting of broad head, body and narrow tail.
The pancreas consists of large number of ‘lobules’. Each lobule is drained by a small duct and they unite to form a large pancreatic duct. The pancreatic gland secretes pancreatic juice.
Composition of Pancreatic Juice
Water
Mineral salts
Trypsinogen (trypsin)
Chymotrypsin (chymotrypsinogen)
Amylase
Lipase
Functions of Pancreas
Exocrine Functions of Pancreas
Pancreatic juice is an exocrine secretion which performs following important functions.
Trypsin and chymotrypsin help in digestion of proteins by converting peptones into polypeptides.
Amylase helps in digestion of carbohydrates which converts polysaccharides into disaccharides.
The lipase enzyme helps in digestion of fats by converting fats into fatty acids and glycerol.
Endocrine Functions of Pancreas
The islets of Langerhans cells in the pancreas secrete two important hormones, namely glucagon (by -cells) and insulin (-cells) which perform following functions.
Insulin reduces blood sugar level.
Glucagon converts liver glycogen into glucose.
Write in brief about gallbladder.
Gallbladder is a pear-shaped sac attached under the surface of right lobe of liver. It has three main parts, namely neck, body and fundus.
Functions of Gallbladder
It helps to collect the bile from liver.
It acts as a temporary storage of bile.
It helps to concentrate the bile.
It helps in passage of bile towards the duodenum by contraction of its muscular coat.
Define bile. Give the composition and functions of bile.
Bile
Bile is an external secretion of liver which is produced in dilute form and is then concentrated by gallbladder.
Composition of Bile
Water: 90%
Bile salts:
Sodium glycocholate
Sodium taurocholate
Bile pigments:
Bilirubin
Biliverdin
Cholesterol
Mucus.
Functions of Bile
Bile salts are responsible for digestion and absorption of fats.
Bile salts help in absorption of lipid-soluble vitamins (fat-soluble).
Bile salts help in emulsification of fats by reducing surface tension.
Certain substances are excreted through the bile, e.g. toxins, bacteria, some metals like zinc, copper.
Bile helps to maintain the pH of duodenal contents.
The mucus of bile acts as a buffer and also has lubricating action.
Bile secretion colourises and deodorises the faeces.
Mention the functions of liver.
Functions of Liver
The hepatic cells of liver secrete the bile which is necessary for digestion and absorption of fats.
Liver acts as a storage of glycogen.
Liver helps in the formation of urea which is then carried to the kidney and thrown out in the form of urine.
Liver helps in metabolism of fats.
Liver helps in production of heat which helps in maintaining body temperature.
Liver performs detoxication function.
Liver helps in storage of iron in the form of protein compound called ferritin.
Liver helps in storage of vitamins A, D, E, K and B12.
Functions of liver related to blood:
Formation of RBCs in foetal life.
Destruction of RBCs and formation of bile pigments.
Formation of plasma proteins such as albumin, globulin, prothrombin, fibrinogen.
Formation of heparin which is a natural anticoagulant present in the blood.
Explain digestion of carbohydrates, proteins and fats.
Secretion Carbohydrates
Proteins
Fats
Saliva
Gastric juice
Pancreatic juice
Intestinal juice
End products of digestion
Ptyalin acts on polysaccharides
Amylase converts polysaccharides into disaccharides
Sucrase, maltose, lactase convert disaccharides into monosaccharides
Glucose
Pepsin converts proteins into peptones
Trypsin and chymotrypsin convert peptones into polypeptides
Peptides convert polypeptides into amino
acids Amino acids
Gastric lipase of little importance
Lipase (bile salts) converts fats into fatty acid and glycerol
Fatty acids and glycerol
Define the terms ‘metabolism’ and ‘basal metabolic rate, (BMR).
Metabolism
The chemical changes occurring during oxidation of nutrient food materials and releasing energy for various activities of the body is called metabolism.
BMR (Basal Metabolic Rate)
“It is the minimum energy required by the body per day, when an individual is at the rest and has eaten no food for 12 hours.”
The unit of measurement of BMR is kilojoules/m2/hr
Normal values of BMR:
Men: 170 kJ/m2/hr
Women: 150 kJ/m2/hr
Explain various disorders of digestive system.
(a) Peptic Ulcer
It means ulceration of gastrointestinal mucosa caused by acidic gastric juice. There are two types of ulcers.
Stomach ulcers
Duodenal ulcers.
Appendicitis
It means swelling or inflammation of appendix.
Achlorhydria
It means absence or less secretion of dilute HCl in the gastric juice of stomach.
Jaundice
When bile appears in the urine, the condition is called jaundice. The yellow colouration of the skin and conjunctiva is the primary symptom of jaundice.
There are three types of jaundice.
Haemolytic jaundice
Obstructive jaundice
Toxic jaundice.
Diarrhoea
It is a condition characterised by an abnormally frequent discharge of watery stools from the bowel.
The primary cause of diarrhoea is high intestinal motility.
Other causes of diarrhoea are:
Infection
Allergy
Dietic toxemia.
Dysentery
This disease is marked by evacuation of a frequent watery stools often with blood and mucus.
Constipation
Constipation is a condition in which defaecation is delayed and hard stools are formed due to reabsorption of large amount of water from intestinal contents.
Cirrhosis of Liver
It is a disease related to liver in which hepatic cells are damaged. It may be due to excessive alcohol consumption as well as some secondary infections.
Tonsilitis
It is inflammation of tonsils (adenoids) lymphoid tissue present in the pharynx.
The Skeletal Muscles
1 Define muscle. Classify/give types of muscular tissue.
Muscle
Muscle is a powerful tissue which contains numerous fibres which are responsible for all movements of the body.
Classification of Muscles
Voluntary muscles/skeletal muscles/striated muscles, e.g. found attached to skeleton.
Involuntary muscles/unstriated muscles/smooth muscles,
e.g. muscles of stomach and intestine.
Cardiac muscles, e.g. found in myocardium of heart.
2 Functions of muscles/muscular tissue.
1. Muscles play an important role in locomotion of the body.
Muscles make changes in posture (position) of the body,
e.g. standing, lying down, sitting.
Muscle performs the function of production of heat.
Muscle helps to maintain fluid balance.
Muscle forms walls or body cavities and supports the organs within the cavities.
Muscles give shape to the body.
Muscles provide protection to underlying tissues of the body.
Muscles maintain circulation of blood by forceful contraction of heart, e.g. cardiac muscles.
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Muscles help in respiration and maintain acid–base balance of the body, e.g. intercostal muscles and diaphragm.
The muscles are the agents of brain by means of which we attend (show) the expression and feeling.
3 Define skeletal muscle. Explain the structure and give functions of skeletal muscles.
Skeletal Muscle
The voluntary muscles which are attached to the skeleton are called skeletal muscles.
They are also called striated or stripped muscles. They work under the control of will power and hence called voluntary muscles. The muscle fibres lie in the skeleton, hence called skeletal muscles.
Skeletal muscle fibres are roughly cylindrical shaped.
There are small bundles of fibres enclosed in the perimycium.
Each fibre attached to the fibrous tissue is called endomycium.
Sarcolemma is a fine sheath surrounding each fibre.
Each fibre shows a nucleus and sarcoplasm. They lie parallel to each other and show transverse light and dark bands alternately.
Functions of Skeletal Muscle
To contract and provide the movement to the body according to stimulus.
It helps in thermogenesis.
It gives shape to the body.
It maintains fluid balance in the body.
4 Explain various properties/characteristics of skeletal muscle.
Properties of Skeletal Muscle
Muscle tone: Muscle is never in completely relaxed condition/in resting position but it is always in the state of partial contraction. This is known as muscle tone.
Muscle tone in the skeletal muscle is responsible for maintaining posture of the body.
Muscle fatigue: If a muscle is stimulated frequently to contract, its response to stimulus is progressively decreases. Finally, it may not contract by stimulation. Such a condition is called muscle fatigue.
Underlying cause of muscle fatigue:
Constant stimulation of muscle or contraction.
Inadequate blood supply to the muscle.
Refractory period: After stimulation, their is a brief period during which muscle is not excitable to second stimulus, this is known as refractory period.
Muscle contraction: By adequate stimulus, muscles are excitable. When muscles are excited they give contractility and this is immediately followed by relaxation.
Extensibility and elasticity: The skeletal muscle extends when stretched. When tension on the muscle is released, it goes back to original position. This is known as elasticity of the muscle.
Conductivity: After stimulation, wave of contraction starts at a point of stimulus and is conducted along the muscle fibre.
5 Name the muscles of facial expressions.
Muscles of Facial Expression
Orbicularis: Circular muscle surrounding each eye.
Oculi: Muscles close to tip.
Levator; palpebrae superiors to raise the eyelids.
Massetor: Muscles for mastication.
Buccinator: Flat muscles of neck.
6 What is neuromuscular junction? Explain physiology of neuromuscular junction (muscle contraction).
Neuromuscular Junction
Neuromuscular junction is a connection between ends of large myelinated nerve fibre and skeletal muscle fibre.
Structure of Neuromuscular Junction
Physiology of Neuromuscular Junction/Muscle Contraction
When a nerve impulse reaches the neuromuscular junction, the passage of action potential over sole feet causes many of small vesicles of acetylcholine to rupture into synaptic cleft.
Acetylcholine acts on plasma membrane to increase its permeability. This in turn allows spontaneous leakage of sodium causing end plate potential.
When end plate potential becomes great enough, it stimulates entire muscle fibre.
When action potential spreads inside of muscle fibre, Ca2+ ions are released into the fluid surrounding the fibres. Thus, due to release of Ca2+, muscle contraction takes place.
Immediately after release of Ca2+, there is a muscle contraction.
When action potential is over, previously released Ca2+ ions recombine with sarcoplasmic reticulum and muscle contraction ceases (stops).
7 Distinguish between skeletal muscle and smooth muscle.
Skeletal muscle
Smooth muscle
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
It is described as voluntary or stripped.
These are found attached with skeleton.
It works under the control of will.
The cells are rough, cylindrical in shape with several nuclei.
Conductivity is very fast.
Tonicity depends upon nerve stimulation.
Percentage of proteins is maximum in skeletal muscle.
It works under the control of CNS.
It is described as involuntary or visceral muscles.
These are found in the walls of blood vessels, alveoli of lung and respiratory canal.
It does not work under the control of will.
The cells are spindle-shaped with only one central nucleus.
Conductivity is slower.
Tonicity is not dependent on nerve stimulation.
Percentage of proteins is less.
It works under the control of ANS.
8 What are ‘biceps’ and ‘triceps’ muscles? Give their functions.
Biceps
Biceps is a two-headed muscle that lies on the upper arm between the shoulder and the elbow anteriorly.
Function: It stabilises and flexes the shoulder joint and at the elbow joint it assists with flexion and supination.
Triceps
The triceps run along the humerus between the shoulder and the elbow located posteriorly.
