Assignment Code: MFN-001/AST-1/TMA/-1/23-24

Course Code: MFN-001

Assignment Name: Applied Physiology

Year: 2023-2024

Verification Status: Verified by Professor

Q1a) List the major categories of cells on the basis of the level of differentiation.

Ans) Major Categories of Cells Based on Differentiation: Cells can be categorized based on the level of differentiation, which refers to how specialized or mature a cell is in performing its functions.

The major categories include:

a) Totipotent Cells: These cells have the potential to differentiate into any cell type in the body and can give rise to both the embryo and extraembryonic tissues.

b) Pluripotent Cells: Pluripotent cells have the ability to differentiate into a wide range of cell types but not extraembryonic tissues. They are found in the inner cell mass of the blastocyst.

c) Multipotent Cells: Multipotent cells are more specialized than pluripotent cells and can differentiate into a limited range of cell types within a particular tissue or organ.

d) Unipotent Cells: Unipotent cells can only differentiate into one specific cell type. They are often found in regenerative processes within specific tissues.

Q1b) Draw and label the structure of Eukaryotic cell.

Ans) A eukaryotic cell is characterized by the presence of a true nucleus enclosed by a nuclear membrane. Here's a simplified diagram and labelling of a eukaryotic cell:

Eukaryotic Cell Structure

a) Cell Membrane: The outer boundary that separates the cell's interior from its external environment.

b) Nucleus: Contains genetic material (DNA) and controls cell activities.

c) Cytoplasm: The gel-like substance that surrounds organelles and holds them in place.

d) Endoplasmic Reticulum (ER): Involved in protein and lipid synthesis.

e) Ribosomes: Sites of protein synthesis.

f) Golgi Apparatus: Modifies, sorts, and packages proteins for transport.

g) Mitochondria: Generates ATP through cellular respiration.

h) Lysosomes: Contain enzymes for cellular digestion.

i) Peroxisomes: Involved in lipid metabolism and detoxification.

j) Cytoskeleton: Provides structural support and facilitates cell movement.

k) Vacuole (Plant Cells): Stores water and various substances.

l) Chloroplasts (Plant Cells): Site of photosynthesis, producing sugars.

m) Cell Wall (Plant Cells): Provides structural support and protection.

Q1c)What is the composition of blood?

Ans) Blood is composed of several components, including:

a) Red Blood Cells (Erythrocytes): They transport oxygen from the lungs to body tissues and carry carbon dioxide away from tissues to the lungs for exhalation.

b) White Blood Cells (Leukocytes): These are involved in the immune response, defending the body against infections and foreign invaders.

c) Platelets (Thrombocytes): Small cell fragments that play a crucial role in blood clotting and wound healing.

d) Plasma: The liquid component of blood, making up about 55% of blood volume. Plasma contains water, electrolytes, proteins, hormones, waste products, and nutrients.

e) Plasma Proteins: These include albumin (maintains osmotic pressure), globulins (transport proteins and antibodies), and fibrinogen (essential for blood clotting).

f) Other Solutes: Blood also contains dissolved gases (oxygen and carbon dioxide), waste products (urea, creatinine), nutrients (glucose, lipids), and electrolytes (sodium, potassium, calcium, etc.).

Q2a) What do you understand by “MHC”. What are its types?

Ans) The major histocompatibility complex (MHC) is a set of genes that encode cell surface proteins essential for the immune system. MHC molecules are found in nearly all vertebrates, including humans. They play a crucial role in presenting antigens to immune cells, allowing the immune system to distinguish between self and non-self-cells.

There are two main classes of MHC molecules:

a) Class I MHC (MHC-I): These molecules are found on the surface of most nucleated cells in the body. They present antigens derived from within the cell to cytotoxic T cells. MHC-I helps the immune system detect and eliminate infected or abnormal cells.

b) Class II MHC (MHC-II): These molecules are primarily found on antigen-presenting cells (e.g., dendritic cells, macrophages, B cells). MHC-II presents antigens derived from external sources, such as pathogens, to helper T cells. This interaction triggers an immune response.

Q2b) What is Antibody Mediated Immune System? Explain briefly its mode of action.

Ans) Antibody-mediated immune response, also known as humoral immunity, involves the action of antibodies (immunoglobulins) produced by B cells. Here's a simplified overview of its mode of action:

a) Antigen Recognition: B cells are activated when they encounter an antigen, which is a foreign substance or pathogen. The B cell receptor (BCR) on the B cell's surface binds to the antigen.

b) B Cell Activation: Upon antigen binding, B cells are activated and differentiate into plasma cells. Plasma cells are responsible for antibody production.

c) Antibody Production: Plasma cells secrete antibodies specific to the antigen. These antibodies circulate in the blood and other bodily fluids.

d) Antibody-Antigen Binding: Antibodies bind to the antigen, forming antigen-antibody complexes. This binding can neutralize pathogens, mark them for destruction, or facilitate other immune responses.

e) Effector Functions: Antibodies have various effector functions, such as neutralization (preventing pathogens from infecting cells), opsonization (marking pathogens for phagocytosis), activation of the complement system (a group of proteins that enhances immune responses), and more.

f) Memory B Cells: Some B cells become memory B cells, providing immunological memory. If the same antigen is encountered in the future, memory B cells can mount a faster and more effective response.

