60 short questions with answers on Human Physiology (Chapter wise)
a. Digestion and Absorption
1. Q: Name the four main layers of the alimentary canal wall.
A: The four main layers are serosa, muscularis, submucosa, and mucosa.
2. Q: What is the role of peristalsis in digestion?
A: Peristalsis is the rhythmic contraction and relaxation of the smooth muscles in the alimentary canal, propelling food along the digestive tract.
3. Q: Briefly explain the function of bile in digestion.
A: Bile, produced by the liver and stored in the gallbladder, emulsifies fats in the small intestine, breaking large fat globules into smaller ones, increasing the surface area for lipase action.
4. Q: What is the approximate calorific value of 1 gram of carbohydrates?
A: Approximately 4 Kcal/g.
5. Q: Define egestion.
A: Egestion is the process of eliminating undigested food materials (feces) from the body through the anus.
6. Q: Differentiate between indigestion and constipation.
A: Indigestion refers to a feeling of fullness, pain, or discomfort in the upper abdomen, often due to inadequate enzyme secretion, anxiety, or overeating. Constipation is infrequent and difficult defecation due to irregular bowel movements or insufficient fiber intake.
7. Q: What is PEM? Name one disorder caused by it.
A: PEM stands for Protein Energy Malnutrition. Kwashiorkor or Marasmus are disorders caused by it.
8. Q: What is jaundice? Which organ is primarily affected?
A: Jaundice is a condition characterized by yellowing of the skin and eyes due to the accumulation of bile pigments in the blood. The liver is primarily affected.
9. Q: Name two enzymes involved in protein digestion and their sites of action.
A: Pepsin (in the stomach) and Trypsin (in the small intestine).
10. Q: How are fats absorbed in the small intestine?
A: Fats are absorbed as micelles into the intestinal mucosal cells, where they are re-formed into chylomicrons and transported into the lacteals (lymphatic capillaries).
b. Breathing and Respiration
11. Q: Name the respiratory organs in insects and amphibians.
A: Insects use tracheal system; amphibians can use skin (cutaneous), buccal cavity, and lungs.
12. Q: List the main parts of the human respiratory system.
A: Nostrils, pharynx, larynx, trachea, bronchi, bronchioles, and lungs (with alveoli).
13. Q: Briefly explain the role of diaphragm in breathing.
A: During inspiration, the diaphragm contracts and flattens, increasing the volume of the thoracic cavity. During expiration, it relaxes and arches upwards, decreasing the volume.
14. Q: What is tidal volume?
A: Tidal volume is the volume of air inspired or expired during a normal respiration. (Approx. 500 mL).
15. Q: How are oxygen and carbon dioxide exchanged at the alveolar level?
A: Oxygen diffuses from the alveoli into the blood (due to higher partial pressure in alveoli), and carbon dioxide diffuses from the blood into the alveoli (due to higher partial pressure in blood).
16. Q: Define vital capacity.
A: Vital capacity is the maximum volume of air a person can breathe in after a forced expiration, or breathe out after a forced inspiration.
17. Q: What is asthma?
A: Asthma is a chronic respiratory disorder characterized by inflammation and narrowing of the airways, leading to difficulty in breathing, wheezing, and coughing.
18. Q: Explain emphysema briefly.
A: Emphysema is a chronic disorder in which alveolar walls are damaged, leading to a decrease in the respiratory surface area. It is often caused by cigarette smoking.
19. Q: Give an example of an occupational respiratory disorder.
A: Silicosis or Asbestosis are examples.
20. Q: How is breathing regulated in humans?
A: Breathing is primarily regulated by the respiratory rhythm center in the medulla oblongata of the brain, influenced by chemoreceptors sensitive to CO2 and H+ concentrations.
c. Body fluids and Circulation
21. Q: Name the three main types of blood cells.
A: Erythrocytes (RBCs), Leukocytes (WBCs), and Platelets.
22. Q: What are the universal donor and universal recipient blood groups?
A: Universal donor: O negative; Universal recipient: AB positive.
23. Q: Briefly describe the process of blood coagulation.
A: Blood coagulation is a complex process involving a cascade of enzymatic reactions, initiated by tissue injury, leading to the formation of a fibrin clot that traps blood cells and seals the wound.
24. Q: What is lymph and what is its primary function?
A: Lymph is a colorless fluid containing lymphocytes and less protein than blood plasma. Its primary function is to transport nutrients, oxygen, and hormones to tissues, and to carry waste products away, as well as to play a role in the immune system.
25. Q: Draw a simple flow chart showing the path of blood in double circulation.
A: Right Atrium → Right Ventricle → Lungs → Left Atrium → Left Ventricle → Body → Right Atrium.
26. Q: What is cardiac output?
A: Cardiac output is the volume of blood pumped by the heart (specifically, by each ventricle) per minute. (Cardiac output = Heart rate × Stroke volume).
27. Q: What does an ECG measure?
A: ECG (Electrocardiogram) measures the electrical activity of the heart during a cardiac cycle.
28. Q: Define hypertension.
A: Hypertension is persistently high blood pressure, where the systolic pressure is 140 mmHg or higher and/or the diastolic pressure is 90 mmHg or higher.
29. Q: What is angina pectoris?
A: Angina pectoris is a symptom of acute chest pain that occurs when the heart muscle receives insufficient oxygen, often due to reduced blood flow through the coronary arteries.
