MBBS Physiology 3

Question 1

What is the normal central venous pressure (CVP) range?

Accepted Answer

2–6 mmHg

Answer

Normal CVP is 2–6 mmHg, reflecting right atrial filling pressure and serving as an estimate of preload.

Question 2

Which neurotransmitter is released at the neuromuscular junction?

Accepted Answer

Acetylcholine

Answer

Acetylcholine is released from motor neurons at the neuromuscular junction and binds nicotinic receptors on skeletal muscle.

Question 3

The Hering-Breuer reflex is mediated by which receptors?

Accepted Answer

Pulmonary stretch receptors (slowly adapting)

Answer

The Hering-Breuer reflex is triggered by slowly adapting pulmonary stretch receptors that signal the brain to stop inspiration when lungs are over-inflated.

Question 4

Which ion is primarily responsible for the pacemaker potential (funny current) in the SA node?

Accepted Answer

Na+

Answer

The funny current (If) in SA node pacemaker cells is mainly carried by Na+ influx through HCN channels during hyperpolarization, initiating spontaneous depolarization.

Question 5

Which vitamin deficiency leads to impaired collagen synthesis and is associated with scurvy?

Accepted Answer

Vitamin C

Answer

Vitamin C (ascorbic acid) is required for hydroxylation of proline and lysine residues in collagen, and its deficiency causes scurvy with poor wound healing and bleeding gums.

MBBS - Bachelor of Medicine and Bachelor of Surgery Practice Test

MBBS - Bachelor of Medicine and Bachelor of Surgery Practice Test

MBBS Physiology 3