Function: Along the biceps, it enables extension and retraction of the forearm. It also stabilises the shoulder joint.
The Nervous System
The nervous system is most important organisation which controls and regulates different body functions and maintains stability of internal environment with respect to extreme changes in external environment.
1 Differentiate between CNS and ANS.
CNS
ANS
(i)
(ii)
(iii)
(iv)
(v)
It consists of brain and spinal cord.
It is related with sensory and motor activity of brain.
It enables the person to adjust with external environment.
The functions of CNS occur according to will power.
It supplies the nerves to skeletal muscles (motor nerve) and sensory nerve carries impulses from sense organs to the brain.
It consists of sympathetic and parasympathetic nerves.
It is related with the activity of heart, various glands and smooth muscles.
It enables the person to adjust with internal environment of the body.
The functions of ANS do not occur according to will power.
It supplies the nerve to smooth muscles of visceral organs such as ureters, uterine tubes, bronchi, trachea, heart, etc.
2 What are meninges? Explain coverings of brain and spinal cord.
Meninges
Meninges are the connective tissue membranes which cover and protect different parts of ‘CNS’.
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There are three meninges.
Dura mater: It is an outer, thick, fibrous membrane which gives covering to the brain and spinal cord. The space between dura mater and arachnoid mater is called subdural space.
Arachnoid mater: It is the middle, delicate, thin, vascular membrane situated between dura mater and pia mater. The space between arachnoid mater and pia mater is known as subarachnoid space. The subdural space and subarachnoid space contain a fluid known as cerebrospinal fluid (CSF) which acts as a shock absorber.
Pia mater: It is the innermost, fine, vascular membrane consisting mainly of blood vessels supported by fine connective tissue.
Functions of Meninges
To protect and support the brain and spinal cord.
To supply the blood and nourishment to the central nervous tissue.
3 What is CSF? Give the composition and functions of cerebrospinal fluid.
CSF
It is a clear watery fluid present in the space between meninges of the brain and spinal cord and is secreted by choroid plexus.
Composition of CSF
Water
Amino acid
Glucose
Mineral salts
Urea and creatinine in small amounts
Plasma proteins, i.e. small amounts of albumin and globulin.
Functions of CSF
It acts as a cushion and shock absorber.
It maintains uniform pressure around the delicate structures of CNS.
It supports and protects the delicate structures of brain and spinal cord.
It keeps the brain and spinal cord always moist.
It acts as a medium for the movement of respiratory gases, waste products and nutrients.
4 Sketch and label a diagram of brain.
Brain
5 Describe the structure and mention the functions of cerebrum.
• Cerebrum is the largest part of the brain and is divided into two equal parts by central longitudinal fissure.
These two hemispheres are internally connected by a mass of white matter called corpus callosum.
Each hemisphere is divided into four lobes, namely frontal lobe, parietal lobe, temporal lobe and occipital lobe.
Each lobe is separated from another by a sulcus or a fissure.
The central sulcus separates frontal and parietal lobes.
The lateral sulcus separates frontal and parietal lobes from temporal lobe.
The parieto-occipital sulcus separates parietal lobe from occipital lobe.
The outer surface of cerebrum is made up of gray matter and inner side is made up of white matter.
The gray matter is composed of thalamus and hypothalamus.
Functions of Cerebrum
Sensory function: It includes perception of pain, temperature, touch and special senses are sight, hearing, taste, smell from sensory organs which are carried to the cerebrum.
Motor function: It is associated with initiation and control of contraction of voluntary muscles.
Association: It includes mental activities like intelligence, sense of responsibility, reasoning, learning which are attributed to higher centres in the cerebrum.
6 Draw and label a diagram showing functional areas of cerebrum.
Premotor area Taste area
Motor speech area
Motor area
Central sulcus
Sensory area
Speech sensory area
Visual area
Auditory area
The cerebrum showing the functional areas
7 Give the functions of medulla oblongata.
Medulla Oblongata
It forms the base of the brain and connects brain with spinal cord.
Functions of Medulla Oblongata
The cardiac centre present in the medulla oblongata controls heart rate and force of contraction of heart.
The respiratory centre present in medulla oblongata controls rate and depth of respiration.
The vasomotor centre in the medulla oblongata controls calibre of blood vessels and maintains normal blood pressure.
The reflex centre present in the medulla oblongata protects from entry of harmful substances into the body.
8 Mention the functions of cerebellum.
Functions of Cerebellum
It controls and coordinates the activities of various groups of muscles ensuring smooth actions.
It maintains muscle tone.
It coordinates activities associated with maintenance of balance of the body and equilibrium of the body.
9 Draw and label a diagram of TS of spinal cord.
TS of spinal cord
Define spinal cord. Give the functions of spinal cord.
Spinal Cord
Spinal cord is an elongated and almost cylindrical part of the CNS and extends from medulla oblongata.
It is about 45 cm long and is about thickness of little finger. Spinal cord is surrounded by dura mater, arachnoid and pia maters.
The spinal cord emerges out from an opening in the cranium known as foramen magnum.
Functions of Spinal Cord
It gives connection between peripheral organs and brain.
It acts as a main centre for various reflex actions.
It acts as a connecting link between brain and spinal nerves.
What is reflex action? Explain components of simple reflex arc.
Reflex Action
The automatic and rapid response to sensory stimulus without involvement of brain is called reflex action.
Simple reflex arc: The path through which impulse travels during reflex action is called simple reflex arc.
Structure of Simple Reflex Arc
Receptor
organ
Effector organ
Sensory nerve
Mixed nerve
Motor nerve
Posterior root ganglion
Spinal cord
Gray matter White matter
Connector neuron
Components/Parts of Simple Reflex Arc
Receptor organ: It is the part where stimulus is received.
Sensory neuron: It is the nerve cell which carries nerve impulse from sense organ to spinal cord.
Connector neuron: It converts sensory impulse into motor impulse.
Motor neuron: It conducts nerve impulses from spinal cord to effector organs.
Synapse: The space between two neurons is called synapse.
Effector organ: It is the part of body which gives response.
Significance/Importance of Reflex Action
It gives quick responses and protects the body from any harm or danger.
It prevents overloading of brain and gives relief of pain.
The reflex action helps the person to adjust with changing environment.
Examples of Reflex Actions of the Body
Quick closing of the eyelid if eye is touched or something threatens to touch the eye.
The sudden withdrawal of hand if finger is touched with hot object.
Quick recovery of the balance of the body to prevent falling after asleep.
A sudden coughing attack, if any irritating substance is inhaled.
In infants, the act of micturition and defaecation is carried out reflexly.
12
Name different cranial nerves with their functions.
Cranial Nerves
The nerves which arise from the brain are known as the cranial nerves.
There are 12 pairs of cranial nerves which are arranged in the following sequence:
Nerve
Type
Functions
(i)
Olfactory nerve
Sensory
Smell
(ii)
Optic nerve
Sensory
Vision
(iii)
Oculomotor nerve
Motor
Eyeball movement
Contd...
Nerve
Type
Functions
(iv)
Trochlear nerve
Motor
Eyeball movement
(v)
Trigeminal nerve (largest)
Mixed
Head, face muscle movements
(vi)
Abducent nerve
Motor
Eyeball movements
(vii)
Facial nerve
Mixed
Taste, salivation, tear secretion
(viii)
Auditory nerve
Sensory
Hearing
(ix)
Glossopharyngeal nerve
Mixed
Swallowing
(x)
Vagus nerves
Mixed
Gastric, pancreatic secretion
(xi)
Accessory nerves
Motor
Neck and shoulder muscle movement
(xii)
Hypoglossal nerve
Motor
Tongue movement
13
Explain the physiology of ANS/effect of stimulation of SNS and PSNS. OR What will be the effect of stimulation of sympathetic and parasympathetic nervous systems on the following organs?
Organ
Sympathetic stimulation
Parasympathetic stimulation
(i)
Heart
Increases heart rate
Decreases heart rate
(ii)
Myocardium
Increases myocardial contractility
Decreases myocardial contractility
(iii)
Lungs (bronchi)
Bronchodilation
Bronchoconstriction
(iv)
GIT motility
Decreases GIT motility
Increases GIT motility
(v)
Pupils of eye
Dilation of pupils
Constriction of pupils
(vi)
Urinary bladder
Relaxation of smooth muscles of urinary bladder
Increased contraction of urinary bladder
Contd...
Organ
Sympathetic stimulation
Parasympathetic stimulation
(vii)
Glandular secretions (exocrine)
Decreased secretions of exocrine glands
Increased secretions of exocrine glands
(viii)
Blood vessels
Constriction of blood vessels
Dilation of blood vessels
(ix)
BP
Increases BP
Decreases BP
(x)
Cardiac output
Increases cardiac output
Decreases cardiac output
14
Give comparison/difference between.
Sympathetic nervous system (SNS)
Parasympathetic nervous system (PSNS)
(i)
It is the thoracolumbar system.
It is the craniosacral system.
(ii)
Sympathetic trunk ganglia and collateral ganglia are present.
Parasympathetic ganglia are present.
(iii)
Ganglia are close to the CNS and distant from visceral effectors.
Ganglia are near or within the wall of visceral effectors.
(iv)
The preganglionic nerve fibres are smaller.
The preganglionic nerve fibres are longer.
(v)
The postganglionic nerve fibre is larger.
The postganglionic nerve fibre is smaller.
(vi)
The preganglionic neurotransmitter is adrenaline.
The preganglionic neurotransmitter is acetylcholine.
(vii)
The targeted receptors are mostly adrenergic.
The targeted receptors are mostly cholinergic.
(viii)
Distributed throughout the body.
Distribution is limited particularly to head and viscera of thorax, abdomen and pelvis.
(ix)
It is also known as adrenergic nervous system.
It is also known as cholinergic nervous system.
Contd...
Sympathetic nervous system (SNS)
Parasympathetic nervous system (PSNS)
(x)
It has alfa and beta receptors.
It has muscarinic and nico-tinic receptors.
(xi)
It is involved in expenditure of energy.
It deals with restoration of body energy.
15 Give the functions of hypothalamus.
Functions of hypothalamus
It controls autonomic nervous system.
It controls appetite.
It regulates thirst.
It maintains emotional behaviour, personality and social behaviour.
It regulates body temperature.
It regulates and controls release of hormones from pituitary gland.
It controls sexual behaviour.
The Sense Organs
1 State different senses along with the organs.
There are five different senses
Sense of taste Tongue
Sense of touch Skin
Sense of vision (sight) Eye
Sense of hearing Ear
Sense of smell Nose
2 What are different papillae of tongue? Mention the functions of tongue.
Tongue
Tongue is organ of sensation of taste.
There are numerous papillae present in the tongue.
The tongue is a very mobile organ and is covered by mucus membrane.
The roughness of upper surface of tongue is due to numerous minute elevations, are called papillae.
