Question

Murmurs are generally heard in disorders affecting the following: 

• A. SA nodes
• B. Pulmonary vein
• C. AV nodes
• D. Heart valves

Answer 1

The Correct Option is D

The correct option is (D): Heart valves.

Answer 2

The question asks which structure, when diseased, typically produces a murmur, an abnormal sound heard on listening to the heart. Let's go through each option.

1. SA nodes: The sinoatrial node sets the pace of the heartbeat by generating electrical impulses. Problems here cause abnormal heart rates or rhythms, not the turbulent blood-flow sounds that define a murmur.
2. Pulmonary vein: These veins carry oxygen-rich blood from the lungs back to the heart. Disease here is more linked to conditions like pulmonary hypertension, and does not typically create the classic murmur sound.
3. AV nodes: The atrioventricular node relays electrical signals from the atria to the ventricles. Disorders here cause conduction blocks and rhythm problems, again a matter of electrical timing rather than blood-flow sound.
4. Heart valves: A murmur is the sound of blood flowing turbulently rather than smoothly, which happens when a valve is narrowed (stenosis) and blood is forced through a tight opening, or when a valve leaks (regurgitation) and blood flows backward. Both situations disturb the normal smooth flow and create the whooshing or blowing sound a clinician hears through a stethoscope.

Since a murmur is fundamentally a sign of disturbed blood flow, and it is the heart valves that control the direction and smoothness of that flow, valve disease is the structure most directly tied to murmurs.

So the correct answer is Heart valves.