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: Contraction of skeletal muscle is initiated by
A) Serotonin
B) Acetylcholine
C) Dopamine
D) GABA
✅ Correct Answer: B
Explanation: Acetylcholine released at neuromuscular junction binds to receptors, triggering muscle contraction.
Q: The primary pacemaker of the heart
A) Bundle of His
B) SA node
C) Purkinje fibers
D) AV node
✅ Correct Answer: B
Explanation: SA node generates impulses that initiate the heartbeat rhythm.
Q: Hemoglobin's oxygen affinity increases in
A) Low pH
B) Low temperature
C) High CO₂
D) High 2,3-BPG
✅ Correct Answer: B
Explanation: Low temperature stabilizes the oxygen-bound form of hemoglobin.
Q: Gas exchange in the lungs takes place at
A) Trachea
B) Bronchioles
C) Alveoli
D) Bronchi
✅ Correct Answer: C
Explanation: Alveoli are the thin-walled structures where diffusion of gases occurs.
Q: The resting membrane potential of a typical neuron is about
A) −70 mV
B) 0 mV
C) +30 mV
D) −90 mV
✅ Correct Answer: A
Explanation: A typical neuron maintains a resting potential of −70 mV due to ion distribution.