The end organs of the sense of taste are called taste buds.
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There are three types of papillae found in the area of tongue.
Papillae of tongue
Vallate papillae: They form an inverted ‘V’ shape at the base.
Fungiform papillae: These are situated on the sides and at the tip of the tongue.
Filiform papillae: These are found mainly on the anterior two-thirds of the tongue.
Functions of Tongue
Tongue is an organ of sensation of taste.
It helps in mixing of food during mastication.
It also helps in swallowing of food.
It plays an important role in speech.
It is also sensitive to temperature, pain, touch and pressure.
3 What are different fundamental sensations of the taste?
There are four fundamental sensations of taste.
Sweet
Sour
Bitter
Salty
The substances stimulate taste buds in specific parts of the tongue.
Tongue showing taste areas
Sweet and salty tastes—at the tip of the tongue.
Sour—at the sides of the tongue.
Bitter—at the back of the tongue.
4 What are taste buds? Explain the physiology of taste.
Taste Buds
The tongue contains taste buds. The end organs of the taste are called taste buds.
Taste buds contain chemoreceptor’s (sensory receptors) that are found in the papillae of the tongue and widely distributed in the epithelia of the tongue.
The taste buds consist of collection of sensory receptor and supporting cells together with sensory nerve ending.
They consist of small sensory nerve endings of the glossopharyngeal, facial and vagus nerves.
Some of the tastes cells have hair-like cilia on their free border, projecting towards tiny pores in the epithelium, are known as taste hairs.
Physiology of Taste
TS of taste bud
There are four fundamental sensations of the taste like sweet, sour, bitter, and salty.
The sensory receptors are highly sensitive and stimulated by very small amount of chemicals that enter the pores dissolved in saliva.
The substances in solution enter the pores of the taste buds and stimulate the hair-like endings of the cells.
Nerve impulses are generated and conducted along the glossopharyngeal, facial and vagus nerves before reaching in the medulla and thalamus.
The impulses are transmitted to the thalamus and then to the taste area in the cerebral cortex where taste is perceived.
5 Sketch and label a diagram of LS/VS of skin.
LS/VS of skin
6 Mention two layers of the skin.
Skin
Epidermis (outer layer) Dermis (inner layer)
Keratinizing zone (i) Blood vessels
Stratum corneum (ii) Nerve ending of sensory nerve
Stratum lucidum (iii) Sweat glands
Stratum granulosum (iv) Sebaceous glands
Germinative zone (v) Hair follicle
Prickle cell layer (vi) Apocrine glands
Basal cell layer (vii) Nails
7 Describe the epidermis/outer layer of the skin.
Epidermis
It is an outer layer of the skin also known as superficial layer.
Epidermis is composed of stratified epithelium consisting of number of cell layers arranged in two zones.
Keratinizing zone (horny zone): This is a superficial layer consisting of three upper layers.
Stratum corneum: The cells of this layer are thin, flat and scale like structures. These are non-ciliated and protoplasm of these cells is replaced by horny substance called keratin.
Stratum lucidum: It contains clear protoplasm and some of the cells contain nuclei.
Stratum granulosum: The cells of this layer contain nuclei and granules.
Germinative zone: It consists of two layers of epithelial cells as prickle cell layer and basal cell layer.
Prickle cell layer holds the cells together.
The basal cell layer:
🞍 The basal cells are arranged in wave like order. They are packed closed together and form the layer of cells, which rest on papillae of the dermis.
🞍 These cells reproduce rapidly and replace the cells from superficial layer.
🞍 Between the cells of basal layer, melanocyte layer is present which contains melanoblast cells.
🞍 Melanoblast cells contain skin pigment ‘melanin’ which gives colour to the skin.
The epidermis does not contain any blood vessel but the cells of epidermis are bathed in a fluid called a lymph which is collected by different lymphatic vessels.
Functions of Epidermis
It covers and protects internal tissues.
It prevents entry of microorganisms into the body.
It gives support to the hair shaft.
It helps in regulation of body temperature.
8 Explain dermis layer/innermost layer of the skin.
Dermis: It is an innermost/deepest layer of the skin. The dermis or corium is composed of dense, fibrous and elastic connective tissue.
There are many structures distributed in the dermis layer.
Blood vessels: The circulation of blood through the dermis layer gives nourishment to the skin and plays an important role in the regulation of body temperature. Dermis contains an extensive network of blood capillaries in the subcutaneous layer. Dermis has a rich network of lymphatic vessels.
Nerves: The skin provides the body’s sensory information and is provided with between sensory nerves and sympathetic nerve fibres. Sympathetic nerve fibres are supplied to the vessels, the smooth muscle of the hair follicle and the secretary cells of the sweat glands.
Sweat glands: These are found in the skin all over the body, but are mostly present in the palms of the hand, soles of the feet, and on the forehead. Each gland consists of a tube coiled up into a ball present in the dermis and opens on the outer surface of the skin as a sweat pore.
Functions
It helps in excretion of sweat.
It helps to regulate body temperature by heat loss through the sweat.
Sebaceous glands: These are found mostly in the skin of the face, scalp and all hairy parts of the body. Sebaceous glands secrete an oily secretion called sebum.
Functions:
The sebum keeps the skin smooth, soft and gives shiny appearance to the hairs.
The sebum prevents drying and cracking of the skin.
The sebum protects the damage of skin by the exposure of heat and sunshine.
Hair follicle:
Each hair consists of a free shaft, extending above the skin surface and a root embedded in the skin.
The hair root is enclosed in a hair follicle. The lower end of the follicle expands to form the hair-bulb.
At the end of hair bulb, there is a small projection of cells derived from the dermis called the papilla.
The papilla contains blood vessels, nerve endings and melanocytes.
9 Mention the functions of skin.
1. It protects deeper delicate organs of the body from injury and infection.
Skin contains end organs of sensory nerves.
The skin absorbs oily substances and drugs.
It gives origin to hairs and nails.
Skin secretes oily secretion, i.e. sebum from sebaceous gland which keeps the skin soft, smooth and gives shiny appearance to the hairs.
Skin helps in excretion of waste materials such as fatty material and water in the form of sweat by sweat glands.
Skin contains 7-dehydrocholesterol which is converted into vitamin D by the action of sunlight.
Skin gives protection against ultraviolet radiations.
Skin and subcutaneous tissue act as storage of water and fats.
Skin plays an important role in the regulation of body temperature.
Write in brief about sweat gland and sebaceous gland.
(a) Sweat Glands
These are mostly present on the forehead, maxilla, parts of nose, and axilla. These consist of a tube originating from dermis and open on the surface by an opening called a sweat pore. These glands secrete sweat.
Sweat
Sweat is a clear watery fluid containing 0.5% of solids and is secreted by sweat glands.
Composition of Sweat
Water
Sodium chloride (salt)
Small amount of other mineral salts
Urea in small amount.
Functions of Sweat Glands
They help in excretion of water and salty material.
Sweat gland regulates body temperature by heat loss through the sweat.
Sebaceous Glands
These glands are mostly found on forehead, sides of the nose and parts of ear. These glands secrete sebum.
Sebum
Sebum is an oily substance secreted by sebaceous glands that keeps the hair soft and pliable and gives shiny appearance to the hairs.
Functions of Sebaceous Glands
The sebum provides some waterproofing and acts as a bactericidal and fungicidal agent preventing the entry of microbes into the body.
The sebum keeps the skin smooth, soft and gives shiny appearance to the hairs.
The sebum prevents drying and cracking of the skin.
The sebum protects the damage of the skin by the exposure of heat and sunshine.
Explain how skin helps in regulation of body temperature?
Skin regulates the body temperature by the following mechanism.
Man is a cold-blooded animal and is capable of maintaining a relatively constant central body temperature which is independent of the surrounding environment.
The constant level of the body temperature is maintained by a balance between the heat produced and heat loss by the body.
Heat production:
All the body tissues produce heat from chemical process of metabolism, but the greatest heat production is from the most active tissues such as liver, endocrine glands and muscles.
Muscular activity accounts for about 30% of body’s heat production at resting position.
Heat may also be gained (increased) by the body when environmental temperature exceeds body temperature.
Heat loss:
Heat is lost from the body through the skin by radiation, conduction, convection and evaporation.
A small amount of heat is lost in expired air, urine and faeces.
Explanation
Body temperature is controlled by the temperature-regulating centres of the hypothalamus.
These contain two groups of neurons:
Heat sensitive neurons
Cold sensitive neurons
A fall in body temperature causes the temperature-regulating centres to conserve heat by increasing sympathetic nerve impulses, resulting in constriction of cutaneous blood vessels and stimulates heat production by shivering (involuntary shaking of body).
A rise in body temperature causes the temperature-regulating centres to inhibit sympathetic nerve impulses to cutaneous blood vessels resulting in dilation of blood vessels and increased blood flow through the skin. Sweat glands stimulated to secrete sweat which is evaporated from the skin surface with consequent loss of heat and body temperature achieves normal level.
Schematic Presentation of Regulation of Body Temperature
Sketch and label a diagram of section of eye/ saggital section of eye.
Name different layers/coverings/coats of the eye. OR State various parts of the eye.
• Eye is the organ of vision/sight.
There are two eyeballs situated in the bony sockets
called orbits.
Eyes are also called ‘photoreceptors’.
The structure of eye may be considered in the following way:
Explain an outermost layer/coat/covering of the eye.
Sclera
It is an outermost layer of tissue of the eyeball which is referred as ‘white of eye’.
Over exposed part of eyeball there is a superficial mucus membrane called ‘conjunctiva’ which is also reflected along the inner surface of the eyelids.
Functions of Sclera
To maintain shape of eyeball.
To protect inner layer of eye.
To provide a surface for attachment of extrinsic eye muscles.
Cornea
Cornea is an anterior extension of sclera.
Cornea is also sometimes called ‘window of eye’.
Cornea is transparent epithelial membrane slightly curved or convex.
Cornea has no blood vessels but it is nourished from aqueous humour.
Function of Cornea
It allows the light to enter the interior of the eye because of transparent nature.
Explain middle layer/coat/covering of the eye?
The middle layer of eye contains many blood vessels and capillaries, which are derived from the ophthalmic branch of the internal carotid artery and is pigmented.
The middle layer consists of following structures:
The Choroid
The choroid is a thin pigmented membrane dark brown in colour, which lines the posterior component of the eye.
It is situated in between the inner surface of the sclera and the retina.
Function: It helps in absorption of extra light entering in the eyeball.
Ciliary body
It is an anterior continuation of choroid slightly curved inside. It consists of the ciliary muscle and epithelial cells.
Functions
To give suspensory ligaments suspending the lens.
It helps in contraction and relaxation of ciliary muscles.
It helps to change the thickness of the lens.
The epithelial cells of the ciliary body secrete aqueous and vitreous humour.
