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: Oxygen consumption increases most during
A) Fasting
B) Exercise
C) Sleep
D) Rest
✅ Correct Answer: B
Explanation: Physical activity elevates metabolic demand, increasing oxygen utilization.
Q: The structure that acts as the pacemaker of the heart
A) SA node
B) Purkinje fibers
C) AV node
D) Bundle of His
✅ Correct Answer: A
Explanation: The SA node initiates impulses that set the rhythm of the heartbeat.
Q: Baroreceptors primarily detect
A) Blood pressure changes
B) Oxygen saturation
C) Blood viscosity
D) Blood glucose
✅ Correct Answer: A
Explanation: Baroreceptors in the aorta and carotid sinus respond to stretch from pressure.
Q: Insulin secretion is stimulated by
A) Hyperglycemia
B) Fasting
C) Glucagon
D) Hypoglycemia
✅ Correct Answer: A
Explanation: High blood glucose levels stimulate pancreatic beta cells to release insulin.
Q: The primary action of aldosterone
A) Water excretion
B) Glucose metabolism
C) Protein synthesis
D) Sodium retention
✅ Correct Answer: D
Explanation: Aldosterone promotes sodium reabsorption in the distal nephron, increasing fluid retention.