Question

how much do you know about your heart? find out by taking this quiz!
quiz: heart & circulatory system
q.3 the beating sound your heart makes comes from:
a) blood going in the wrong direction
b) valves closing
c) the heart skipping beats
d) your ears playing tricks on you

Explanation:

The heart has valves (such as the mitral, tricuspid, aortic, and pulmonary valves). When these valves close, they create the characteristic "lub - dub" sound of the heartbeat. Blood going in the wrong direction (like in cases of valve regurgitation) can cause abnormal heart sounds (murmurs) but not the normal beating sound. The heart skipping beats (arrhythmias) also cause abnormal heart rhythms and sounds different from the normal beating sound. And it's not a trick of the ears as the heart sound can be objectively heard with a stethoscope.

Answer:

B. Valves closing