Q2c) Enlist four laboratory tests that can detect antigen-antibody interaction.

Ans) Various laboratory tests are available to detect antigen-antibody interactions, including:

a) Enzyme-Linked Immunosorbent Assay (ELISA): Used to detect the presence of specific antigens or antibodies in a sample, such as in the diagnosis of infectious diseases.

b) Western Blot: A technique for detecting specific proteins by using antibodies to identify target antigens, commonly used in molecular biology and diagnostics.

c) Immunofluorescence Assay (IFA): Utilizes fluorescently labelled antibodies to visualize the presence and location of specific antigens in cells and tissues.

d) Hemagglutination Assay: Involves the clumping (agglutination) of red blood cells due to antigen-antibody reactions, used in blood typing and diagnostics.

Q3a) Explain one cardiac cycle and factors affecting cardiac output

Ans) Cardiac Cycle: The cardiac cycle is the sequence of events that occurs during one heartbeat, involving the contraction and relaxation of the heart's chambers. A typical cardiac cycle includes the following phases:

a) Atrial Contraction (Atrial Systole): The cycle begins as the atria contract, forcing blood into the ventricles. The atrioventricular (AV) valves are open, and the semilunar valves are closed.

b) Ventricular Contraction (Ventricular Systole): Both ventricles contract, generating pressure that closes the AV valves to prevent backflow into the atria. The semilunar valves open, allowing blood to be pumped into the pulmonary artery and aorta.

c) Isovolumetric Relaxation: After ventricular systole, all heart valves are briefly closed, and the ventricles start to relax. This phase allows the ventricles to fill with blood as pressure drops.

d) Ventricular Filling: As the ventricular pressure falls below atrial pressure, the AV valves open, allowing blood to flow from the atria into the ventricles. This phase marks the end of diastole.

Factors Affecting Cardiac Output

Cardiac output (CO) is the volume of blood pumped by the heart per minute and is influenced by two main factors:

a) Heart Rate (HR): This is the number of heart beats per minute. An increase in heart rate leads to an increase in cardiac output. Factors affecting heart rate include the autonomic nervous system, hormones, and physiological demands (e.g., exercise).

b) Stroke Volume (SV): Stroke volume is the volume of blood ejected by the ventricle with each heartbeat. It is influenced by factors like preload (the amount of blood returning to the heart), afterload (the resistance the heart must overcome to pump blood), and contractility (the strength of the heart's contractions).

1) Preload: Increased preload usually leads to an increased stroke volume and, consequently, increased cardiac output.

2) Afterload: Increased afterload can reduce stroke volume, decreasing cardiac output.

3) Contractility: Enhanced contractility can lead to increased stroke volume and, subsequently, increased cardiac output.

Q3b) What is blood pressure? Enumerate the mechanisms that regulate blood pressure.

Ans) Blood Pressure: Blood pressure is the force exerted by the circulating blood against the walls of the blood vessels. It is typically measured in millimetres of mercury (mmHg) and expressed as systolic pressure over diastolic pressure (e.g., 120/80 mmHg).

Mechanisms that Regulate Blood Pressure

Several physiological mechanisms help regulate blood pressure:

a) Baroreceptor Reflex: Baroreceptors are pressure-sensitive receptors located in the walls of blood vessels and the aorta. They sense changes in blood pressure and send signals to the brain, which adjusts heart rate and vascular tone to maintain blood pressure within a normal range.

b) Renin-Angiotensin-Aldosterone System (RAAS): When blood pressure drops, the kidneys release the enzyme renin, which leads to the production of angiotensin II. Angiotensin II constricts blood vessels, raises blood pressure, and stimulates aldosterone release to retain sodium and water.

c) Vasomotor Center: This area in the brainstem regulates blood vessel constriction and dilation, controlling vascular resistance and, thus, blood pressure.

d) Hormonal Regulation: Hormones such as epinephrine and norepinephrine released by the adrenal glands can increase heart rate and blood vessel constriction, temporarily raising blood pressure.

e) Fluid Volume Regulation: Blood pressure can be influenced by changes in blood volume, which is regulated by the balance of water and electrolytes, as well as the action of the kidneys.

f) Local Factors: Autoregulation at the tissue level can affect blood flow and pressure by adjusting vessel diameter in response to tissue oxygen demand.

