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: Atrial natriuretic peptide causes
A) Sodium reabsorption
B) Sodium excretion
C) Vasoconstriction
D) Increased ADH secretion
✅ Correct Answer: B
Explanation: ANP promotes natriuresis to reduce blood volume and pressure.
Q: Primary muscle used during normal quiet breathing
A) Internal intercostals
B) Sternocleidomastoid
C) External intercostals
D) Diaphragm
✅ Correct Answer: D
Explanation: The diaphragm contracts and flattens during inspiration at rest.
Q: The region of the brain that controls body temperature
A) Pons
B) Medulla
C) Cerebellum
D) Hypothalamus
✅ Correct Answer: D
Explanation: The hypothalamus regulates body temperature via autonomic responses.
Q: A decrease in blood pH will cause hemoglobin to
A) Increase oxygen binding
B) Form carboxyhemoglobin
C) Release more oxygen
D) Denature
✅ Correct Answer: C
Explanation: Lower pH (Bohr effect) shifts the curve right, enhancing oxygen delivery.
Q: The fastest phase of depolarization in cardiac muscle
A) Phase 4
B) Phase 2
C) Phase 0
D) Phase 1
✅ Correct Answer: C
Explanation: Phase 0 represents rapid Na⁺ influx, causing steep depolarization.