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: Parathyroid hormone increases blood calcium levels by
A) Inhibiting bone resorption
B) Enhancing calcium excretion
C) Blocking vitamin D synthesis
D) Stimulating bone resorption
✅ Correct Answer: D
Explanation: PTH increases calcium levels by promoting bone breakdown and calcium release.
Q: Cardiac output is the product of
A) Stroke volume and heart rate
B) Oxygen saturation and heart rate
C) Blood pressure and volume
D) Venous return and resistance
✅ Correct Answer: A
Explanation: Cardiac output equals stroke volume times heart rate.
Q: The primary function of the loop of Henle
A) Water reabsorption
B) Bicarbonate secretion
C) Glucose reabsorption
D) Urea secretion
✅ Correct Answer: A
Explanation: The descending limb of the loop reabsorbs water, concentrating the filtrate.
Q: An action potential is propagated due to
A) Active transport
B) Chemical binding
C) Passive diffusion
D) Ion channel activation
✅ Correct Answer: D
Explanation: Voltage-gated ion channels open and close to propagate the electrical impulse.
Q: The main site of nutrient absorption in the GI tract
A) Stomach
B) Duodenum
C) Small intestine
D) Large intestine
✅ Correct Answer: C
Explanation: The small intestine, particularly jejunum and ileum, is the major site for nutrient absorption.