Q3c) What is EEG? How is it useful?

Ans) EEG is a non-invasive neurophysiological test that records the electrical activity of the brain. It involves placing electrodes on the scalp to detect and record the brain's electrical signals.

EEG is useful for various purposes, including

a) Diagnosing Epilepsy: EEG is commonly used to diagnose epilepsy and monitor seizure activity. Specific patterns seen in EEG recordings can help confirm epilepsy and guide treatment.

b) Studying Sleep Disorders: EEG is employed in sleep studies (polysomnography) to monitor brain activity during sleep. It aids in diagnosing conditions like sleep apnea and narcolepsy.

c) Assessing Brain Function: EEG can assess brain function and detect abnormalities in cases of head injuries, tumours, and neurological disorders.

d) Research and Neurofeedback: EEG is used in neuroscientific research to study brain function, cognitive processes, and neural correlates of various conditions. It's also utilized in neurofeedback, a technique to help individuals control brain activity for therapeutic purposes.

e) Monitoring Anaesthesia: EEG can be used during surgery to monitor the depth of anaesthesia and brain activity, helping anaesthesiologists maintain an appropriate level of sedation.

f) Mapping Brain Activity: Advanced EEG techniques, such as event-related potentials (ERPs) and functional connectivity analysis, provide insights into brain activity associated with specific tasks, emotions, or sensory processing.

Q4a) Explain the chemical factors that affect respiration.

Ans) Respiration, the process of breathing, is influenced by several chemical factors, including:

a) Partial Pressure of Gases: The partial pressure of oxygen (PO2) and carbon dioxide (PCO2) in the blood and tissues plays a significant role in regulating respiration. Low PO2 and high PCO2 levels stimulate the respiratory center in the brain to increase breathing rate and depth.

b) Oxygen Saturation: Haemoglobin in red blood cells carries oxygen. If oxygen saturation in the blood decreases (e.g., in conditions like anaemia), it can lead to increased ventilation to compensate.

c) Carbon Dioxide Levels: High levels of carbon dioxide (hypercapnia) in the blood stimulate chemoreceptors in the medulla oblongata, leading to increased ventilation. Low carbon dioxide levels (hypocapnia) can reduce the drive to breathe.

d) Blood pH: Acidosis (low blood pH) and alkalosis (high blood pH) can affect respiration. Acidosis stimulates increased ventilation to eliminate excess carbon dioxide and reduce blood acidity, while alkalosis reduces ventilation to retain carbon dioxide.

e) Chemoreceptors: Specialized cells in the carotid and aortic bodies monitor blood gas levels. When these receptors detect changes in PO2 and PCO2, they signal the respiratory center to adjust breathing.

f) Hypoxia: Low oxygen levels in the blood (hypoxia) can stimulate breathing. Peripheral chemoreceptors in the carotid bodies are particularly sensitive to low oxygen levels.

g) Central Chemoreceptors: These receptors in the medulla are primarily sensitive to changes in PCO2 in the cerebrospinal fluid. Elevated PCO2 stimulates increased ventilation.

Q4b) What are gastrointestinal hormones? List any five gastrointestinal hormones and also give their functions.

Ans) Gastrointestinal Hormones: Cells in the digestive organs, such as the stomach and intestines, as well as other digestive organs, are responsible for the production of signalling molecules that are referred to as gastrointestinal hormones. They have a role in the control of a range of activities that take place within the digestive system, including digestion, absorption, and motility, which are all extremely significant functions.

Here are five gastrointestinal hormones and their functions:

a) Gastrin:

Function: Gastrin is produced by G cells in the stomach lining. It stimulates the secretion of gastric acid, which aids in digestion, and promotes the contraction of the stomach muscles to mix food.

b) Cholecystokinin (CCK):

Function: CCK is produced in the duodenum and jejunum of the small intestine. It stimulates the release of digestive enzymes from the pancreas and the contraction of the gallbladder to release bile, aiding in fat digestion and nutrient absorption.

c) Secretin:

Function: Secretin is produced in the duodenum. It stimulates the pancreas to secrete bicarbonate-rich pancreatic juice, which neutralizes stomach acid. It also reduces gastric motility.

d) Ghrelin:

Function: Ghrelin is produced in the stomach and plays a role in regulating appetite. It stimulates hunger and the intake of food. Ghrelin levels increase before meals and decrease after eating.

e) Motilin:

Function: Motilin is produced in the small intestine. It stimulates the migrating motor complex (a cyclical pattern of contractions) in the stomach and small intestine during fasting periods to aid in cleaning and emptying the digestive tract.

Q5a) What is the functional unit of kidney? Draw its structure and show its major parts.

