Physiology MCQs
Physiology MCQs help medical and dental students develop a thorough understanding of the body's functional mechanisms. These multiple-choice questions focus on various systems such as cardiovascular, respiratory, renal, digestive, endocrine, and neurophysiology. Practicing these MCQs enhances knowledge retention and exam performance in tests like MDCAT, NTS, USMLE, and FCPS. Whether you're preparing for academic exams or professional licensure, these quizzes provide a solid framework for mastering the dynamic processes of the human body.
Q: The liver detoxifies ammonia by converting it into
A) Creatinine
B) Urea
C) Bile
D) Glucose
✅ Correct Answer: B
Explanation: Ammonia is toxic and must be converted to urea for excretion.
Q: The stretch reflex is mediated by receptors in the
A) Pacinian corpuscle
B) Muscle spindle
C) Meissner’s corpuscle
D) Golgi tendon organ
✅ Correct Answer: B
Explanation: Muscle spindles detect stretch and trigger contraction reflexes.
Q: The largest volume of air that can be exhaled after maximum inhalation is called
A) Tidal volume
B) Vital capacity
C) Inspiratory reserve
D) Residual volume
✅ Correct Answer: B
Explanation: Vital capacity represents the maximum usable lung volume.
Q: Atrial natriuretic peptide reduces blood volume by promoting
A) Protein synthesis
B) Glucose uptake
C) Calcium retention
D) Sodium excretion
✅ Correct Answer: D
Explanation: ANP increases renal sodium loss, reducing water retention and lowering blood volume.
Q: Bile secretion is primarily stimulated by the hormone
A) Oxytocin
B) Cortisol
C) Insulin
D) Cholecystokinin
✅ Correct Answer: D
Explanation: Cholecystokinin stimulates the gallbladder to release bile into the duodenum.
Q: Thermoregulation is coordinated by the
A) Hypothalamus
B) Cerebellum
C) Thalamus
D) Medulla
✅ Correct Answer: A
Explanation: The hypothalamus maintains core temperature by initiating heat loss or production responses.
Q: Synaptic transmission between neurons occurs through
A) Electrical sparks
B) Capillaries
C) Hormones
D) Neurotransmitters
✅ Correct Answer: D
Explanation: Neurotransmitters are released from the presynaptic neuron and bind to receptors on the postsynaptic cell.
Q: The Bohr effect describes the decreased affinity of hemoglobin for oxygen at
A) Higher pH
B) Low CO₂
C) Low temperature
D) Lower pH
✅ Correct Answer: D
Explanation: Acidic conditions favor oxygen release from hemoglobin.
Q: Pancreatic beta cells secrete insulin in response to
A) Low oxygen levels
B) High calcium levels
C) Protein deficiency
D) Increased blood glucose
✅ Correct Answer: D
Explanation: Elevated glucose stimulates insulin release to lower blood sugar.
Q: The primary electrolyte in extracellular fluid is
A) Calcium
B) Sodium
C) Magnesium
D) Potassium
✅ Correct Answer: B
Explanation: Sodium is the dominant ion in the extracellular compartment, influencing osmotic balance.