Chapter 22: Chemical Coordination and Integration – MCQs
MCQs on Human Physiology — Chemical Coordination & Integration, tailored for NEET & CBSE. Each question has four options (a–d).
Human Physiology — Chemical Coordination & Integration
Part 1 — Questions 1–25
Q1. The primary endocrine gland that links the nervous system with the endocrine system is the:
a) Thyroid gland
b) Adrenal medulla
c) Pituitary gland (via hypothalamus)
d) Pancreas
Answer: c) Pituitary gland (via hypothalamus)
- a) Thyroid gland — major endocrine gland but receives regulatory signals from pituitary, not the main link to nervous system.
- b) Adrenal medulla — receives direct sympathetic innervation (neuroendocrine), but not the primary integrator.
- c) Pituitary (via hypothalamus) — correct. The hypothalamus (neural) controls pituitary hormone release, making the hypothalamo-pituitary axis the main neuro-endocrine link.
- d) Pancreas — endocrine & exocrine functions, regulated metabolically and hormonally, not the major neural–endocrine interface.
Q2. Which hormone is secreted by the posterior pituitary?
a) Growth hormone (GH)
b) Thyroid-stimulating hormone (TSH)
c) Oxytocin
d) Prolactin
Answer: c) Oxytocin
- a) GH — secreted by anterior pituitary.
- b) TSH — anterior pituitary tropic hormone.
- c) Oxytocin — correct. Posterior pituitary stores and releases oxytocin (and ADH) produced in hypothalamus.
- d) Prolactin — anterior pituitary hormone.
Q3. Which of the following hormones increases blood glucose concentration?
a) Insulin
b) Glucagon
c) Aldosterone
d) Calcitonin
Answer: b) Glucagon
- a) Insulin — decreases blood glucose by promoting uptake and storage.
- b) Glucagon — correct. Secreted by pancreatic α-cells; stimulates glycogenolysis and gluconeogenesis raising blood glucose.
- c) Aldosterone — regulates Na⁺/K⁺ balance, not primary glucose control.
- d) Calcitonin — involved in calcium homeostasis.
Q4. Which hormone uses cyclic AMP (cAMP) as a second messenger in many target cells?
a) Thyroid hormone (T3/T4)
b) Steroid hormones (e.g., cortisol)
c) Epinephrine acting on β-adrenergic receptors
d) Thyrotropin-releasing hormone (TRH) acting via nuclear receptors
Answer: c) Epinephrine acting on β-adrenergic receptors
- a) Thyroid hormones — lipid-soluble; act via nuclear receptors altering gene transcription.
- b) Steroid hormones — intracellular receptor mechanism (not cAMP).
- c) Epinephrine (β receptors) — correct. β-adrenergic receptor activation stimulates adenylate cyclase → ↑cAMP (a common second messenger).
- d) TRH — acts via G-protein pathways in some cells but not via nuclear receptors; the option is misleading.
Q5. Which cell type secretes parathyroid hormone (PTH)?
a) Chief (principal) cells of parathyroid gland
b) Oxyphil cells of parathyroid gland
c) C cells of thyroid
d) Follicular cells of thyroid
Answer: a) Chief (principal) cells of parathyroid gland
- a) Chief cells — correct. They synthesize and secrete PTH, which increases blood Ca²⁺.
- b) Oxyphil cells — present in parathyroid, function unclear, not main PTH producers.
- c) C cells (parafollicular) — in thyroid; secrete calcitonin (lowers Ca²⁺).
- d) Follicular cells — thyroid hormone (T3/T4) producers.
Q6. A prolonged excess of cortisol causes:
a) Addison’s disease
b) Cushing’s syndrome
c) Graves’ disease
d) Myxedema
Answer: b) Cushing’s syndrome
- a) Addison’s disease — adrenal insufficiency (low cortisol).
- b) Cushing’s syndrome — correct. Chronic cortisol excess causes central obesity, muscle wasting, hyperglycemia, hypertension.
- c) Graves’ disease — hyperthyroidism due to autoantibodies.
- d) Myxedema — severe hypothyroidism.
Q7. Which hormone directly increases renal water reabsorption?
a) Aldosterone
b) Atrial natriuretic peptide (ANP)
c) Antidiuretic hormone (ADH / vasopressin)
d) Parathyroid hormone (PTH)
Answer: c) Antidiuretic hormone (ADH / vasopressin)
- a) Aldosterone — increases Na⁺ reabsorption (water follows), but ADH directly increases water permeability via aquaporins.
- b) ANP — promotes natriuresis and diuresis (opposes water retention).
- c) ADH — correct. Acts on collecting ducts to insert aquaporin-2 channels → ↑water reabsorption and urine concentration.
- d) PTH — regulates Ca²⁺/PO₄³⁻, not direct water reabsorption.