Ans) The nephron is the functional unit of the kidney responsible for filtering blood, reabsorbing essential substances, and excreting waste products in the form of urine. It consists of several parts, including the renal corpuscle and the renal tubule. Here's a simplified diagram and the major parts of a nephron:

Major Parts of the Nephron

a) Renal Corpuscle:

1) Glomerulus: A tuft of capillaries that filters blood.

2) Bowman's Capsule: Surrounds the glomerulus and collects the filtrate.

b) Renal Tubule:

1) Proximal Convoluted Tubule (PCT): Reabsorbs water, ions, and glucose.

2) Loop of Henle: Establishes a concentration gradient in the medulla.

3) Distal Convoluted Tubule (DCT): Further reabsorption and secretion.

4) Collecting Duct: Receives urine from multiple nephrons and adjusts its composition.

Q5b) List the non- excretory functions of kidney.

Ans) While the primary role of the kidneys is excretion of waste products and maintenance of fluid and electrolyte balance, they also perform several non-excretory functions that are crucial for overall homeostasis and health.

Some of these functions include

a) Regulation of Blood Pressure: The kidneys play a vital role in regulating blood pressure by controlling blood volume through the renin-angiotensin-aldosterone system. They also influence blood pressure by adjusting peripheral vascular resistance.

b) Erythropoiesis Regulation: The kidneys produce and release erythropoietin, a hormone that stimulates the bone marrow to produce red blood cells (erythrocytes) when oxygen levels are low.

c) Acid-Base Balance: The kidneys help maintain the body's acid-base balance by excreting hydrogen ions and reabsorbing bicarbonate ions. They contribute to pH regulation in the blood.

d) Electrolyte Balance: The kidneys regulate the balance of electrolytes (sodium, potassium, calcium, etc.) in the body, ensuring that these ions are kept within appropriate concentration ranges.

e) Glucose Homeostasis: The kidneys can reabsorb glucose from the filtrate, maintaining glucose homeostasis in the blood. In cases of hyperglycaemia, excess glucose may be excreted in the urine.

f) Detoxification and Drug Metabolism: The kidneys can metabolize and excrete drugs and toxins from the body, contributing to detoxification processes.

g) Vitamin D Activation: The kidneys convert inactive vitamin D into its active form, which is necessary for calcium absorption and bone health.

h) Fluid Balance: The kidneys adjust urine volume and concentration to maintain overall fluid balance in the body.

Q6a) What is passive transport across cell membranes? Briefly explain any three types of passive transport.

Ans) Passive transport is a process by which substances move across a cell membrane without the expenditure of energy (ATP) by the cell. It occurs due to the natural movement of molecules from areas of higher concentration to areas of lower concentration.

Three common types of passive transport include

a) Diffusion: Diffusion is the movement of molecules (usually gases or small, nonpolar molecules) from an area of higher concentration to an area of lower concentration. It occurs until equilibrium is reached. For example, oxygen and carbon dioxide exchange in the lungs and the diffusion of glucose into cells.

b) Facilitated Diffusion: Facilitated diffusion involves the use of transport proteins (channel proteins or carrier proteins) to help specific molecules move across the cell membrane. It is used for molecules that cannot easily pass through the lipid bilayer, such as ions and large, polar molecules. Examples include the facilitated diffusion of glucose via glucose transporters and the movement of ions through ion channels.

c) Osmosis: Osmosis is a specialized form of diffusion that specifically involves the movement of water molecules across a selectively permeable membrane. Water moves from an area of lower solute concentration (higher water concentration) to an area of higher solute concentration (lower water concentration). Osmosis is critical for maintaining the osmotic balance of cells and is essential for life.

Q6b) Explain briefly the peripheral nervous system.

Ans) The peripheral nervous system is one of the two main divisions of the nervous system, with the other being the central nervous system (CNS). The PNS includes all the nerves and neural structures outside the brain and spinal cord (which make up the CNS). It plays several crucial roles in transmitting sensory information, controlling voluntary and involuntary movements, and connecting the body to the CNS.

The PNS is further divided into two main subdivisions:

a) Sensory (Afferent) Division: The sensory division of the PNS is responsible for transmitting sensory information from sensory receptors (e.g., in the skin, eyes, ears) to the CNS. These sensory neurons carry signals related to touch, temperature, pain, vision, hearing, taste, and smell, among others. This input is essential for the brain to perceive and respond to the external environment.

b) Motor (Efferent) Division: The motor division of the PNS carries signals from the CNS to muscles, glands, and other effectors to initiate motor responses. This division can be further subdivided into two components:

1) Somatic Nervous System (SNS): The SNS controls voluntary muscle movements and is responsible for conscious actions like walking, talking, and gesturing.