Iris
Iris is a circular body and is an anterior extension of the ciliary body present behind the cornea.
Iris is a pigmented membrane which surrounds the pupil of eye.
Iris is attached to the ciliary process and is present between cornea and the lens.
It consists of radiating and circular muscles along with pigment cells.
The central aperture of the iris is known as pupil of eye.
The colour of eye is dependent on the pigment present in the iris.
Functions
It regulates the amount of light entering the posterior part of the eye.
It helps to control the size of the pupil.
The muscles of iris contract and relax causing dilation and constriction of pupil.
Pupil
The central aperture of the iris is known as pupil.
The pupil varies depending upon the intensity of light.
In dim light, the radiating muscle fibres contract and produce dilation of pupils.
Function: The pupil helps to control the amount of light entering the iris.
Describe innermost layer/coat of the eye. OR Describe the retina of the eye.
Retina
Retina is the innermost layer of the eye.
Retina is delicate membrane consisting of nerve cells, nerve fibres, rods and cones.
The rods and cones are the actual receptors of sight and light reaching them sets up the impulses which are transmitted to the nerves.
The impulses are generated by the action of light on the photosensitive pigment in the rod cells is known as ‘rhodopsin’.
The cones are responsible for colour vision.
The retina is purple coloured due to rhodopsin pigment present in the rods.
The point at which optic nerve emerges out contains no nerve cells, no rods and cone cells. Therefore, it is insensitive to light and is called ‘blind spot’.
Opposite to the lens there is a yellow spot known as ‘macula’ with only one cone for image focusing.
Macula is a small area of retina of great sensitivity on which the images are seen directly.
Functions
The retina contains rod cells which have ‘rhodopsin’ pigment, is responsible for generation and transmission of impulses.
The cones are responsible for colour vision.
Write in brief and mention the functions of the following.
(a) The Aqueous Humour
The fluid present in the anterior chamber of the eye is called aqueous humour.
Aqueous humour is situated in between cornea, iris and the ciliary body.
Aqueous humour is secreted by ciliary muscles.
Functions
It keeps the parts of eye moist.
It gives nourishment to the cornea.
The Lens
The lens is an elastic, circular, biconvex, transparent body present behind the pupil.
It is made up of protein fibres and suspended by ligaments.
The thickness of lens is controlled by ciliary muscles.
Function: The lens help to focus the rays of light entering the eye through the pupil on the retina.
The Vitreous Body
It is a colourless, transparent jelly-like substance which fills the posterior four-fifths of the eye.
The substance present in the vitreous body is known as vitreous humour.
Function: The vitreous humour helps to preserve the spherical shape of the eyeball and to support the retina.
Sketch and label a diagram of ear.
Diagram of ear
Mention various parts of the ear.
Describe in brief about external ear.
External Ear
External ear helps to collect the sound waves. It consists of:
Pinna, (b) external acoustic meatus.
Pinna (Auricle)
It is irregular in shape and is composed of cartilage and fibrous tissue.
Pinna is deeply grooved and ridged. The most prominent
outer ridge is the helix.
The lobule is soft pliable part present at the lower end and it is composed of fibrous and adipose tissue richly supplied with blood capillaries.
External Acoustic Meatus (External Auditory Canal)
It is slightly ‘S’-shaped tube about 2.5 cm long extending from the auricle to the tympanic membrane.
The meatus or canal is lined by numerous ceruminus glands.
The ceruminus glands are modified sweat glands. They secrete cerumen (wax) which is sticky material.
The presence of wax, hairs and curvature of the meatus prevents dust, insects and microbes from reaching the tympanic membrane.
What are auditory ossicles (ear ossicles)? Mention the functions of auditory ossicles.
Auditory Ossicles
Auditory ossicles are three small bones that extend across the cavity from tympanic membrane to oval window in the middle ear.
Auditory ossicles form a series of movable joints with each other and with medial wall of the cavity at the oval window.
Auditory ossicles are, namely malleus, incus, and stapes.
Malleus: It is a lateral hammer-shaped bone. The handle is in contact with tympanic membrane and the head forms a movable joint with incus.
Incus: It is the middle anvil-shaped bone. Its body articulates with malleus and long process articulates with stapes.
Stapes: It is a medial stirr-up shaped bone. Its head articulates with incus and its base fits into oval window.
Functions of Auditory Ossicles
The auditory ossicles collect the sound waves from eardrum and are modified due to freely movable joints present in it.
They help to transmit the vibrations of sound from eardrum to the internal ear.
Describe the structure of internal ear.
Internal Ear
It consists of several cavities which channel the temporal bone.
These cavities are called the outer bony labyrinth and inside which is the membranous labyrinth.
The cavities contain fluid and nerve endings for hearing and balance.
The bony labyrinth contains a fluid called ‘perilymph’.
Bony Labyrinth
The bony labyrinth consists of three parts.
Vestibule (1): It is an expanded part nearest to the middle ear.
Cochlea (organ of hearing) (1): It is a spiral tube twisted on itself resembling a small snails shell. It has a broad base where it is continuous with vestibule. The coils are arranged around a central bony cone-shaped axis called modiolus.
Semicircular canals (3): These are three tubes arranged in superior, posterior and lateral positions. Each canal has swelling at one end called ampulla. These canals are filled with the fluid called perilymph which assists the cerebellum to maintain the equilibrium and sense of position of the body.
Membranous Labyrinth
It is present within the bony labyrinth. It is filled with a fluid called ‘endolymph’.
Functions of Internal Ear
The vibrations from the middle ear are transferred to the perilymph which is then transmitted to endolymph, stimulating the nerve ending of the auditory nerve.
The auditory nerve finally conveys the information to the cerebral cortex.
The vestibular nerve distributed to the semicircular canal conveys the information to the brain.
Explain mechanism/process/physiology of hearing.
Mechanism of hearing
The sound waves collected by pinna pass through various parts of ear towards auditory nerve and then are passed to the brain at the auditory centre.
The following are sequence of events shows mechanism of hearing:
Sound waves Pinna (auricle) External acoustic meatus (auditory canal) Eardrum (tympanic membrane) Malleus Incus Stapes Vestibule Cochlea (perilymph endolymph)
Organ of Corti 8th cranial nerve (auditory nerve)
Temporal lobe of brain.
Explanation
Sound waves collected by pinna are directed in external auditory canal to reach the tympanic membrane. Sound waves strike the tympanic membrane.
The vibrations are transmitted by malleus, incus, stapes to the membrane covering fenestra vestibule (vestibule).
From the inner surface, this membrane vibrations are transmitted towards cochlea and semicircular canals and finally to organ of Corti, i.e. vibrations are transmitted from perilymph to endolymph.
From the organ of Corti (present in the endolymph), the impulses produced by vibrations are carried to the brain through the cochlea portion of auditory nerve.
The nerve fibres then carry the impulses to the auditory centre of the brain which is present in the temporal lobe of the cerebral cortex where interpretation of sound impulses takes place.
In this way, process of hearing takes place.
Describe the structure of nose. Mention the functions of nose.
Nose: Nose is an organ of respiratory system as well as an organ of sensation of smell.
Structure of Nose
The nasal cavity is the first part of respiratory system and consists of a large irregular cavity divided into two equal parts by a septum situated in the midline.
Explanation
The nose is lined with ciliated columnar epithelium which contains mucus secreting goblet cells.
Olfactory nerves are the sensory nerves of the smell.
Olfactory nerves have their origin in special cells in the mucus membrane of the roof of the nose and the superior nasal concha.
Nerve fibres from the cells are gathered into bundles then pass through the cribriform plate of the ethmoid bone to the olfactory bulb.
From the bulb, bundles of nerve fibres form the olfactory tract which passes backwards to the olfactory area in the temporal bone of the cerebral cortex in each hemisphere where the impulses are interpreted.
Functions of Nose
Nose is the first part of respiratory system through which the incoming air passes.
The air is warmed, moistened and filtered in the nose.
The cilia of the mucus membrane of the nose help to carry the mucus towards the throat and then it is swallowed.
It is an organ of sensation of smell.
Explain the terms.
1. Myopia
It is a short sightedness. It is caused due to defect in accommodation of eye. Person can see near objects distinctly but distant objects are seen with difficulty. The image falls short of reaching the retina and person experiences ‘blurred image’.
Diplopia
It means appearance of double vision.
Presbiopia
It is the disorder of eye in which there is an improper functioning of ciliary body.
Here, the image of an object is formed in front of the retina. Thus, distant objects are seen clearly but near objects are not in focus properly. This is caused due to loss of elasticity of the lens and lack of tone of ciliary body. It is the disorder of vision for farthest distant objects due to formation of image in front of the retina. It is due to the defect in the lens.
Hypermetropia
It is the disorder of eye causing falling of an image of an object behind the retina due to flattened cornea or lens or shallow eyeballs. This causes difficulty in vision of near distant, i.e. foresightedness.
The distant objects can be seen but the near objects cannot be seen.
Cataract
It means thickening of fibrosis of the lens. It is due to nutritional deficiency of sulphur containing amino acids, i.e. cysteine, methionine.
Colour Blindness
It is the defect of retina in which the person cannot see more than one colour.
Night Blindness
It is caused due to deficiency of vitamin A. It is characterized by absence of defective vision in the dark.
Photophobia
It is an abnormal sensitiveness of the eye to the bright light.
Xerophthalmia
It means extreme dryness of conjunctiva which loses its luster and becomes skin-like appearance due to lack of intrinsic secretions.
Glaucoma
It is the condition where intraocular pressure or tension is increased.
It is the disease caused due to failure of drainage of liquid from the anterior chamber as a result of which more than required amount of liquid accumulates in it and causes pressure on the optic nerve and retina.
Scabies
It is an infectious parasitic disease of skin characterized by itching and superficial burrows on the skin.
The Urinary System
The main function of urinary system is formation and excretion of urine from the body.
1 Draw and label a diagram of urinary system/excretory system/renal system.
Urinary system
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2 Explain the structure of kidney. Mention functions of kidneys.
Structure of Kidney
Renal capsule
Renal cortex
Renal medulla
Pyramids Calyces
Pelvis of ureter
Ureter
Renal column
LS of kidney
Kidneys are two in number. Each kidney is bean-shaped and reddish brown in colour.
Kidneys are about 10 cm in length and 5 cm in breadth.
In an adult each kidney weights about 140 g.
Section:
Each kidney is enclosed in a capsule of fibrous connective tissue called renal capsule.
Outer granular dark zone is renal cortex and inner zone is renal medulla.
The medulla is divided into conical projections called renal pyramids.
The pelvis at its free ends produces many cup-shaped projections called renal calyces.
The renal vein and artery arise from the kidney through hilum region.
The kidney contains closely packed microscopic structures known as nephrons.
Nephrons are the structural and functional units of kidneys.
Functions of Kidney
It helps in formation of urine.
It regulates water and electrolyte balance.