Q8. Which hormone stimulates milk ejection (milk let-down) during breastfeeding?
a) Prolactin
b) Oxytocin
c) Estrogen
d) Progesterone
Answer: b) Oxytocin
- a) Prolactin — stimulates milk production (synthesis), not the ejection reflex.
- b) Oxytocin — correct. Released from posterior pituitary; causes myoepithelial cell contraction → milk ejection.
- c/d) Estrogen/progesterone — regulate mammary development and pregnancy; not primary for ejection.
Q9. Which statement about steroid hormones is TRUE?
a) They bind to cell-surface receptors and use cAMP as a second messenger.
b) They are water-soluble and circulate freely in plasma.
c) They are lipophilic, cross cell membranes, and act via intracellular receptors that modulate gene transcription.
d) They are stored in secretory vesicles and released by exocytosis like peptide hormones.
Answer: c) They are lipophilic, cross cell membranes, and act via intracellular receptors that modulate gene transcription.
- a) Cell-surface + cAMP — typical for peptide/amine hormones, not steroid hormones.
- b) Water-soluble free circulation — steroid hormones are bound to carrier proteins in blood.
- c) Lipophilic & intracellular action — correct. Steroids (e.g., cortisol, aldosterone, sex steroids) act on nuclear receptors altering transcription.
- d) Stored in vesicles — steroid hormones are synthesized on demand and diffuse out, not stored in vesicles.
Q10. Which pituitary hormone stimulates thyroid hormone production?
a) ACTH (adrenocorticotropic hormone)
b) TSH (thyroid-stimulating hormone)
c) LH (luteinizing hormone)
d) GH (growth hormone)
Answer: b) TSH (thyroid-stimulating hormone)
- a) ACTH — stimulates adrenal cortex cortisol production.
- b) TSH — correct; produced by anterior pituitary; stimulates thyroid follicular cells to synthesize T3/T4.
- c) LH — gonadal steroid stimulation.
- d) GH — growth effects, IGF-1 stimulation.
Q11. Which of the following increases bone resorption and raises blood calcium?
a) Calcitonin
b) Parathyroid hormone (PTH)
c) Insulin
d) Somatostatin
Answer: b) Parathyroid hormone (PTH)
- a) Calcitonin — lowers blood calcium by inhibiting osteoclasts.
- b) PTH — correct; increases osteoclast activity indirectly, increases renal Ca²⁺ reabsorption and activates vitamin D (calcitriol) → ↑intestinal Ca²⁺ absorption.
- c/d) Insulin/somatostatin — not primary regulators of Ca²⁺.
Q12. Which hormone(s) is/are secreted from the adrenal medulla?
a) Cortisol and aldosterone
b) Epinephrine and norepinephrine
c) ACTH and MSH
d) Insulin and glucagon
Answer: b) Epinephrine and norepinephrine
- a) Cortisol/aldosterone — produced by adrenal cortex.
- b) Epinephrine & norepinephrine — correct; adrenal medulla secretes catecholamines (neuroendocrine chromaffin cells).
- c) ACTH/MSH — pituitary hormones.
- d) Insulin/glucagon — pancreatic islet hormones.
Q13. Which of the following conditions is characterized by autoantibodies that stimulate the TSH receptor causing hyperthyroidism?
a) Hashimoto’s thyroiditis
b) Graves’ disease
c) Cretinism
d) Myxedema
Answer: b) Graves’ disease
- a) Hashimoto’s — autoimmune hypothyroidism with destructive antibodies.
- b) Graves’ disease — correct; stimulating TSH receptor antibodies → ↑T3/T4, diffuse goiter, ophthalmopathy.
- c) Cretinism — congenital hypothyroidism causing developmental delay.
- d) Myxedema — severe hypothyroidism in adults.
Q14. Which hormone increases blood Na⁺ reabsorption and K⁺ secretion in the distal nephron?
a) ADH (vasopressin)
b) Aldosterone
c) ANP (atrial natriuretic peptide)
d) Parathyroid hormone
Answer: b) Aldosterone
- a) ADH — increases water reabsorption (collecting duct), minimal direct effect on Na⁺ channels.
- b) Aldosterone — correct; mineralocorticoid from adrenal cortex upregulates ENaC and Na⁺/K⁺-ATPase → Na⁺ retention and K⁺ excretion.
- c) ANP — promotes Na⁺ excretion (opposes aldosterone).
- d) PTH — acts on Ca²⁺/PO₄³⁻, not main Na⁺/K⁺ regulator.
Q15. Diabetes insipidus is caused by deficiency or resistance to:
a) Insulin
b) ADH (vasopressin)
c) Aldosterone
d) Parathyroid hormone
Answer: b) ADH (vasopressin)
- a) Insulin deficiency → diabetes mellitus, not DI.