2) Autonomic Nervous System (ANS): The ANS controls involuntary actions and regulates functions like heart rate, digestion, respiratory rate, and glandular secretion. The ANS can be divided into the sympathetic and parasympathetic nervous systems, which have opposing effects to balance various physiological processes.

Q7a) Draw and label parts of a neuron.

Ans)

The neuron is a specialized and individual cell, which is also known as the nerve cell. A group of neurons forms a nerve.

a) Dendrites–A branch-like structure that functions by receiving messages from other neurons and allow the transmission of messages to the cell body.

b) Cell Body–Each neuron has a cell body with a nucleus, Golgi apparatus, endoplasmic reticulum, mitochondria, and other components.

c) Axon–Axon is a tube-like structure that functions by carrying an electrical impulse from the cell body to the axon terminals for passing the impulse to another neuron.

d) Synapse– This structure functions by permitting the entry of a neuron to move an electrical or chemical signal from one neuron to another neuron.

Q7b) What is a neurotransmitter. List the characteristics of a neurotransmitter. Name any two neurotransmitters.

Ans) A neurotransmitter is a chemical compound that serves as a signaling molecule in the nervous system, transmitting signals between nerve cells (neurons), or from neurons to target cells such as muscles or other neurons. Neurotransmitters are crucial for communication within the nervous system, facilitating the transmission of electrical impulses (action potentials) across synapses, the junctions between neurons.

Characteristics of Neurotransmitters

a) Synthesis and Release: Neurotransmitters are synthesized within neurons and stored in vesicles at the nerve terminals. When an action potential reaches the terminal, neurotransmitters are released into the synaptic cleft.

b) Binding to Receptors: Neurotransmitters bind to specific receptor molecules on the postsynaptic cell, which can be another neuron, a muscle cell, or a gland cell. This binding initiates a cellular response in the target cell.

c) Rapid Action: Neurotransmitters produce rapid, short-lived effects. Once they have triggered a response in the postsynaptic cell, they are typically rapidly degraded or reabsorbed to terminate their action.

d) Specificity: Different types of neurotransmitters have distinct effects and interact with specific receptor types. This specificity allows for a wide range of responses in the nervous system.

e) Modulation of Neuronal Activity: Neurotransmitters can either excite or inhibit the postsynaptic neuron, contributing to the regulation of neuronal activity and the transmission of signals.

f) Feedback Mechanisms: Some neurotransmitters can also act as neuromodulators, influencing the sensitivity of both pre- and postsynaptic neurons, which can have longer-lasting effects on neural circuits.

g) Reuptake and Degradation: After transmitting their signal, neurotransmitters are either taken back up into the presynaptic neuron through reuptake transporters or broken down by enzymes to terminate their action.

h) Diverse Types: There are numerous neurotransmitters in the nervous system, each with its specific functions and receptors. Examples include acetylcholine, dopamine, serotonin, norepinephrine, glutamate, and gamma-aminobutyric acid (GABA).

Two Neurotransmitters

a) Dopamine: Dopamine is a neurotransmitter that plays a role in various functions, including movement control, reward and motivation, mood regulation, and cognitive processes. Dysregulation of dopamine has been associated with conditions like Parkinson's disease and schizophrenia.

b) Serotonin: Serotonin is a neurotransmitter that is involved in mood regulation, sleep, appetite, and emotional well-being. It is associated with conditions like depression, anxiety, and various mood disorders.

Q8a) Briefly explain any three disorders of image formation. How are they corrected?

Ans) Disorders of Image Formation and Their Correction:

a) Myopia (Nearsightedness):

1) Disorder: Myopia is a vision disorder in which distant objects appear blurry, while close objects can be seen clearly. It occurs when the eyeball is too long or the cornea has excessive curvature, causing light to focus in front of the retina rather than directly on it.

2) Correction: Myopia can be corrected with concave lenses (glasses or contact lenses) that diverge incoming light, allowing it to focus correctly on the retina.

b) Hyperopia (Farsightedness):

1) Disorder: Hyperopia is a vision disorder in which close objects are seen less clearly, while distant objects are relatively clear. It typically occurs when the eyeball is too short or the cornea is too flat, causing light to focus behind the retina.

2) Correction: Hyperopia can be corrected with convex lenses (glasses or contact lenses) that converge incoming light, allowing it to focus properly on the retina.

c) Astigmatism:

1) Disorder: Astigmatism is a vision disorder characterized by irregularly shaped corneas or lenses, leading to distorted or blurred vision at all distances. It occurs because the eye has multiple focal points for light rays.

2) Correction: Astigmatism is corrected with cylindrical lenses that have different refractive power in different meridians, compensating for the irregular shape of the eye's optics.

Q8b) List the different organs involved in taste perception. Explain briefly the mechanism of taste perception

Ans) Taste perception, or gustation, involves several organs and processes.

