Question

how much do you know about your heart? find out by taking this quiz!
quiz: heart & circulatory system
q.7 what parts act like doors that control blood flow in the heart?
a) valves
b) heart dams
c) kidneys
d) chambers

Explanation:

Heart valves open and close to direct blood flow. Heart dams is not a real term. Kidneys filter blood but are not in the heart. Chambers hold blood, they don't control flow like doors.

Answer:

A. Valves