- b) ADH deficiency or renal resistance — correct; leads to inability to concentrate urine (polyuria, polydipsia).
- c/d) Aldosterone/PTH — unrelated to primary water concentrating defect.
Q16. Which hormone stimulates growth primarily via insulin-like growth factor 1 (IGF-1) production in the liver?
a) Thyroxine (T4)
b) Growth hormone (GH)
c) Prolactin
d) Cortisol
Answer: b) Growth hormone (GH)
- a) T4 — permissive for growth but not main mediator.
- b) GH — correct; GH acts on liver to produce IGF-1 which mediates many growth effects.
- c) Prolactin — lactation; minor growth roles.
- d) Cortisol — catabolic in excess, inhibits growth.
Q17. A patient with low blood Na⁺ concentration and high urine Na⁺ is likely to have excess:
a) ADH
b) Aldosterone
c) ANP (atrial natriuretic peptide)
d) PTH
Answer: c) ANP (atrial natriuretic peptide)
- a) ADH — causes water retention; tends to dilute Na⁺ (hyponatremia) but not cause high urinary Na⁺ excretion.
- b) Aldosterone — promotes Na⁺ reabsorption (would lower urinary Na⁺).
- c) ANP — correct; increases Na⁺ excretion and diuresis → can lower plasma Na⁺ if water balance shifts or cause natriuresis → high urinary Na⁺.
- d) PTH — acts on Ca²⁺/PO₄³⁻.
Q18. Which gland is primarily responsible for circadian rhythm regulation via melatonin secretion?
a) Thyroid gland
b) Pineal gland
c) Pituitary gland
d) Adrenal gland
Answer: b) Pineal gland
- a) Thyroid — metabolic regulation.
- b) Pineal — correct; secretes melatonin in response to darkness, regulates sleep-wake cycles.
- c) Pituitary — master endocrine but not primary melatonin source.
- d) Adrenal — cortisol secretion with diurnal rhythm, but melatonin is pineal.
Q19. Which hormone increases uterine contractions during childbirth and is released in positive feedback loop?
a) Prolactin
b) Oxytocin
c) Progesterone
d) Estrogen
Answer: b) Oxytocin
- a) Prolactin — milk production.
- b) Oxytocin — correct; uterine contractions stimulate more oxytocin release (positive feedback) until delivery.
- c/d) Progesterone/estrogen — modulate uterine conditions but oxytocin mediates contraction surge.
Q20. Which hormone increases intestinal Ca²⁺ absorption by promoting vitamin D activation?
a) Parathyroid hormone (PTH)
b) Calcitonin
c) Aldosterone
d) Insulin
Answer: a) Parathyroid hormone (PTH)
- a) PTH — correct. PTH stimulates renal 1α-hydroxylase to convert 25-OH vitamin D to active 1,25-(OH)₂D (calcitriol) → ↑intestinal Ca²⁺ absorption.
- b) Calcitonin — decreases blood Ca²⁺.
- c/d) Aldosterone/insulin — not primary in vitamin D activation.
Q21. Which hormonal change is most characteristic of type 1 diabetes mellitus?
a) Increased insulin and decreased glucagon
b) Decreased insulin and increased glucagon
c) Increased insulin and increased glucagon
d) Decreased insulin and decreased glucagon
Answer: b) Decreased insulin and increased glucagon
- a/c/d) Incorrect patterns.
- b) Decreased insulin (β-cell destruction) with relative increase in glucagon — correct; lack of insulin and unopposed glucagon promote hyperglycemia and ketoacidosis risk.
Q22. The principal action of thyroid hormones (T3/T4) is to:
a) Decrease basal metabolic rate (BMR)
b) Increase basal metabolic rate and enhance growth and development
c) Inhibit protein synthesis entirely
d) Only regulate calcium homeostasis
Answer: b) Increase basal metabolic rate and enhance growth and development
- a) Decrease BMR — opposite of thyroid action.
- b) Increase BMR & support growth/development — correct. Thyroid hormones increase O₂ consumption, heat production, and potentiate GH effects.
- c/d) Incorrect.
Q23. Which hormone is secreted by pancreatic β-cells?
a) Glucagon
b) Insulin
c) Somatostatin
d) Pancreatic polypeptide
Answer: b) Insulin
- a) Glucagon — secreted by α-cells.
- b) Insulin — correct; β-cells produce insulin, lowering blood glucose.
- c) Somatostatin — δ-cells (inhibits many hormones).
- d) Pancreatic polypeptide — F cells.
Q24. Which hormone is involved in the “fight or flight” response and is released from adrenal medulla?
a) Aldosterone
b) Cortisol
c) Epinephrine (adrenaline)
d) Insulin
Answer: c) Epinephrine (adrenaline)
- a) Aldosterone — mineralocorticoid from cortex.