It maintains blood pressure.
It maintains composition of blood constant.
It removes excess of foreign substances such as drugs, pigments, etc. from the body.
It maintains total water balance of the body.
3 Write in brief about urinary bladder and urethra.
(a) Urinary Bladder
It is a large muscular pear-shaped sac present in the pelvic cavity.
The walls of urinary bladder are lined by smooth muscles.
The urinary bladder stores about 0.5 to 1 litre of urine temporarily.
Functions
It acts as a temporary storage of urine.
It expels the urine by the contraction of smooth muscles present in it.
Micturition is an important function of urinary bladder. Micturition: Means an act of emptying the urinary bladder by contraction of smooth muscles present in it.
It acts as a reservoir for water to prevent dehydration under the conditions of dryness.
Urethra
It is a tube-like structure arising from the urinary bladder.
Urethra in case of male and female shows different structures.
In male: In males, the urethra extends up to the tip of the penis and acts as a common passage for both sperms and urine.
In female: In female, the urethra is short tube opening separately just in front of the vagina. Urethra in female carries only urine.
Functions
The urethra is the last part of urinary system and helps in expelling the urine outside the body.
4 Explain, how kidney helps in water balance of the body?
Water constitutes about 60% of adult human body weight. The balance between fluid intake and output is controlled by kidneys. Thus, kidney helps to maintain water balance by ADH mechanism or urine output mechanism.
Water in the body is less
Osmotic pressure of blood is reduced
Osmoreceptors of hypothalamus are stimulated
Stimulates posterior lobe of pituitary gland
Stimulates secretion of ADH
Increases the reabsorption of water
Increases water level in the body
Effect of ADH is inhibited
Explanation
When amount of water in the body is less then osmotic pressure of blood is reduced.
As a result of this osmoreceptors of hypothalamus are stimulated.
This activates pituitary gland and secretes anti-diuretic hormone (ADH) from posterior lobe.
Stimulation of ADH increases reabsorption of water and thus water level of the body increases.
Once the water level in the body is balanced, the effect of ADH is inhibited.
5 Discuss the role of kidney in maintenance of blood pressure. OR How kidney maintains BP?
• The juxtaglomerular cells in the kidney are responsible for this function.
When blood pressure decreases, it causes release of hormone renin by the kidneys.
Renin reacts with globulin in the blood and forms angiotensinogen which in turn forms angiotensin-I.
This angiotensin-I stimulates adrenal cortex to produce the aldosterone hormone which causes increased reabsorption of sodium.
This is followed by reabsorption of water and thus the blood volume increases and ultimately increases blood pressure.
Angiotensin-I is converted into angiotensin-II by the enzymes in the lungs.
Angiotensin-II is a powerful vasoconstrictor and thus increases blood pressure.
Thus, kidney helps to maintain blood pressure by these two ways.
6 Describe the structure of nephron with the help of diagram.
Explanation
The kidney is composed of about 1 million of functional units called nephrons.
The structure of nephron consists of two main parts.
Nephron (uriniferous tubule)
Glomerular capsule (Bowman’s capsule): It is a cup-shaped structure composed of a network of arterial
capillaries, called glomerulus. In glomerulus, blood is filtered under pressure of about 10 mm Hg.
Renal tubules: It is a long tube which extends from the neck of the nephron and consists of:
Proximal convoluted tubule (PCT)
Loop of Henle
Distal convoluted tubule (DCT)
Collecting tubule.
Function: Parts of renal tubules help in reabsorption and secretion of substances during formation of urine.
Renal artery and renal veins are supplying and collecting blood vessels throughout the renal tubules.
7 Explain the process of urine formation/mechanism/ stages of urine formation.
Formation of Urine Involves Three Main Stages
Ultrafiltration (Glomerular Filtration)
The filtration of blood under pressure is called ultrafiltration.
It occurs in glomerulus, hence named as glomerular filtration.
The blood containing waste material is carried into the glomerulus by afferent arterioles.
The walls of glomerular capsule act as a filter and blood is filtered under pressure of about 10 mm Hg.
About 125 ml of blood is filtered out per minute as a glomerular filtrate.
GFR: Glomerular filtration rate.
Definition: The volume of blood filtered through glomerulus in 1 hr is called glomerular filtration rate.
About 1 litre of blood is filtered in 1 hr. Thus, GFR is 10% (100 ml).
Selective Reabsorption (Active Reabsorption)
The process by which only useful substances are absorbed from the glomerular filtrate into the blood capillaries, is called selective reabsorption.
High threshold substances: The substances which are essential to the body and are selectively reabsorbed back into the blood circulation are called high threshold substances,
e.g. glucose, amino acids, vitamins, water.
Low threshold substances: The substances which are reabsorbed only up to a slight extent, are called low threshold substances, e.g. urea, uric acid.
Non-threshold substances/no threshold substances: The substances which are not reabsorbed at all from the glomerular filtrate are called non-threshold substances, e.g. creatinine, hippuric acid.
Active Secretion
Definition
“The process of transport of substances from blood into the filtrate again is called active secretion.”
The substances which are not filtered by glomerular capsule are carried in the capillaries of the efferent arteriole and they are cleared by active secretion into the urine.
In this way, process of urine formation completes.
8
What are the abnormal constituents of urine? Give their significance. OR Name the pathological conditions they signify.
The following are the abnormal constituents of urine.
Abnormal constituents
Significance/pathological conditions
1.
Proteins
Proteinuria
2.
Sugar
Glycosuria
3.
Ketone bodies
Ketonuria
4.
Bile pigments and salt
Jaundice
5.
Blood
Haematuria
6.
Pus
Pyuria
Proteins
The presence of proteins in the urine is called proteinuria. The presence of albumin and globulin in urine is called albuminuria and globulinuria.
The proteinuria results in the following pathological conditions:
Nephritis
Renal tuberculosis
Bacterial infections in kidney
Mercury poisoning.
Sugars
The presence of sugar in urine is called glycosuria. This is associated with the increased blood sugar levels exceeding the threshold level.
The glycosuria occurs in the following pathological conditions:
Diabetes mellitus
Renal glycosuria.
Ketone Bodies (Acetone Bodies)
When ketone bodies appear in the urine the condition is called ketonuria.
When ketone bodies appear in the blood the condition is called ketonemia.
Thus ketosis is a process in which ketonemia and ketonuria occur.
The acetone, acetoacetic acid and -hydroxy butyric acid are described as ketone bodies.
Ketonuria occurs in the following pathological conditions:
Carbohydrate starvation
Pregnancy
In anaesthesia.
Bile Pigments and Salts
When bile appears in the urine the condition is called jaundice. Sodium glycocholate and sodium taurocholate are bile salts while bilirubin and biliverdin are bile pigments.
In defective liver function bile appears in the urine and colour of urine becomes greenish yellow or greenish brown.
Bile pigments appear in all types of jaundice:
Haemolytic jaundice
Obstructive jaundice
Toxic jaundice.
Blood
When blood appears in urine the condition is called haematuria. In haemoglobinuria, the only haemoglobin pigment is found in urine.
Pathological conditions
Haematuria occurs due to kidney lesions.
Haemoglobinuria occurs in enteric fever, malaria, and haemolytic poisoning.
Snake venom causes haemolysis which results in presence of haemoglobin in urine.
Pus
The presence of pus in the urine is termed pyuria.
Pyuria is caused due to inflammation of the urinary bladder, urethra and pelvis of the kidney.
9 Give the characteristics and composition of normal urine.
Characteristics of urine
Composition of normal urine
Urine is amber in colour.
Specific gravity of urine is 1.020 to 1.030.
Urine is acidic in nature.
Healthy adult passes 1000 to 1500 ml of urine per day.
Water: 96%
Urea: 2%
Uric acid, chlorides, creatinine, phosphates, ammonia, sulphates, sodium, potassium, oxalates, glucose, oxalic acid.
Describe the disorders of urinary system/renal disorders/ pathophysiology of renal diseases.
(i) Anuria: It means absence of urine or complete suppression of urine.
Oliguria: It means reduced urinary output, i.e. about less than 400 ml of urine per day.
Polyuria: It means excessive secretion and discharge of urine by the kidneys.
Dysuria: It means pains and difficulties during micturition.
Nephritis: It means inflammation of kidney.
Kidney stone/urinary calculus/renal calculi: In this condition, there is a formation of stony material in the kidney or urinary tract.
The kidney stone is formed when the normal constituents of urine such as oxalates, phosphates, urates and uric acid are precipitated. This stone usually consists of more than one substances deposited in layers. Mostly the stone formation originates in the collecting tubule and then passes into the pelvis of kidney where they may increase in size. Those particles which are of large size may block a flow of urine in ureters. Those particles which are passed through ureters may obstruct the urethra.
Symptoms of Kidney Stone
Pains in the pelvic region.
Difficulty and pains during micturition.
Passage of pus and blood in the urine.
Evidence of renal failure.
Uneasiness.
Edema: An abnormal or excessive accumulation of tissue fluid in the intracellular spaces of the body is called edema. This increase in tissue fluid increases the volume of that part of the body. The skin appears puffy and when finger is pressed on it a dent is formed which remains for sometime and then reaches the normal level.
Edema is found in the skin below the eyes due to kidney and heart diseases.
Edema may be seen in subcutaneous tissues.
Causes of Edema
Blockage of venous drainage flow.
Deficiency of plasma proteins results in decrease in osmotic pressure of blood leading to edema.
Damage to capillary walls leaks the plasma proteins in the tissue spaces which leads to edema.
Blockage of lymphatic vessels may produce edema.
Types of Edema
Cardiac edema
Renal edema
Pulmonary edema
Cirrhotic edema
Nutritional edema.
Write a note on ‘micturition’.
Micturition
Discharge of urine from the urinary bladder is called micturition.
Micturition is an act of passing urine.
Micturition is also known as urination or voiding.
Micturition is an important function of urinary bladder.
Micturition occurs via a combination of involuntary and voluntary muscle contraction.
When the volume of urine in the bladder exceeds 200–400 ml, pressure within the urinary bladder increases considerably and there is a stimulus for contraction of the detrusor muscle and relaxation of the internal urethral sphincter muscle and thus urination takes place.
Write a note on ‘clearance test’/‘renal clearance test’/ tests for glomerular filtration.
Clearance Tests: Clearance tests are used to access the rate of glomerular filtration and renal blood flow.
The renal clearance of a substance is defined as the volume of plasma from which the substance is completely cleared by the kidneys per minute.
This depends on:
Plasma concentration of the substance and its excretion rate
GFR (normal—120 ml/min)
Renal plasma flow.
Clearance of the substance can be calculated by following equation:
C = U V,
P
where, C — clearance of the substances (ml/min)
U — concentration of the substances in urine (mg/L)
P — concentration of substance in plasma (mg/L)
V — volume of urine passed per min.