30. Q: Differentiate between coronary artery disease and heart failure.
A: Coronary artery disease (CAD) refers to conditions where the coronary arteries become narrowed or blocked, usually by atherosclerosis, reducing blood flow to the heart muscle. Heart failure is a state where the heart is not pumping blood effectively enough to meet the body's metabolic needs.
d. Excretory products and their elimination
31. Q: Define ammonotelism. Give an example of an ammonotelic animal.
A: Ammonotelism is the mode of excretion where ammonia is the primary nitrogenous waste product. Aquatic amphibians or bony fishes are examples.
32. Q: Name the main excretory organ in humans and its functional unit.
A: The main excretory organ is the kidney, and its functional unit is the nephron.
33. Q: Briefly explain the process of ultrafiltration in urine formation.
A: Ultrafiltration occurs in the glomerulus, where blood is filtered under pressure, forcing water and small solutes from the blood into Bowman's capsule, while retaining large molecules like proteins and blood cells.
34. Q: What is osmoregulation?
A: Osmoregulation is the process by which organisms maintain the balance of water and salt concentrations (osmotic pressure) in their body fluids.
35. Q: What is the role of ADH (Antidiuretic Hormone) in kidney function?
A: ADH increases the permeability of the collecting ducts and distal convoluted tubule to water, promoting water reabsorption and reducing urine volume, thus preventing water loss.
36. Q: What is diabetes insipidus?
A: Diabetes insipidus is a disorder characterized by excessive thirst and excretion of large amounts of dilute urine, due to insufficient production of ADH or the kidneys' inability to respond to ADH.
37. Q: What is uraemia?
A: Uraemia is a condition where there is an accumulation of excessive urea and other nitrogenous waste products in the blood due to kidney failure.
38. Q: What are renal calculi?
A: Renal calculi (kidney stones) are hardened masses of mineral and acid salts that form in the kidneys and can cause pain and blockage.
39. Q: How does dialysis (artificial kidney) help a patient with renal failure?
A: Dialysis is a medical procedure that filters waste products and excess fluid from the blood when the kidneys are unable to do so, mimicking the function of healthy kidneys.
40. Q: Name two other organs that play a minor role in excretion.
A: Liver (breaks down metabolic waste, secretes bile) and Skin (excretes sweat containing water, salts, urea, lactic acid).
e. Locomotion and Movement
41. Q: Name the three types of movement exhibited by human cells.
A: Ciliary movement, flagellar movement, and muscular movement.
42. Q: Name the two main contractile proteins in skeletal muscle.
A: Actin and Myosin.
43. Q: What is the basic functional unit of a muscle fiber?
A: Sarcomere.
44. Q: Briefly explain the "sliding filament theory" of muscle contraction.
A: The sliding filament theory states that muscle contraction occurs as the thin (actin) filaments slide past the thick (myosin) filaments, shortening the sarcomere, without the filaments themselves shortening.
45. Q: List two important functions of the human skeletal system.
A: Support and protection of internal organs, and providing sites for muscle attachment for movement.
46. Q: What is a joint? Name one type of immovable joint.
A: A joint is a point where two or more bones meet. Sutures in the skull are an example of an immovable (fibrous) joint.
47. Q: What is Myasthenia Gravis?
A: Myasthenia Gravis is an autoimmune disorder that affects the neuromuscular junction, leading to progressive weakness and fatigue of skeletal muscles.
48. Q: Define Arthritis.
A: Arthritis is a condition characterized by inflammation of joints, causing pain, stiffness, and sometimes swelling.
49. Q: What is Osteoporosis?
A: Osteoporosis is a disease where bones become weak and brittle, often due to a decrease in bone density, making them susceptible to fractures.
50. Q: What is Gout?
A: Gout is a type of arthritis caused by the accumulation of uric acid crystals in the joints, leading to severe pain, redness, and tenderness, most commonly in the big toe.
f. Neural Control and Coordination
51. Q: Differentiate between a neuron and a nerve.
A: A neuron is a single nerve cell, the structural and functional unit of the nervous system. A nerve is a bundle of axons (nerve fibers) belonging to many neurons, wrapped in connective tissue.
52. Q: Name the two main divisions of the human central nervous system (CNS).
A: Brain and Spinal Cord.
53. Q: What is a synapse?
A: A synapse is the junction between two neurons or between a neuron and an effector cell (e.g., muscle cell), where nerve impulses are transmitted.
54. Q: Briefly explain reflex action.
A: A reflex action is a sudden, involuntary, and automatic response to a stimulus, without conscious thought or control from the brain, mediated by a reflex arc.
55. Q: Name the three main parts of the human brain.
A: Forebrain, Midbrain, and Hindbrain.
56. Q: Which part of the brain is responsible for maintaining body balance and posture?
A: Cerebellum.
57. Q: What is the function of the pupil in the human eye?
A: The pupil regulates the amount of light entering the eye by constricting in bright light and dilating in dim light.
58. Q: Name the three ossicles of the middle ear.
A: Malleus (hammer), Incus (anvil), and Stapes (stirrup).
59. Q: What is the primary function of the Eustachian tube?
A: The Eustachian tube connects the middle ear to the pharynx and helps equalize pressure on either side of the eardrum.
60. Q: Briefly explain the generation of a nerve impulse (action potential).
A: A nerve impulse (action potential) is generated by a rapid change in the electrical potential across the neuron's membrane, involving the sequential opening and closing of voltage-gated ion channels (Na+ and K+ channels), leading to depolarization and repolarization.