- b) Cortisol — stress hormone from cortex (slower genomic effects).
- c) Epinephrine — correct; rapid sympathetic catecholamine surge for fight-or-flight (↑HR, bronchodilation, glycogenolysis).
- d) Insulin — anabolic metabolic hormone.
Q25. Which hormone acts as an antagonist to PTH to lower blood Ca²⁺?
a) Thyroxine (T4)
b) Calcitonin
c) Vitamin D (calcitriol)
d) Aldosterone
Answer: b) Calcitonin
- a) T4 — not primary Ca²⁺ regulator.
- b) Calcitonin — correct; secreted by thyroid C cells, inhibits osteoclasts and lowers blood Ca²⁺ (effect modest in adults).
- c) Vitamin D — increases Ca²⁺ absorption (synergistic with PTH), not antagonist.
- d) Aldosterone — Na⁺/K⁺ regulator.
Part 2: MCQs (Q26–Q50) Human Physiology – Chemical Coordination and Integration
Q26. Which of the following glands is both endocrine and exocrine in nature?
a) Liver
b) Pancreas
c) Thyroid
d) Adrenal
✅ Answer: b) Pancreas
- Explanation: The pancreas has endocrine parts (Islets of Langerhans – secreting insulin and glucagon) and exocrine parts (acini – secreting digestive enzymes).
Q27. Which hormone regulates the basal metabolic rate (BMR) of the body?
a) Insulin
b) Thyroxine
c) Cortisol
d) Glucagon
✅ Answer: b) Thyroxine
- Explanation: Thyroxine (T4) and triiodothyronine (T3) secreted by the thyroid gland control BMR, influencing metabolism and energy production.
Q28. The ‘fight or flight’ response is regulated by which hormone?
a) Thyroxine
b) Insulin
c) Adrenaline
d) Cortisol
✅ Answer: c) Adrenaline
- Explanation: Adrenal medulla secretes adrenaline, which increases heart rate, blood pressure, and prepares the body for emergencies.
Q29. Addison’s disease is caused due to hyposecretion of which hormone?
a) Cortisol
b) Aldosterone
c) Both cortisol and aldosterone
d) Insulin
✅ Answer: c) Both cortisol and aldosterone
- Explanation: Addison’s disease is caused by adrenal cortex failure leading to reduced secretion of cortisol and aldosterone, causing weakness, hypotension, and pigmentation.
Q30. Which gland is called the ‘master gland’?
a) Thyroid
b) Pituitary
c) Hypothalamus
d) Pineal
✅ Answer: b) Pituitary
- Explanation: The pituitary regulates the activity of several endocrine glands (thyroid, adrenal, gonads), hence called the master gland.
Q31. Insulin was discovered by
a) Pavlov
b) Banting and Best
c) Fleming
d) Hodgkin
✅ Answer: b) Banting and Best
- Explanation: In 1921, Frederick Banting and Charles Best discovered insulin, which controls blood glucose.
Q32. Which hormone promotes reabsorption of water from kidney tubules?
a) Aldosterone
b) ADH
c) Cortisol
d) Oxytocin
✅ Answer: b) ADH
- Explanation: Antidiuretic hormone (Vasopressin) increases water reabsorption from distal tubules and collecting ducts.
Q33. Which hormone regulates the sleep–wake cycle?
a) Insulin
b) Melatonin
c) Thyroxine
d) Glucagon
✅ Answer: b) Melatonin
- Explanation: Pineal gland secretes melatonin, which regulates circadian rhythm and sleep–wake cycles.
Q34. Which hormone maintains calcium balance by increasing its level in blood?
a) Calcitonin
b) Parathyroid hormone
c) Thyroxine
d) Aldosterone
✅ Answer: b) Parathyroid hormone
- Explanation: Parathyroid hormone increases blood calcium by stimulating bone resorption and reabsorption from kidneys.
Q35. Cushing’s syndrome is caused due to
a) Hyposecretion of cortisol
b) Hypersecretion of cortisol
c) Hyposecretion of aldosterone
d) Hypersecretion of insulin
✅ Answer: b) Hypersecretion of cortisol
- Explanation: Overproduction of cortisol by adrenal cortex causes obesity, hypertension, and moon face (Cushing’s syndrome).
Q36. Gigantism is caused due to
a) Hypersecretion of GH before puberty
b) Hypersecretion of GH after puberty
c) Hyposecretion of GH before puberty
d) Hyposecretion of GH after puberty
✅ Answer: a) Hypersecretion of GH before puberty
- Explanation: Excess growth hormone before closure of epiphyseal plates results in gigantism.
Q37. Which of the following is a glucocorticoid?
a) Aldosterone
b) Cortisol
c) Adrenaline
d) Melatonin
✅ Answer: b) Cortisol
- Explanation: Cortisol is a glucocorticoid from adrenal cortex, regulating metabolism and stress response.