Organs Involved

Taste Buds: Taste buds are specialized sensory organs located primarily on the tongue, but they can also be found on the soft palate, the back of the throat, and the epiglottis.

Mechanism of Taste Perception

a) Taste Receptors: Taste perception begins with taste receptors located on the microvilli of taste cells within taste buds. Taste receptors are specialized proteins that bind to specific molecules in the food we eat. There are five primary taste qualities: sweet, sour, bitter, salty, and umami (savoury).

b) Taste Transduction: When a food molecule binds to a taste receptor, it initiates a signal that is transmitted to sensory nerve fibres through taste cells. Different taste receptors are activated based on the specific molecule's chemical properties.

c) Transmission to the Brain: Sensory nerve fibres transmit the taste signals to the brain, specifically to the gustatory cortex, which is responsible for processing taste information.

d) Perception of Taste: The brain integrates the signals from different taste receptors to create the perception of taste. This perception is influenced by the combination of taste qualities in the food, the aroma (which is detected by the olfactory system), and other factors.

e) Taste Modification and Adaptation: Taste perception can be influenced by factors such as temperature, texture, and personal preference. Additionally, the sense of taste can adapt over time, leading to a decreased perception of a particular taste when it is continuously exposed to the same stimulus. For example, a food that tastes very sweet initially may taste less sweet if consumed repeatedly.

f) Gustatory Disorders: Gustatory disorders can affect taste perception. Anosmia is the loss of the sense of smell, which can impair the perception of flavour. Ageusia is the loss of the sense of taste, resulting in the inability to detect any taste sensations. Dysgeusia is a distortion of the sense of taste, causing an unpleasant taste perception. Taste disorders can result from various medical conditions, medications, or neurological issues.

Q9a)What is haemostasis? Enumerate the disorders of haemostasis. Give an example of each.

Ans) Haemostasis is the physiological process that prevents excessive bleeding and promotes the formation of blood clots to maintain blood within the circulatory system. It involves a delicate balance between pro-coagulant factors that promote clot formation and anti-coagulant factors that prevent excessive clotting.

Haemostasis occurs in three main phases:

a) Vasoconstriction: When a blood vessel is injured, the smooth muscle in the blood vessel wall constricts to reduce blood flow and minimize bleeding.

b) Primary Haemostasis: Platelets, which are cell fragments in the blood, adhere to the site of injury and become activated to form a platelet plug, temporarily stopping bleeding.

c) Secondary Haemostasis: A cascade of enzymatic reactions leads to the formation of a stable blood clot. This involves the conversion of fibrinogen into fibrin, which reinforces the platelet plug.

Disorders of Haemostasis and Examples

a) Haemophilia:

1) Disorder: Haemophilia is a genetic disorder characterized by a deficiency of clotting factors, typically factor VIII (haemophilia A) or factor IX (haemophilia B). This leads to prolonged bleeding and poor clot formation.

2) Example: Haemophilia A is exemplified by a deficiency of factor VIII.

b) Thrombocytopenia:

1) Disorder: Thrombocytopenia is a condition in which there is a low platelet count in the blood, leading to impaired primary haemostasis and increased bleeding tendencies.

2) Example: Immune thrombocytopenic purpura (ITP) is an autoimmune disorder causing platelet destruction.

c) Von Willebrand Disease:

1) Disorder: Von Willebrand disease is a genetic disorder characterized by a deficiency or dysfunction of von Willebrand factor, which plays a crucial role in platelet adhesion. This leads to impaired platelet plug formation.

2) Example: Von Willebrand disease can manifest in various forms with varying degrees of severity.

Q9b) List the two major hormones secreted by each of the following glands and explain their physiological effects:

(i) Thyroid gland

(ii) Posterior Pituitary

Ans) The thyroid gland produces and releases two major hormones:

a) Thyroxine (T4): Thyroxine is the primary hormone secreted by the thyroid gland. It plays a key role in regulating the body's metabolic rate and overall energy balance. T4 is converted into its more active form, triiodothyronine (T3), in various tissues. T3 and T4 influence the function of nearly every cell in the body, affecting growth, development, and metabolic processes.

b) Triiodothyronine (T3): Triiodothyronine is a more potent thyroid hormone produced in smaller quantities than T4. It is essential for various physiological functions, including temperature regulation, heart rate, and the regulation of metabolic processes. T3 acts by binding to specific receptors on target cells and modulating gene expression to regulate metabolic activity.

Physiological Effects

The thyroid hormones (T3 and T4) have broad-ranging physiological effects, including:

a) Increasing the basal metabolic rate and energy production.

b) Regulating body temperature and heat production.

c) Influencing growth and development, especially in children.

d) Promoting the function of the cardiovascular system, including heart rate and blood pressure regulation.

e) Aiding in the maintenance of healthy skin, hair, and nails.

f) Facilitating digestion and metabolism of carbohydrates, proteins, and fats.

