Q.1 Which hormone is primarily responsible for regulating blood calcium levels?
Calcitonin
Insulin
Glucagon
Aldosterone
Explanation - Calcitonin, secreted by the thyroid gland, lowers blood calcium levels by inhibiting osteoclast activity and promoting calcium deposition in bones.
Correct answer is: Calcitonin
Q.2 The release of cortisol from the adrenal cortex is mainly regulated by which hormone?
ACTH
TSH
LH
GH
Explanation - Adrenocorticotropic hormone (ACTH) from the anterior pituitary stimulates the adrenal cortex to release cortisol, a key stress hormone.
Correct answer is: ACTH
Q.3 Which hormone lowers blood glucose levels?
Glucagon
Insulin
Cortisol
Adrenaline
Explanation - Insulin, produced by pancreatic β-cells, promotes glucose uptake by cells and glycogen formation, thereby lowering blood glucose levels.
Correct answer is: Insulin
Q.4 Parathyroid hormone (PTH) primarily acts on which organ to increase blood calcium?
Liver
Kidney
Pancreas
Heart
Explanation - PTH increases blood calcium by stimulating calcium reabsorption in the kidneys, activating vitamin D, and mobilizing calcium from bones.
Correct answer is: Kidney
Q.5 Which hormone is secreted in response to low blood glucose levels?
Insulin
Glucagon
Aldosterone
TSH
Explanation - Glucagon, produced by pancreatic α-cells, raises blood glucose by promoting glycogen breakdown in the liver.
Correct answer is: Glucagon
Q.6 Which of the following hormones is secreted by the posterior pituitary?
Oxytocin
Prolactin
TSH
ACTH
Explanation - Oxytocin is stored and released by the posterior pituitary and plays roles in uterine contraction and milk ejection.
Correct answer is: Oxytocin
Q.7 Which hormone increases sodium reabsorption in the kidneys?
Aldosterone
Cortisol
Insulin
GH
Explanation - Aldosterone, secreted by the adrenal cortex, increases sodium reabsorption and potassium excretion in the distal tubules of the kidney.
Correct answer is: Aldosterone
Q.8 Thyroid hormones primarily affect which process?
Metabolism
Blood clotting
Glucose excretion
Red blood cell formation
Explanation - Thyroid hormones T3 and T4 increase basal metabolic rate by stimulating cellular oxygen consumption and energy production.
Correct answer is: Metabolism
Q.9 Which hormone is responsible for the 'fight or flight' response?
Adrenaline
Insulin
Glucagon
PTH
Explanation - Adrenaline (epinephrine) is released from the adrenal medulla in response to stress, increasing heart rate, blood flow, and energy availability.
Correct answer is: Adrenaline
Q.10 Which hormone is produced by the pancreas to raise blood glucose levels?
Glucagon
Insulin
Somatostatin
Ghrelin
Explanation - Glucagon, secreted by α-cells of the pancreas, promotes glycogenolysis and gluconeogenesis to raise blood glucose.
Correct answer is: Glucagon
Q.11 Which hormone stimulates milk production in lactating women?
Prolactin
Oxytocin
TSH
GH
Explanation - Prolactin, secreted by the anterior pituitary, promotes milk synthesis in mammary glands.
Correct answer is: Prolactin
Q.12 Which hormone directly controls the menstrual cycle?
Estrogen
Testosterone
Progesterone
Both A and C
Explanation - Estrogen and progesterone, secreted by the ovaries, regulate the menstrual cycle through effects on the endometrium and feedback on the pituitary.
Correct answer is: Both A and C
Q.13 Which hormone is involved in regulating circadian rhythm?
Melatonin
Serotonin
Cortisol
Insulin
Explanation - Melatonin, produced by the pineal gland, regulates sleep-wake cycles in response to light-dark signals.
Correct answer is: Melatonin
Q.14 Which of the following hormones is secreted by the adrenal medulla?
Cortisol
Aldosterone
Adrenaline
TSH
Explanation - The adrenal medulla secretes catecholamines, mainly adrenaline (epinephrine) and noradrenaline, which are critical for stress response.
Correct answer is: Adrenaline
Q.15 Which hormone is responsible for lowering blood potassium levels?
Aldosterone
PTH
Cortisol
Insulin
Explanation - Aldosterone promotes potassium excretion in the kidneys while increasing sodium reabsorption, thereby lowering blood potassium.
Correct answer is: Aldosterone
Q.16 Which hormone stimulates the adrenal cortex to release cortisol?
ACTH
TSH
FSH
LH
Explanation - ACTH from the anterior pituitary binds to receptors on adrenal cortical cells, triggering cortisol synthesis and release.
Correct answer is: ACTH
Q.17 Which hormone promotes gluconeogenesis in the liver?
Glucagon
Insulin
Aldosterone
GH
Explanation - Glucagon stimulates gluconeogenesis and glycogenolysis in the liver to increase blood glucose levels during fasting.
Correct answer is: Glucagon
Q.18 Which of the following hormones has a major role in water retention?
ADH
Oxytocin
TSH
Prolactin
Explanation - Antidiuretic hormone (ADH), secreted by the posterior pituitary, increases water reabsorption in the kidneys to maintain body water balance.
Correct answer is: ADH
Q.19 Which hormone regulates sodium and potassium balance in the body?
Aldosterone
Insulin
Cortisol
PTH
Explanation - Aldosterone regulates electrolyte balance by increasing sodium reabsorption and potassium excretion in the kidneys.
Correct answer is: Aldosterone
Q.20 Which hormone increases heart rate and blood pressure during stress?
Adrenaline
Insulin
Cortisol
Glucagon
Explanation - Adrenaline enhances cardiovascular output during stress by increasing heart rate and constricting blood vessels.
Correct answer is: Adrenaline
Q.21 Which hormone is critical for growth and development in children?
Growth Hormone
Insulin
Cortisol
Glucagon
Explanation - GH, secreted by the anterior pituitary, stimulates protein synthesis, bone growth, and overall body growth during childhood and adolescence.
Correct answer is: Growth Hormone
Q.22 Which hormone is involved in stress adaptation and immune modulation?
Cortisol
Insulin
Glucagon
TSH
Explanation - Cortisol helps the body respond to stress by mobilizing energy reserves and modulating inflammation and immunity.
Correct answer is: Cortisol
Q.23 Which hormone regulates the release of thyroid hormones from the thyroid gland?
TSH
ACTH
LH
GH
Explanation - Thyroid-stimulating hormone (TSH) from the anterior pituitary binds to thyroid follicular cells, stimulating T3 and T4 synthesis.
Correct answer is: TSH
Q.24 Which hormone is secreted by the pancreas to inhibit both insulin and glucagon secretion?
Somatostatin
Ghrelin
PTH
ADH
Explanation - Somatostatin, produced by pancreatic δ-cells, inhibits the secretion of insulin and glucagon, helping regulate blood glucose levels.
Correct answer is: Somatostatin
Q.25 Which hormone is primarily responsible for uterine contractions during labor?
Oxytocin
Prolactin
Estrogen
Progesterone
Explanation - Oxytocin stimulates smooth muscle contraction in the uterus, facilitating childbirth.
Correct answer is: Oxytocin