Q38. Hypothyroidism during pregnancy may cause
a) Cretinism in child
b) Goitre
c) Acromegaly
d) Addison’s disease
✅ Answer: a) Cretinism in child
- Explanation: Severe deficiency of maternal thyroid hormones leads to mental retardation and stunted growth in the newborn (cretinism).
Q39. The hormone prolactin is secreted by
a) Posterior pituitary
b) Anterior pituitary
c) Hypothalamus
d) Ovary
✅ Answer: b) Anterior pituitary
- Explanation: Prolactin stimulates milk production in mammary glands and is secreted by anterior pituitary.
Q40. The target organ of TSH (Thyroid Stimulating Hormone) is
a) Adrenal
b) Thyroid
c) Pancreas
d) Kidney
✅ Answer: b) Thyroid
- Explanation: TSH from anterior pituitary stimulates the thyroid gland to secrete thyroxine and triiodothyronine.
Q41. Which hormone is responsible for the “let down reflex” in lactating mothers?
a) Prolactin
b) Oxytocin
c) FSH
d) LH
✅ Answer: b) Oxytocin
- Explanation: Oxytocin causes contraction of mammary gland alveoli and helps in milk ejection during breastfeeding.
Q42. The ‘Islets of Langerhans’ are associated with which gland?
a) Thyroid
b) Adrenal
c) Pancreas
d) Pituitary
✅ Answer: c) Pancreas
- Explanation: Endocrine portion of pancreas has islets of Langerhans secreting insulin, glucagon, and somatostatin.
Q43. The main hormone responsible for ovulation is
a) FSH
b) LH
c) Estrogen
d) Progesterone
✅ Answer: b) LH
- Explanation: A sudden surge of Luteinizing Hormone (LH) from anterior pituitary causes ovulation.
Q44. Which of the following is NOT secreted by adrenal cortex?
a) Cortisol
b) Aldosterone
c) Androgens
d) Adrenaline
✅ Answer: d) Adrenaline
- Explanation: Adrenal cortex secretes cortisol, aldosterone, and androgens, while adrenaline is secreted by adrenal medulla.
Q45. The ‘stress hormone’ cortisol belongs to which group?
a) Mineralocorticoids
b) Glucocorticoids
c) Catecholamines
d) Peptide hormones
✅ Answer: b) Glucocorticoids
- Explanation: Cortisol, a glucocorticoid, regulates stress response, metabolism, and immunity.
Q46. Which hormone decreases blood calcium level?
a) PTH
b) Calcitonin
c) Thyroxine
d) Cortisol
✅ Answer: b) Calcitonin
- Explanation: Calcitonin, secreted by thyroid gland, lowers blood calcium by inhibiting bone resorption.
Q47. Goitre is caused due to deficiency of
a) Iron
b) Iodine
c) Calcium
d) Sodium
✅ Answer: b) Iodine
- Explanation: Iodine deficiency reduces thyroxine synthesis, leading to enlargement of thyroid gland (goitre).
Q48. Which hormone is called the ‘hormone of emergency’?
a) Thyroxine
b) Adrenaline
c) Cortisol
d) Glucagon
✅ Answer: b) Adrenaline
- Explanation: Adrenaline secreted during stress increases heart rate and blood supply, preparing body for emergencies.
Q49. Which gland is located on the dorsal side of the forebrain?
a) Thyroid
b) Pituitary
c) Pineal
d) Adrenal
✅ Answer: c) Pineal
- Explanation: Pineal gland is situated on the dorsal side of the forebrain and secretes melatonin.
Q50. Hyposecretion of ADH causes which disorder?
a) Diabetes mellitus
b) Diabetes insipidus
c) Acromegaly
d) Goitre
✅ Answer: b) Diabetes insipidus
- Explanation: Deficiency of ADH results in excessive urine output and dehydration, a condition called diabetes insipidus.
Part 3: MCQs (Q51–Q75) Human Physiology – Chemical Coordination and Integration
Q51. Which hormone regulates basal metabolic rate (BMR)?
a) Cortisol
b) Thyroxine
c) Insulin
d) Growth hormone
✅ Answer: b) Thyroxine
- Explanation: Thyroxine (T4) and Triiodothyronine (T3) from the thyroid gland regulate metabolism, oxygen consumption, and BMR.
Q52. Which hormone is called the “stress hormone”?
a) Adrenaline
b) Cortisol
c) Aldosterone
d) Glucagon
✅ Answer: b) Cortisol
- Explanation: Cortisol (a glucocorticoid from adrenal cortex) is released during stress and regulates glucose metabolism, blood pressure, and immune response.