Two Major Hormones from Posterior Pituitary

The posterior pituitary does not synthesize hormones, but stores and releases two important hormones produced by the hypothalamus:

a) Oxytocin: Oxytocin is involved in uterine contractions during labor and plays a crucial role in lactation by stimulating milk ejection from the mammary glands. It also contributes to social bonding, emotional attachment, and trust.

b) Vasopressin (Antidiuretic Hormone, ADH): Vasopressin helps regulate water balance in the body by increasing water reabsorption in the kidneys, reducing urine output, and constricting blood vessels to raise blood pressure when needed.

Q10a) Name the female reproductive hormones and the target tissues they act on?

Ans) Female Reproductive Hormones and Their Target Tissues:

a) Estrogen: Estrogen is a group of hormones that includes estradiol, estrone, and estriol. They are primarily produced by the ovaries.

1) Target Tissues:

i) Ovaries: Estrogen helps regulate the menstrual cycle and the development of ovarian follicles.

ii) Uterus: Estrogen thickens the endometrial lining in preparation for potential embryo implantation.

iii) Breasts: Estrogen plays a role in breast development.

iv) Secondary Sexual Characteristics: Estrogen influences the development of secondary sexual characteristics, such as body hair distribution and fat distribution.

b) Progesterone: Progesterone is mainly produced by the corpus luteum in the ovaries and later by the placenta during pregnancy.

1) Target Tissues:

i) Uterus: Progesterone is crucial for maintaining the endometrial lining, preparing it for embryo implantation and preventing its shedding.

ii) Mammary Glands: Progesterone contributes to the development of milk-producing glands during pregnancy.

iii) Follicle-Stimulating Hormone (FSH): FSH is produced by the anterior pituitary gland.

iv) Target Tissues:

v) Ovaries: FSH stimulates the growth and development of ovarian follicles in the ovaries.

c) Luteinizing Hormone (LH): LH is produced by the anterior pituitary gland.

1) Target Tissues:

i) Ovaries: LH triggers ovulation and the formation of the corpus luteum.

ii) Human Chorionic Gonadotropin (hCG): hCG is produced by the placenta during pregnancy.

iii) Target Tissues:

iv) Ovaries: hCG helps maintain the corpus luteum, which continues to produce progesterone to support the uterine lining during early pregnancy.

10b) Enlist the male reproductive organs. Write a review of the inflammatory infections affecting these organs.

Ans) Male reproductive organs include:

a) Testes: The primary male reproductive organs responsible for producing sperm and the hormone testosterone.

b) Epididymis: A coiled tube located on the surface of the testes where sperm mature and are stored.

c) Vas Deferens (Ductus Deferens): A muscular tube that carries mature sperm from the epididymis to the urethra.

d) Seminal Vesicles: Glandular structures that produce a significant portion of seminal fluid, contributing fructose, prostaglandins, and other substances to semen.

e) Prostate Gland: A gland that produces a milky fluid that enhances sperm motility and viability.

f) Bulbourethral (Cowper's) Glands: Glands that produce a clear, lubricating fluid that neutralizes urine residues in the urethra.

Inflammatory Infections Affecting Male Reproductive Organs

a) Epididymitis: Epididymitis is the inflammation of the epididymis, often due to a bacterial infection, such as a urinary tract infection or sexually transmitted infection (STI) like chlamydia or gonorrhoea. Symptoms may include testicular pain, swelling, and fever.

b) Orchitis: Orchitis is the inflammation of one or both testicles, often caused by viral infections like mumps or bacterial infections. It may lead to testicular pain, swelling, and fever.

c) Prostatitis: Prostatitis is the inflammation of the prostate gland, usually due to bacterial infection. It can cause discomfort or pain in the pelvic area, frequent urination, and pain during urination.

d) Urethritis: Urethritis is the inflammation of the urethra, often caused by bacterial infections, including STIs. It can result in painful urination and discharge from the penis.

Section B – OTQ (Objective Type Questions)

Q1)Define the following:

i) Mitosis

Ans) Mitosis is the process that a single eukaryotic cell will go through in order to divide into two daughter cells that are genetically identical to each other. This process is necessary when the cell needs to divide. Eukaryotic cells go through a process called mitosis when they divide. This technique is important for the proliferation of somatic cells in the body, which are cells that do not participate in reproduction, as well as for the repair and maintenance of tissues. It is a process that takes place in somatic cells and results in the development of two diploid cells that have the same number of chromosomes as the original cell. This process is known as mitosis. Meiosis is the name given to this particular process.

