Physiology MCQs
Physiology MCQs help medical and dental students master body functions across cardiovascular, respiratory, renal, digestive, endocrine, and neurophysiology systems. Ideal for MDCAT, NTS, USMLE, and FCPS, these quizzes boost retention and exam success.
Q: The ion mainly responsible for repolarization in neurons
A) Sodium
B) Potassium
C) Calcium
D) Chloride
✅ Correct Answer: B
Explanation: Outward movement of K⁺ restores resting membrane potential after depolarization.
Q: Gastric acid secretion is stimulated by
A) Glucagon
B) Secretin
C) Gastrin
D) Cholecystokinin
✅ Correct Answer: C
Explanation: Gastrin stimulates parietal cells to release HCl in the stomach.
Q: The function of bile salts
A) Enzyme activation
B) Emulsification of fats
C) Protein denaturation
D) Carbohydrate digestion
✅ Correct Answer: B
Explanation: Bile salts break down large fat droplets into smaller micelles for digestion.
Q: The phase of the cardiac cycle when ventricles contract
A) Atrial systole
B) Ventricular systole
C) Diastasis
D) Isovolumetric relaxation
✅ Correct Answer: B
Explanation: During ventricular systole, the ventricles contract and eject blood.
Q: The oxygen-hemoglobin dissociation curve shifts right due to
A) Increased 2,3-BPG
B) Decreased temperature
C) Alkalosis
D) Low CO₂
✅ Correct Answer: A
Explanation: 2,3-BPG decreases hemoglobin’s affinity for oxygen, enhancing release.