<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>
mostly collagen and some calcium phosphate
Answer: They usually run tests too see. For example, that's why they made blood tests. They take you blood from you, and run tests to see if you have a disease.
Explanation: Hope it helps!