ii) Aplastic Anaemia

Ans) Aplastic anaemia is an uncommon and serious medical disorder that is characterised by a deficit of red blood cells, white blood cells, and platelets in the blood. This shortfall can be caused by a number of different factors, including genetic mutations or infections. This insufficiency may present itself in a variety of different ways depending on the individual. This deficiency may present itself in any one of the three types of blood cells, in all of them at the same time, or in any combination of the three at any given time. Some of the symptoms of this sickness include fatigue, weakness, an increased risk of infection, and problems with bleeding. Additionally, the danger of infection is increased. This condition arises when the bone marrow is unable to create a sufficient number of blood cells, which in turn can lead to the sickness that is the subject of this article.

iii) Interleukin-1

Ans) Interleukin-1 (IL-1) is a sort of cytokine, which is a type of signalling molecule that is produced by immune cells. These cells are responsible for the production of IL-1. Cytokines are proteins that play important roles in a number of different biological processes. IL-1 plays a role in the regulation of both the immune system's inflammatory response as well as the immune system's own inflammatory response. It is engaged in the process of beginning and directing the body's defence systems against infections as well as damage to the tissues. These mechanisms protect the body from both types of damage. There are two basic varieties, IL-1 and IL-1, and both of these forms play a part in the immune response as well as the inflammatory response. IL-1 is also involved in the response.

iv) Emphysema

Ans) Emphysema is a progressive and chronic lung condition that makes it progressively difficult to breathe over the course of its progression. This disease mostly impacts the air sacs that are found in the lungs; these sacs are also referred to as alveoli. The majority of cases of the syndrome are brought on by an extended exposure to irritants like cigarette smoke or passive smoking, which can last for a long period of time. Because emphysema causes the alveoli to degenerate, the lungs become less flexible, breathing becomes more difficult, and the lungs' capacity to exchange oxygen is diminished. These symptoms are all direct results of emphysema.

v) Nephrotic Syndrome

Ans) Nephrotic syndrome is a condition that affects the kidneys and is distinguished by the abnormal discharge of a significant amount of protein into the urine. This abnormal discharge is the defining feature of the condition. Nephrotic syndrome is another name for what is commonly known as nephrotic condition. In many cases, the primary cause of this illness is damage to the glomeruli, which are very small filtering units present in the kidneys. Glomeruli are sometimes referred to as the kidney's filters. Edema, which is also known as swelling, is one of the most common symptoms associated with this ailment. Additionally, a considerable quantity of protein might be observed in the patient's urine, despite the fact that the blood protein level may be low. These are some of the other symptoms. Edema most frequently occurs in the eyes, hands, and feet. It is also common in the face.

Q2) Give the functions/role of the following structure/organs in our body:

i) Adrenal gland

Ans) The adrenal glands are responsible for producing hormones, including adrenaline and cortisol, which play essential roles in the body's stress response, metabolism, blood pressure regulation, and immune system function.

ii) ECG

Ans) An ECG is a diagnostic test that records the electrical activity of the heart. It is used to assess the heart's rhythm, detect irregularities, and diagnose conditions such as arrhythmias, heart attacks, and other cardiac disorders.

iii) Pleura

Ans) The pleura is a double-layered membrane surrounding the lungs and lining the chest cavity. It plays a crucial role in protecting the lungs, reducing friction during breathing, and helping to maintain lung expansion and recoil.

iv) Secretin

Ans) Secretin is a hormone produced in the small intestine and released into the bloodstream. Its primary role is to regulate the pH of the digestive system by stimulating the release of bicarbonate from the pancreas to neutralize stomach acid.

v) Neurotransmitters

Ans) Neurotransmitters are chemical messengers that transmit signals between nerve cells (neurons) in the nervous system. They play a central role in communication between neurons and are essential for functions such as memory, mood, muscle control, and more.

vi) Purkinje fibres

Ans) Purkinje fibres are specialized cardiac muscle fibres responsible for transmitting electrical impulses through the heart, regulating heart rhythm, and coordinating the contraction of the heart's ventricles.

vii) Temporal lobe

Ans) The temporal lobe is a region of the brain involved in various functions, including auditory processing, memory, language, and emotion. It is also associated with the processing of sensory input and recognition of faces.

viii) Myopia

Ans) Myopia, commonly known as near-sightedness, is a refractive error of the eye. It causes difficulty in seeing distant objects clearly, as the light entering the eye focuses in front of the retina instead of on it.

ix) Small intestine

Ans) The small intestine is a vital part of the digestive system responsible for the absorption of nutrients (such as sugars, amino acids, and fatty acids) from digested food. It plays a central role in nutrient absorption and the breakdown of food particles.

x) Ageusia

Ans) Ageusia refers to the loss or absence of the sense of taste. It can result from various medical conditions or medications and can significantly affect a person's ability to detect and enjoy flavours in food and beverages.

Q3) Match the items in List I with items in List II:

Ans)