Answer:
B
Explanation:
BBBBBBBBBBBBBB BBBBBBBBBBBB THE ANSWER I THINK IS B
<span>Unidirectional flow in the heart is ensured because the heart contains valves that prevent backflow.
These valves keep the flow of the heart going in one direction (hence the name "unidirectional").</span>
These are called papillae
Homogeneous is the answer