Q53. Mineralocorticoids are secreted by:
a) Adrenal medulla
b) Adrenal cortex (zona glomerulosa)
c) Thyroid gland
d) Pituitary gland
✅ Answer: b) Adrenal cortex (zona glomerulosa)
- Explanation: Mineralocorticoids like aldosterone regulate sodium and potassium balance, controlling blood pressure.
Q54. Which hormone increases blood calcium levels?
a) Calcitonin
b) Parathyroid hormone
c) Thyroxine
d) Insulin
✅ Answer: b) Parathyroid hormone
- Explanation: PTH stimulates bone resorption, increases calcium reabsorption in kidneys, and activates Vitamin D, thus raising blood calcium.
Q55. Which pancreatic hormone lowers blood sugar?
a) Glucagon
b) Insulin
c) Somatostatin
d) Adrenaline
✅ Answer: b) Insulin
- Explanation: Insulin facilitates glucose uptake into cells and glycogen formation, lowering blood glucose.
Q56. What is the primary function of melatonin?
a) Stimulates metabolism
b) Controls circadian rhythm
c) Increases blood glucose
d) Increases calcium absorption
✅ Answer: b) Controls circadian rhythm
- Explanation: Melatonin, secreted by the pineal gland, regulates biological clock, sleep–wake cycle, and seasonal reproductive activities.
Q57. Which hormone is secreted by the kidney?
a) Erythropoietin
b) Aldosterone
c) Calcitonin
d) Prolactin
✅ Answer: a) Erythropoietin
- Explanation: Kidneys secrete erythropoietin, which stimulates red blood cell production in the bone marrow.
Q58. Which hormone promotes milk secretion after childbirth?
a) Oxytocin
b) Prolactin
c) Progesterone
d) LH
✅ Answer: b) Prolactin
- Explanation: Prolactin from anterior pituitary stimulates mammary glands to produce milk after childbirth.
Q59. Addison’s disease is caused by:
a) Hyposecretion of cortisol and aldosterone
b) Hypersecretion of cortisol
c) Hypersecretion of insulin
d) Hyposecretion of thyroxine
✅ Answer: a) Hyposecretion of cortisol and aldosterone
- Explanation: Addison’s disease results in weakness, weight loss, and low blood pressure due to adrenal cortex insufficiency.
Q60. Which hormone is associated with “fight or flight” response?
a) Insulin
b) Thyroxine
c) Adrenaline
d) Cortisol
✅ Answer: c) Adrenaline
- Explanation: Adrenaline (epinephrine) increases heart rate, blood glucose, and respiration rate during emergencies.
Q61. Which hormone promotes reabsorption of sodium in kidneys?
a) Cortisol
b) Aldosterone
c) Vasopressin
d) Calcitonin
✅ Answer: b) Aldosterone
- Explanation: Aldosterone, a mineralocorticoid, enhances sodium reabsorption and potassium excretion in renal tubules.
Q62. Hypersecretion of growth hormone in adults causes:
a) Gigantism
b) Acromegaly
c) Dwarfism
d) Cretinism
✅ Answer: b) Acromegaly
- Explanation: Excess GH in adults enlarges extremities (hands, feet, face), while in children it causes gigantism.
Q63. Which hormone increases uterine contractions during childbirth?
a) Prolactin
b) Oxytocin
c) Estrogen
d) Relaxin
✅ Answer: b) Oxytocin
- Explanation: Oxytocin from the posterior pituitary enhances uterine contractions during labor and aids milk ejection.
Q64. Graves’ disease is caused by:
a) Hypothyroidism
b) Hyperthyroidism
c) Hypoparathyroidism
d) Hyperparathyroidism
✅ Answer: b) Hyperthyroidism
- Explanation: Graves’ disease involves excess thyroid hormone secretion, leading to weight loss, high BMR, and exophthalmia.
Q65. Which hormone inhibits secretion of other hormones in pancreas?
a) Insulin
b) Glucagon
c) Somatostatin
d) Aldosterone
✅ Answer: c) Somatostatin
- Explanation: Somatostatin suppresses insulin and glucagon release, maintaining glucose homeostasis.
Q66. The hormone secreted during “emergency situations” is:
a) Noradrenaline and adrenaline
b) Aldosterone
c) Thyroxine
d) Insulin
✅ Answer: a) Noradrenaline and adrenaline
- Explanation: Both adrenaline and noradrenaline are secreted from adrenal medulla during stress or emergencies.
Q67. Which gland is also known as the “master gland”?
a) Thyroid
b) Adrenal
c) Pituitary
d) Pancreas
✅ Answer: c) Pituitary
- Explanation: Pituitary gland regulates other endocrine glands through tropic hormones.