The substances which are used for clearance test include:
Endogenous – Creatinine, urea
Exogenous – Inulin
The Endocrine System
1 Define the terms—endocrine glands, exocrine glands and hormones.
Endocrine Glands
The ductless glands which secrete the hormones directly into the blood circulation are known as endocrine glands, e.g. pituitary gland, thyroid gland, adrenal gland, testes, ovaries.
Exocrine Glands
The glands having duct which secrete the enzymes/juices on the outer surface of the organs are called exocrine glands, e.g. salivary glands, lacrymal glands, gastric glands.
Hormones
Hormones are the chemical substances secreted by endocrine glands and are carried by bloodstream to another organ where these have an effect on the organ function, growth and nutrition,
e.g. growth hormone, oxytocin, insulin, glucagon.
2 Differentiate between endocrine glands and exocrine glands.
Endocrine glands
Exocrine glands
(i)
These glands do not possess duct and pour their secretions directly into the bloodstream.
These glands possess duct through which their secretions are poured on the outer surfaces of the organs of the body.
(ii)
The secretions of endocrine glands are hormones.
The secretions of exocrine glands are enzymes and juices.
Contd...
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Endocrine glands
Exocrine glands
(iii)
Functions of endocrine glands are metabolic, growth and balance of the body.
Functions of exocrine glands are related to digestion and absorption.
(iv)
Endocrine glands form a part of communication system with nervous system.
These do not form a part of communication system with nervous system.
(v)
Secretions of endocrine glands affect particular organs.
Exocrine glands show actions locally.
(vi)
Example: Pituitary gland, thyroid gland.
Example: Sweat glands, salivary glands.
3 Differentiate between hormones and enzymes.
Hormones
Enzymes
(i)
(ii)
(iii)
(iv)
(v)
Hormone is a chemical substance which is formed in one particular organ and is carried by bloodstream to another organ where it has an effect.
Hormones are the secretions of endocrine glands.
Hormones are secreted directly in the blood and pass to the target organs where it has its function.
Chemically, hormones are peptides, amines, steroids and derivatives of amino acids.
Example: ADH, GH, LH, ACTH, aldosterone, etc.
En zyme s are ch emi cal substances which convert complex food material into simpler form without itself being changed.
Enzymes are the secretions of exocrine gland.
Enzymes are secreted in the duct which opens near the organs where enzyme has its function.
Chemically, enzymes are proteins which catalyse a number of biochemical reactions.
Example: Ptyalin, pepsin, trypsin, etc.
4 Name endocrine glands of the body with their locations.
1. Pituitary gland: It is situated in the hypophyseal fossa of the sphenoid bone at the base of the brain.
Thyroid glands: It is situated in the neck in association with larynx and trachea at the level of Vth, VIth and VIIth cervical and 1st thoracic vertebrae.
Parathyroid glands: These are embedded in the posterior surface of each lobe of thyroid gland.
Adrenal glands: These are situated one on the upper pole of each kidney.
Islets of Langerhans cell: These are found in clusters, irregularly distributed throughout the substance of pancreas.
Pineal gland: It is a small body situated in the brain below the corpus callosum and posterior to 3rd ventricle of the brain.
Testes in male: They are suspended in the scrotum (skin) by spermatic cord.
Ovaries in female: These are situated one on each side of the uterus attached to the broad ligament and below the uterine tubes.
5 Name the hormones secreted by pituitary gland.
Pituitary gland
6 Write in brief about pituitary gland. Why is it called master gland?
Pituitary Gland
It is a small, reddish-greycoloured, pea-shaped gland situated near the hypothalamus of brain. Pituitary gland consists of two lobes:
Adenohypophysis (anterior lobe)
Neurohypophysis (posterior lobe).
The secretions of all other endocrine glands are mostly controlled by pituitary gland. Pituitary gland performs its function by ‘negative feedback mechanism’. Hence, called master gland of the body.
7 Give the functions of adenohypophysis/anterior pituitary lobe/gland (APG).
Functions of Adenohypophysis
Growth hormone: It controls growth and development of the body.
Thyrotropic hormones (TSH): It controls the growth and activity of thyroid gland.
Adrenocorticotropic hormone (ACTH): It stimulates adrenal cortex of the adrenal gland to produce the hormones ‘glucocorticoids’ and ‘mineralocorticoids’.
Lactogenic hormone (prolactin): In females, it stimulates the growth of breast and secretion of milk.
Gonadotropic hormones (sex hormones): With the help of FSH and luteinising hormones it controls secretion of sex hormones such as progesterone, oestrogen and testosterone.
8 Give the functions of neurohypophysis/posterior lobe of pituitary gland.
Functions of Posterior Lobe/Neurohypophysis
Oxytocin/Pitocin
It stimulates contraction of uterus during birth of a baby (parturition).
It secretes the milk after delivery.
It helps in the transport of sperms by contracting uterus.
Antidiuretic Hormone/ADH/Vasopressin
It contracts the arterial blood vessels and causes rise in blood pressure.
It reduces urine output, the effect is known as antidiuretic effect.
9 Explain the terms
(a) Dwarfism
It is a disorder caused by hypoactivity of pituitary gland, i.e. less secretion of anterior lobe of pituitary gland (mainly growth hormone).
Symptoms
Stunted growth of the body, i.e. adults are about 3 feet in height.
Bones and other organs do not grow enough.
Sex organs and secondary sex characteristics do not grow.
Metabolism is slightly disturbed.
(b) Gigantism
This disorder is caused by hyperactivity of pituitary gland,
i.e. excess secretion of growth hormone from anterior lobe of pituitary gland.
Symptoms
The height of individual is 7 to 8 feet.
Mental confusion may be observed.
Sweating is increased.
Metabolism shows hyperglycemia and glycosuria.
Muscles and viscera are proportionally large.
Organs concerned with metabolism such as heart, lungs, liver are enlarged.
Name the hormones of thyroid gland. Give the functions of thyroid hormones.
Hormones of Thyroid Gland
Thyroxine (T4)
Tri-iodothyronine (T3)
Thyrocalcitonin/calcitonin.
Functions of Thyroid Gland/Hormones
Thyroid hormones are essential for normal mental and physical development.
They are essential for maintenance of healthy skin and hairs.
They control utilization of oxygen in the body.
The hormone thyroxin stimulates the absorption of glucose in the body.
They increase fat content and milk secretion from mammary gland.
They increase heart rate and blood pressure.
Thyroxin controls the rate of cellular respiration and energy production in the mitochondria.
The hormone thyrocalcitonin reduces the blood level of calcium.
Explain the term goitre.
Goitre
It is caused by deficiency of iodine and production of less thyroid hormones from thyroid gland.
Symptoms
An abnormal enlargement of thyroid gland
Body weight increases
Swelling of the neck
Restlessness
Nervousness
Mental excitement
Disturbed sleep pattern.
Write a note on diabetes mellitus.
The hyposecretion of insulin from the -cells of islets of Langerhans cells leads to increased blood sugar level. The sugar passes through urine, the condition is called diabetes mellitus.
The ‘diabetes’ means large volume of urine is passed. The term ‘mellitus’ means sweet.
In diabetes mellitus, the blood glucose level exceeds normal renal threshold level (180/100 ml) and hence glucose is found in urine.
Types of Diabetes Mellitus
Maturity onset type: It occurs after the age of 40 years. In this case, there is some defect in the release of insulin from -cells.
Juvenile onset type: It occurs before the age of 20 years. In this case, -cells are not functional.
Effects or Symptoms/Characteristics of Diabetes Mellitus
Raised blood glucose level (hyperglycemia)
Glycosuria
Polyuria
Polydypsia (excess thirst)
Weight loss
Dehydration
Weakness
Restlessness
Hyperventilation
Acidosis
Skin, mouth, tongue becomes dry
Increased rate of breathing.
Treatments
Insulin injection
Low intake of sugar
Exercise.
Differentiate between ‘diabetes mellitus’ and ‘diabetes insipidus’.
Diabetes mellitus
Diabetes insipidus
(i)
It is caused due to hyposecretion of insulin.
It is caused due to hyposecretion of ADH.
(ii)
It is a disorder of pancreas
It is a disorder of posterior pituitary gland.
(iii)
There is increase in blood sugar level.
No increase in blood sugar level.
(iv)
Glucose is excreted in urine (glucosuria).
No glucosuria.
(v)
Ketone bodies occur in blood and urine.
Ketone bodies do not occur in blood and urine.
(vi)
There is excess of hunger (polyphagia).
No polyphagia.
The Reproductive System
1 Define the terms.
1. Reproduction: It is the process by which genetic material is passed from one generation to another generation and thus maintains continuation of species,
i.e. the mechanism by which thread of life is sustained.
Puberty: Puberty is the age at which all internal reproductive organs reach the maturity.
Menopause: It is the period which occurs between the age of 45 to 55 years and marking the end of childbearing period. Or it means permanent cessation of menses.
Ovulation: The process of maturation of graafian follicle and liberation of ovum is termed as ovulation.
Fertilization: Fertilization is the process of fusion of spermatozoa with the ovum which normally takes place in ampulla part of the fallopian tube.
Menstruation/menstrual cycle: The periodic discharge of blood, ovum, mucus and cellular debris from uterus to vagina at about 28 days interval is called menstruation.
2 Name the organs/parts of the male reproductive system.
Parts of Male Reproductive System
Testes (2)
Epididymis (2)
Vas deferens/deferent ducts (2)
Ejaculatory ducts (2)
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Penis (1)
Urethra (1)
Accessory sex glands
Seminal vesicles (2)
Prostate gland (1)
Cowper’s glands (bulbourethral glands) (2).
3 Draw and label a diagram of male reproductive system.
The male reproductive system
4 Write a note on testis.
Testes
These are two oval-shaped bodies one on each side in the scrotum.
The scrotum helps in regulation of body temperature for testis. The muscles of scrotum either contract or relax in response to cold and warmth to in order to maintain optimum temperature for formation of spermatozoa. The process of spermatogenesis is better when the temperature of testes is less than 3ºC than normal body temperature.
Each testis is covered by 3 layers:
Tunica vaginalis (outer)
Tunica albuginea (middle)
Tunica vasculosa (inner)
Internally, each testis consists of about 5000 convoluted tubules called seminiferous tubules.
Spermatozoa are formed in the walls of these seminiferous tubules. The seminiferous tubules unite at upper end of testis and form a network-like structure called epididymis.
Functions of Testes
Testes produce spermatozoa by the process of spermatogenesis.
Testes secrete the hormone testosterone.
5 Describe various accessory sex glands in male.
Accessory Sex Glands in Male
Seminal vesicle: These are two sac-like glands present at the base of urinary bladder. These ducts join with vas deferens and form ejaculatory duct.
Functions
It provides nourishment to the sperms.
It increases mobility of sperms.
Prostate glands: It is the largest accessory gland which surrounds the anterior part of urethra.
