Question

Which structure of the heart acts like an automatic door that closes once blood enters a chamber and forces it to exit in the proper direction. A. Atria C. Arteries B. Valves D. Ventricles

Answer 1

anwser is B: valves

Step-by-step explanation:

Answer 2

valves, they are like flaps of muscle that keeps the blood in its place util its ready to be pumped along.