Q68. Deficiency of insulin causes:
a) Diabetes mellitus
b) Diabetes insipidus
c) Goitre
d) Acromegaly
✅ Answer: a) Diabetes mellitus
- Explanation: Insulin deficiency or resistance leads to hyperglycemia and glucosuria (diabetes mellitus).
Q69. The hormone responsible for water reabsorption in kidneys is:
a) Aldosterone
b) ADH (Vasopressin)
c) Oxytocin
d) PTH
✅ Answer: b) ADH (Vasopressin)
- Explanation: ADH from posterior pituitary promotes water reabsorption in kidney collecting ducts.
Q70. Which hormone is derived from cholesterol?
a) Insulin
b) Glucagon
c) Cortisol
d) Thyroxine
✅ Answer: c) Cortisol
- Explanation: Steroid hormones (cortisol, aldosterone, sex hormones) are derived from cholesterol.
Q71. Which hormone stimulates glycogen breakdown?
a) Insulin
b) Glucagon
c) Aldosterone
d) Thyroxine
✅ Answer: b) Glucagon
- Explanation: Glucagon promotes glycogenolysis in liver, increasing blood glucose levels.
Q72. Cretinism is caused due to:
a) Hyposecretion of GH in childhood
b) Hyposecretion of thyroid hormones in childhood
c) Hyposecretion of insulin
d) Hypersecretion of cortisol
✅ Answer: b) Hyposecretion of thyroid hormones in childhood
- Explanation: Deficiency of thyroid hormones in childhood causes mental retardation and stunted growth (cretinism).
Q73. Which hormone regulates female secondary sexual characteristics?
a) Testosterone
b) Estrogen
c) Progesterone
d) LH
✅ Answer: b) Estrogen
- Explanation: Estrogen secreted by ovarian follicles regulates development of female reproductive system and secondary sexual traits.
Q74. Hyperparathyroidism leads to:
a) Low blood calcium
b) High blood calcium and bone resorption
c) Goitre
d) Diabetes insipidus
✅ Answer: b) High blood calcium and bone resorption
- Explanation: Excess PTH causes hypercalcemia, kidney stones, and osteoporosis.
Q75. Which of the following is a peptide hormone?
a) Cortisol
b) Aldosterone
c) Insulin
d) Testosterone
✅ Answer: c) Insulin
- Explanation: Insulin is a protein/peptide hormone, while cortisol, aldosterone, and testosterone are steroid hormones.
Part 4: Human Physiology – Chemical Coordination and Integration (Q76–Q100)
Q76. Which hormone increases basal metabolic rate (BMR)?
a) Insulin
b) Thyroxine
c) Cortisol
d) Aldosterone
Answer: b) Thyroxine
- Explanation: Thyroxine (T4) and triiodothyronine (T3) secreted by the thyroid gland increase metabolism and oxygen consumption, thus raising BMR.
Q77. The adrenal medulla is functionally associated with which response?
a) Rest and digest
b) Fight or flight
c) Long-term adaptation
d) Water balance
Answer: b) Fight or flight
- Explanation: Adrenal medulla secretes adrenaline and noradrenaline, which prepare the body for emergencies, increasing heart rate, blood pressure, and respiration.
Q78. Which hormone regulates circadian rhythm and sleep-wake cycle?
a) Melatonin
b) Oxytocin
c) Calcitonin
d) Estrogen
Answer: a) Melatonin
- Explanation: The pineal gland secretes melatonin, which controls circadian rhythm and induces sleep.
Q79. Deficiency of ADH (Vasopressin) causes which disorder?
a) Diabetes mellitus
b) Diabetes insipidus
c) Addison’s disease
d) Myxedema
Answer: b) Diabetes insipidus
- Explanation: Lack of ADH reduces water reabsorption in kidneys, causing excessive urination and thirst.
Q80. Which hormone stimulates secretion of milk after childbirth?
a) Estrogen
b) Progesterone
c) Prolactin
d) Oxytocin
Answer: c) Prolactin
- Explanation: Prolactin secreted by the anterior pituitary promotes lactation by stimulating mammary glands.
Q81. Which pancreatic cells secrete insulin?
a) Alpha cells
b) Beta cells
c) Delta cells
d) F cells
Answer: b) Beta cells
- Explanation: Beta cells of the islets of Langerhans secrete insulin, which decreases blood glucose levels.
Q82. Hypersecretion of growth hormone in adults causes:
a) Dwarfism
b) Acromegaly
c) Gigantism
d) Cretinism
Answer: b) Acromegaly
- Explanation: In adults, excess GH causes acromegaly, leading to abnormal enlargement of jaw, hands, and feet.
Q83. Which hormone regulates sodium reabsorption in kidneys?
a) Cortisol
b) Aldosterone
c) Adrenaline
d) Insulin
Answer: b) Aldosterone
- Explanation: Aldosterone from the adrenal cortex regulates sodium and potassium balance, increasing Na⁺ reabsorption.