Functions
Its secretions activate the sperms and provide nourishment to the sperms.
Its secretions neutralise the acidity of urine.
It secretes a fluid containing proteolytic enzymes which helps in liquification of seminal fluid.
Cowper’s glands: These are two pea-shaped glands situated at the base of the penis. There ducts open into the bulb of urethra.
Functions
These glands secrete an alkaline substance that protects the sperms by neutralising acid environment of urethra.
The mucus secreted by these glands lubricates passage of urethra.
During sexual excitement the Cowper’s gland secretes a clear viscous fluid which further lubricates urethra.
6 Explain the structure of sperm/spermatozoon with the help of a diagram.
Spermatozoon/Sperm
Spermatozoon is a motile living male gamate produced by seminiferous tubule of the testes by the process of spermatogenesis.
Structure
The sperm
The total length of spermatozoon is 55 to 65 . The spermatozoa has four main parts.
Head: Head of the sperm is flat and consists of nucleus. The nucleus is covered at anterior end by acrosomal cap. ‘Acrosomal cap’ produces an enzyme ‘hyaluronidase’ which dissolves the egg membrane so that penetration of sperm into ovum takes place.
Neck: It connects the head to the middle piece, i.e. to the body. It is short and weak. It contains centriole.
Body: The body has rings of fibrils with sheath and represents mitochondria.
Tail: Tail of sperm has two parts:
Principle piece: It is the longest portion of the tail having length of 42 to 50 . It is without mitochondrial sheath.
Tail piece: It is a short, slender and about 5 to 10 in length. It has typical appearance of flagellum and consists of microtubules surrounded by plasmalemma that covers the entire sperm.
7 Write a note on seminal fluid or semen.
Semen
Semen is a fluid ejaculated from urethra of male during coitus,
i.e. sexual stimulation. Semen is a thick whitish fluid which is very viscous in nature. It is slightly alkaline and has pH of about 7.4.
Composition of Semen
Semen is composed of:
Spermatozoa in testes
A viscous fluid from seminal vesicles
Secretion of prostate gland
Secretion of Cowper’s gland
Mucus secreted by glands.
Functions of Semen
Semen contains spermatozoa which are to be introduced into female vagina during coitus.
After ejaculation of semen, the individual satisfies full sexual pleasure.
8 Define puberty. What are the changes involved in male during puberty?
Puberty
Puberty is the age of maturity at which all the reproductive organs reach to the maturity.
In case of male, puberty occurs between the ages of 10 to 14 years.
The hormone testosterone secreted in this stage influences the development of body to sexual maturity.
The Changes which Occur at Puberty in Males
Growth of muscles and marked increase in height and body weight.
Enlargement of larynx and deeping of voice breaks.
Growth of hairs on face, chest, abdomen and pubis.
Enlargement of penis, scrotum and prostate gland.
Maturation of seminiferous tubules and production of spermatozoa.
Ejaculation of seminal fluid.
9 Name the parts/organs of female reproductive system.
Write in short about uterus.
Uterus
Uterus is a thick muscular pear-shaped bag situated between urinary bladder and rectum. It measures about 8 cm in length, 5 cm in breadth and 2 cm in thickness. It consists of three parts:
Fundus: It is an upper dome-shaped part of uterus.
Body: It is middle part of uterus.
Cervix: It is lower part of uterus which opens into vagina by external os.
The walls of uterus consist of three layers:
Perimetrium
Myometrium
Endometrium.
Functions
It provides space for growth and development of embryo.
It plays an active role in menstruation.
It receives fertilized ovum and allows for implantation.
It expels the foetus by contraction.
It receives the sperms during coitus.
Draw and label a diagram of female external reproductive system.
Draw and label a diagram of female internal reproductive system.
Write a note on ovaries.
Ovaries
Ovaries are two female sex organs situated near the kidney on either side of uterus. Each ovary is attached to the uterus by an ovarian ligament.
Functions of Ovaries
Ovaries help in formation, development and liberation of ovum.
It helps in production of oestrogen by graafian follicles.
It helps in production of progesterone by corpus callosum.
Define puberty. Explain physiological changes occurring in female during puberty.
Puberty
It is the age at which all internal reproductive organs reach to the maturity.
Puberty usually occurs at the age of 10 to 14 years in girls.
It is marked by ‘onset of menstruation’.
Physiological Changes Observed in Female during Puberty
Onset of menstruation and ovulation.
Enlargement of vagina and breast.
Growth of axillary and pubic hairs.
Maturation of ovaries, uterus and uterine tubes.
Increase in rate of growth in height and widening of the pelvis.
Increased deposition of fat in subcutaneous tissue.
Mental and emotional maturity.
Write in brief about ‘menopause’.
Menopause
It is a period which occurs between the age of 45 to 55 years and marking the end of child-bearing period.
Menopause means permanent cessation of menses.
Menopause is caused by changes in concentration of sex hormones.
Ovaries become less responsive to FSH and LH stimulation. Hence, ovulation and menstrual cycle becomes irregular and stops immediately.
Changes involved in Female during Menopause
Breast shrinks.
Axillary and pubic hairs become sparse.
Atropy of sex hormones.
Episodes of uncharacteristic behaviour.
Sweating.
Palpitation (rapid forceful heartbeat).
Discomfort and disturbances of normal sleep pattern.
Explain the terms.
1. Amenorrhoea: It means an absence of menses, i.e. menstrual fluid.
Dysmenorrhoea: It means painful menstruation in women comes during first day of the menstruation period often within an hour the start of bleeding.
Leucorrhoea: Excessive discharge of fluid from the cervix of the uterus, vagina and associated glands with appearance of discharge of WBCs.
Galactorrhoea: It means excessive flow of milk from the breast, i.e. mammary glands.
Migraine: It means recurring paroxysmal headache mostly occurs unilateral, associated with nausea, vomiting and visual disturbances in female during menstrual cycle.
Describe microscopic structure of ovary with the help of diagram.
Explanation
Microscopic structure of ovary
The germinal epithelium: It is the outer layer of simple epithelium that covers the surface of ovary and is continuous with mesothelium that covers mesovarium.
The tunical albugenia: It is a capsule below germinal epithelium.
The cortex: It surrounds the medulla. It contains ovarian follicle in various stages of maturity, each contains an ovum. Before puberty it contains immature follicles (primordial follicles), which the female has from birth. During the childbearing years (after puberty), one ovarian follicle matures (graafian follicle) and ruptures and releases ovum into the peritonial cavity and occurs during each menstrual cycle. The ruptured follicle developes into the corpus luteum which in turn becomes corpus albicans.
Medulla: It lies in the centre and consists of fibrous tissue, blood vessels and nerves.
Define menstrual cycle. Describe the phases of “menstrual cycle”/menstruation.
Menstrual cycle: It is a series of changes in endometrium of a female, every 26 to 30 days throughout the childbearing period.
The phases of menstrual cycle are devided into:
Menstrual phase (04 days):
It is characterized by periodic discharge of 25–65 ml of blood, tissue fluid, mucus and epithelial cells.
It is caused by sudden reduction in oestrogen and
progesterone and lasts for approximate 4–5 days.
During menstrual phase, ovarian cycle is also in operation and primary follicle begins its development.
At birth, each ovary contains 200,000 follicles each consisting of primary ovum surrounded by single epithelium.
Towards the end of menstrual phase, many primary follicles developed into secondary follicle which consist of secondary ova.
Proliferative phase (10 days):
It is characterized by release of oestrogen.
During this, endometrium gets proliferated and it gets renewed in this period.
Also, graafian follicle is maturing and this phase is terminated when ovulation occurs and oestrogen production is inhibited.
Secretory phase (14 days):
Immediately after ovulation, the cells lining of ovarian follicle are stimulated by LH to develop corpus luteum which further produces progesterone.
Under the influence of progesterone, the endometrium becomes oedematous and secretory glands produce an increased amount of watery mucus which is also called luteal phase.
If the implantation of fertilized ovum occurs, then endometrium grows further.
Then the menstrual cycle is interrupted during the period of lactation. If ovum is not fertilized, the cycle enters in the next phase.
19
Differentiate between spermatogenesis and oogenesis.
Spermatogenesis
Oogenesis
1.
It occurs inside the testis.
It occurs inside the ovary.
2.
All stages are completed
Major part of oogenesis occurs
inside the testis.
inside ovary but last stage occurs
inside oviduct.
3.
Spermatogenia develop
Oogonia develop from germinal
from germinal epithelium
epithelium overlying the ovary.
lining of the seminiferus
tubules.
4.
All spermatogonia divides
Only some oogonia give rise to
to form spermatozoa.
oocytes.
5.
Growth phase is short.
Growth phase is prolonged.
6.
A spermatocyte forms four
A oocyte forms only one egg or
spermatozoa.
ovum.
7.
Reserve food is little in the
Ovum collects a lot of reserve food
sperms.
and other biochemicals.
8.
It produce motile male
It forms non-motile female
gametes.
gametes.
20
What is pregnancy? Explain various stages of pregnancy.
Pregnancy: Pregnancy is the time during which one or more offspring develops inside a woman.
Common symptoms and discomforts of pregnancy:
Tiredness
Constipation
Pelvic girdle pain
Back pain
Increased urinary frequency
Haemorrhoids (piles)
Heart burn, nausea
Breast tenderness
Pregnancy-related stretch marks
Stages of pregnancy (physiology of pregnancy): Fertilization is the event where the egg cell fuses with male gamete, spermatozoon to produce zygote, which is then implanted into the uterus.
Fertilization (conception) is sometimes used as the initiation of pregnancy.
First trimester (week 1 to week 12)
Second trimester (week 3 to week 28)
Third trimester (week 29 to week 40)
First trimester: In this stage, woman undergoes many changes. Hormonal changes affect almost every organ system in female body. Menstruation period stopping is a clear sign of pregnancy of woman.
Other signs include—extreme tiredness, swollen breasts, nipples might also stickout, morning sickness, distaste of certain foods, mood swings, constipation, need to pass urine more often, headache, heartburn, weight gain or loss.
Second trimester: In this stage woman’s abdomen is expanding as the baby continues to grow.
Other changes during this stage—body aches stretch marks on abdomen, breast, thighs or buttocks, darkening of skin around nipples, patches of darker skin usually over the cheeks, forehead, nose or upper lip, numb or tingling hands, itching on the abdomen, palms and sole of feet, swelling of ankles, fingers and face.
Third trimester: In this stage some new body changes noticed, i.e. shortness of breath, heartburn, hemorrhoids, tender breast which may leak a watery pre-milk called colostrum. The baby dropping or moving lower in the abdomen, which can be the sign of real or false labour.
21 What is parturition? Give the mechanism and control of parturition.
Parturition
Parturition is the process of expelling of the fully formed baby from the mother’s uterus after pregnancy period. Parturition is the process of giving birth.