Q84. Which is not an effect of adrenaline?
a) Increased heart rate
b) Pupil dilation
c) Decreased blood pressure
d) Increased glucose release
Answer: c) Decreased blood pressure
- Explanation: Adrenaline raises blood pressure, heart rate, and glucose levels to prepare for stress.
Q85. Which hormone helps in parturition (childbirth)?
a) Prolactin
b) Oxytocin
c) Relaxin
d) Estrogen
Answer: b) Oxytocin
- Explanation: Oxytocin secreted by posterior pituitary stimulates uterine contractions during labor.
Q86. Hypothyroidism in children results in:
a) Gigantism
b) Cretinism
c) Myxedema
d) Goiter
Answer: b) Cretinism
- Explanation: Deficiency of thyroid hormones in children causes cretinism, characterized by mental retardation and stunted growth.
Q87. Which hormone is secreted by the kidney?
a) Erythropoietin
b) Calcitonin
c) Glucagon
d) Vasopressin
Answer: a) Erythropoietin
- Explanation: Erythropoietin is secreted by kidneys to stimulate red blood cell production in bone marrow.
Q88. Which hormone lowers blood calcium levels?
a) Parathyroid hormone
b) Calcitonin
c) Thyroxine
d) Cortisol
Answer: b) Calcitonin
- Explanation: Calcitonin from thyroid gland lowers blood calcium by promoting deposition in bones.
Q89. Addison’s disease is caused due to deficiency of:
a) Cortisol
b) Insulin
c) Thyroxine
d) Growth hormone
Answer: a) Cortisol
- Explanation: Hyposecretion of adrenal cortex hormones (especially cortisol and aldosterone) leads to Addison’s disease.
Q90. Which gland acts as both endocrine and exocrine?
a) Thyroid
b) Pituitary
c) Pancreas
d) Adrenal
Answer: c) Pancreas
- Explanation: Pancreas functions as endocrine (insulin, glucagon) and exocrine (digestive enzymes).
Q91. Which hormone stimulates spermatogenesis in males?
a) LH
b) FSH
c) Prolactin
d) Oxytocin
Answer: b) FSH
- Explanation: Follicle stimulating hormone stimulates spermatogenesis in testes by acting on Sertoli cells.
Q92. Which hormone is secreted during long-term stress?
a) Adrenaline
b) Cortisol
c) Insulin
d) Thyroxine
Answer: b) Cortisol
- Explanation: Cortisol is secreted by adrenal cortex and regulates metabolism, immune suppression, and adaptation to long-term stress.
Q93. Hyperparathyroidism leads to:
a) Hypocalcemia
b) Hypercalcemia
c) Low bone density
d) Both b and c
Answer: d) Both b and c
- Explanation: Excess PTH increases calcium levels in blood and decreases bone mineral density.
Q94. Which hormone stimulates ovulation in females?
a) FSH
b) LH
c) Estrogen
d) Progesterone
Answer: b) LH
- Explanation: A sudden surge of LH induces ovulation and formation of corpus luteum.
Q95. Which part of adrenal gland secretes glucocorticoids?
a) Medulla
b) Cortex – Zona fasciculata
c) Cortex – Zona glomerulosa
d) Cortex – Zona reticularis
Answer: b) Cortex – Zona fasciculata
- Explanation: Glucocorticoids (mainly cortisol) are secreted by zona fasciculata of adrenal cortex.
Q96. Which hormone is also called “stress hormone”?
a) Adrenaline
b) Noradrenaline
c) Cortisol
d) Thyroxine
Answer: c) Cortisol
- Explanation: Cortisol is the stress hormone that helps the body cope with prolonged stress.
Q97. Hypoglycemia is caused by:
a) Excess insulin
b) Deficiency of insulin
c) Excess glucagon
d) Deficiency of cortisol
Answer: a) Excess insulin
- Explanation: Excess insulin lowers blood sugar excessively, leading to hypoglycemia.
Q98. Which gland is often called the “master gland”?
a) Thyroid
b) Pituitary
c) Hypothalamus
d) Adrenal
Answer: b) Pituitary
- Explanation: Pituitary controls secretion of many other endocrine glands, hence called master gland.
Q99. Goiter is caused by deficiency of:
a) Iodine
b) Iron
c) Calcium
d) Sodium
Answer: a) Iodine
- Explanation: Iodine deficiency leads to decreased thyroxine synthesis and enlargement of thyroid gland (goiter).
Q100. Which hormone promotes glycogenolysis in liver?
a) Insulin
b) Glucagon
c) Calcitonin
d) Aldosterone
Answer: b) Glucagon
- Explanation: Glucagon secreted by alpha cells of pancreas increases blood sugar by promoting glycogen breakdown.
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