Mechanism and control of parturition: Parturition is induced by a complex neuroendocrine mechanism which is triggered by fully formed foetus and the placenta called as foetal ejection complex.
Parturition is controlled by two hormones.
Oxytocin: It causes powerful contractions of myometrium during parturition and pushes the young baby gradually outside.
Relaxin: It causes widening of pelvis by relaxing the pubic symphysis of the pelvic girdle.
Parturition is also called childbirth or process of bringing out a child from the uterus or womb.
Objective Questions with Answers
Fill in the Blanks
Mitochondria are called storehouse of energy.
The process of swallowing is called deglutition.
Cerebellum is concerned with maintenance of posture and balance of the body.
Larynx is called voice box.
Phagocytosis is a function of WBCs.
Inflammation of joint is known as arthritis.
The hormone concerned with regulation of basic metabolic rate is thyroxine.
The decrease in number of RBCs in the blood is called
anaemia.
Absence of dilute HCl in the gastric juice in the stomach is called achlorhydria.
Menopause occurs in female between the age of
45–55 years.
Astigmatism is corrected by wearing cylindrical lens.
Viscosity of blood is 4.5 to 5.5.
Melatonin is secreted by pineal gland.
Formation of clot inside the blood vessel is called
thrombosis.
The normal value of blood pressure is 120/80 mm of Hg.
Total length of small intestine is about 5 meters.
55
1
Which part of ear resembles snail shell? — Cochlea
Tongue is attached to the bone, called hyoid bone.
The gap between two neurons is called synapse.
Absence of urine means anuria.
Deposition of fat inside the walls of artery—this condition is called arteriosclerosis.
Total number of vertebrae in the human body are 33.
Deficiency of iodine causes goitre.
The enzymes trypsin and chymotrypsin are present in
pancreatic juice.
Which part of the eye is known as ‘window of eye’? —
Cornea
Which blood group is called universal donor? — Blood group ‘O’
Micturition is a function of urinary bladder.
The normal values of RBCs are 5 million per cubic mm of blood.
The cardiac cycle time is 0.8 sec.
Saliva secretion is present in oral/mouth cavity.
Patella is a sessamoid bone.
SA node is called pace maker.
Normal value of WBCs is 6000–10000 per cubic mm of blood.
Sternum is bone of thoracic cavity.
Vasopressin (ADH) is a hormone secreted by pituitary gland.
The end of child bearing period is called menopause.
Puberty is an age of maturity.
Nephrons are the structural and functional units of the
kidney.
Increase in number of RBCs means polycythemia.
Coverings of the brain and spinal cord are called
meninges.
Normal value of vital capacity is 5 litres.
Appendix is an organ of digestive system.
Sacrum consists of 5 fused vertebrae.
Sebaceous glands are present in the skin.
Which one is a common part of both respiratory and digestive system? — Pharynx
Lysosomes are called suicidal packet of the cell.
Viscosity of blood is 4.5 to 5.5.
Blood group ‘AB’ is known as universal blood recipient.
Meatus is a tube-shaped cavity within a bone.
Facet is a small, flat articulating surface.
Sutures are the fixed joints between the bones of skull and cranium.
Articulation is the joint between two or more bones.
Nucleus is largest organelles of the cell.
Cartilage is a flexible connective tissue.
Neurone is basic structural and functional unit of nervous system.
Study of cell is known as cytology.
pH of blood is 7.45 to 7.55.
The normal values of platlets are 3 to 4 lacs/mm3 of blood.
The fluid remaining after formation of clot is known as
blood serum.
Prothrombin and fibrinogen are plasma proteins essential for blood clotting.
Haemolysis means breakdown of RBCs.
Normal pulse rate of healthy human is 72–75.
Stroke volume ejects 70 ml of blood.
Mitral valve consists of two cusps.
Normal capacity of urinary bladder to store urine is
400–600 ml.
The net filtration pressure of kidney is 10 mmHg.
Each kidney consists of 1 millions of nephrones.
Right lung is thicker and broader than left lung.
Larynx consists of 9 cartilages.
Normal value of tidal volume is 500 ml.
Chief cells of stomach secretes enzyme pepsin.
The life span of RBCs is 120 days.
Normal value of bleeding time of blood is 1–3 minutes.
Normal value of clotting time of blood is 4–10 minutes.
In the middle ear, Hammer-shaped bone is known as
malleus.
In the middle ear, anvil-shaped bone is known as incus.
Human body consists of total 206 bones.
Stapes is the smallest of the body.
Femur is the longest and strongest bone of the body.
Cerebrum is the largest part of the brain.
Angiology is the study of blood circulation.
Plasma membrane is composed of protein and lipid.
Study of microscopic structure of tissues is called
histology.
Back side of the body is called dorsal side.
Ribosomes are the sites of protein synthesis (protein factories)
Which type of cartilage is present at the ends of the bones? — Hyaline cartilage
The smallest organelle of the cell is ribosomes.
Mandible is only the movable bone of the skull.
Tonsils are located in the pharynx.
Shoulder joint is an example of ball and socket joint.
Which bone is called collar bone? — Clavicle
Patella is a bone of lower limb.
The last two pairs of ribs are called floating ribs.
Which organ is known as ‘graveyard’ of the RBCs?
Spleen
The ABO system of blood group is discovered by Karl Landsteiner.
Which hormone stimulates RBC production? — Erythro-poietin
Life span of platelet is 7 to 10 days.
The average volume of blood presents in the human body is 5.5 litres.
All arteries carry oxygenated blood except — pulmonary artery.
Mitral valve is also known as bicuspid valve.
Vocal cord is located in the larynx.
DNA is mainly present in the nucleus.
The interval between cell division is called interphase.
Tissue responsible for elasticity and tensile strength is
areolar tissue.
Rhythmicity is a property of cardiac muscles.
Megaloblastic anaemia (macrocytic anaemia) occurs due to deficiency of vitamin B12 and folic acid.
Thrombocytopenia occurs due to decrease in platelet count.
The leucocytes are produced in lymph glands.
The clotting of blood is due to blood platelets.
Purkinje fibres are present in the heart.
The only artery which contains deoxygenated blood is
pulmonary artery.
Electrocardiogram gives information about state of myocardium.
The amount of blood expelled during each contraction of the ventricles is called stroke volume.
Baroreceptor is concerned with control of blood pressure.
Blood is supplied to the heart muscles through coronary artery.
The right side of the heart contains impure blood.
The number of temporary teeth in human beings are 20.
Parotid glands are present in mouth cavity.
Sodium taurocholate and sodium glycocholate are bile salts help in the digestion of fats.
Which gland has both endocrine and exocrine functions?
Pancreas
Liver is a storage site for glycogen.
The proteolytic enzyme of pancreatic juice is trypsin.
Pharyngeal tonsils produce antibodies.
‘C’ shaped cartilages are present in the trachea.
The number of respiratory cycles per minute in normal quite breathing are 15.
The normal value of expiratory reserve volume is
1400 ml.
Water is reabsorbed in tubules due to the effect of
aldosterone.
Glucose reabsorption takes place mainly in the proximal convoluted tubule (PCT).
Polyuria is a condition characterized by increased urine formation.
T3 and T4 hormones are secreted by thyroid gland.
Parathormone regulates the blood concentration of
calcium.
Myocardium is the middle layer of heart which consists of cardiac muscles.
The largest cranial nerve is trigeminal nerve.
The adrenal gland is situated on upper pole of each kidney.
The enzyme renin is secreted by kidney.
Beta cells of islets of Langerhans in pancreas secrete the hormone insulin.
Graves’ disease is related to hyperthyroidism.
Diabetes insipidus occurs due to deficiency of antidiuretic hormone.
Tetany is related to disorder of adrenal cortex.
Addison’s disaease is related to adrenal gland.
Oxytocin is secreted by posterier lobe of pituitary gland.
The first vertebra of the vertebral column is atlas.
The total number of Pairs of ribs of thoracic cage are
Knee joint is a type of hinge joint.
The terminal portion of the vertebral column is called
coccyx.
The ear is supplied with 8th cranial nerve.
The tympanic membrane is also known as eardrum.
Night blindness is caused due to deficiency of vitamin A.
Ovary releases egg once in a month.
Rods and cones are present in the retina.
In female ovulation takes place in a regular menstrual cycle on 14th day.
A person who cannot see object at a far distance is having
myopia.
Hypoglossal cranial nerve is related to movement of tongue.
Bile is produced by liver.
Cowper’s gland is a part of male reproductive system.
Schwann cells are present in axon.
Spermatozoa are formed in the seminiferous tubules of the testes.
Haversian system is characteristic feature in the histology of bone.
Accumulation of uric acid crystals in the synovial joints causes a disease called gout.
The blood contains 90% of water.
Hemoglobin is a protein.
Haemopoiesis is a process of the production of erythrocytes.
Blood is a fluid connective tissue.
The lymphatic fluid is colourless and alkaline.
Cardiac output is about 5 litres of blood.
Pleurae are the membranes around the lungs.
Nephrons are also known as uriniferous tubules.
‘U’shaped part of the renal tubule of a nephron is called
loop of Henle.
Ducts of Bellini are formed by collecting ducts.
Micturition is the term applied to the movement of urine out of urinary bladder.
A tendon joins a muscle with bone.
A ligament joins bone with bone.
The colour of the eye depends upon the colour of the
iris.
Ciliary body in the eyeball is an extension of choroid.
“Organ of Corti” is a part of internal ear.
Relaxin is a hormone secreted by the ovary.
Fertilization takes place in female in oviduct (fallopian tubes).
Corpus luteum is formed of dead graafian follicles.
Umbellical cord joins foetus to placenta.
Abnormal narrowing of blood vessel is known as
stenosis.
Deglutition is a function of oesophagus.
Ptyalin is an enzyme found in saliva.
Bile is stored and concentrated in the gall bladder.
BMR means basal metabolic rate.
When bile appears in the urine, the condition is called
jaundice.
In an adult each kidney weighs about 140 g.
Hypermetropia means long sightedness.
The juxtaglomerular cells in the kidney are responsible for maintenance of blood pressure.
Nephritis means inflammation of kidney.
Dysuria means pains and difficulties during micturition.
An abnormal excessive accumulation of tissue fluid in the intracellular spaces of the body is called edema/oedema.
Radioulnar joint is an example of pivot joint.
There are 11 pairs of intercostal muscles in the thoracic cavity.
Coronal suture is present between the frontal and parietal bones.
The fluid present in the anterior chamber of the eye is called aqueous humour.
Pituitary gland is situated in the hypophyseal fossa of the sphenoid bone at the base of the brain.
Dwarfism is a disorder caused by hypoactivity of pituitary gland.
Cerebrospinal fluid (CSF) presents in the brain acts as a cushion and shock absorber.
Olfactory nerve is related with the sensation of smell.
The saggital suture is present between two parietal bones.