What is a "valve "?

A valve refers to a structure that regulates the flow of fluids or substances within various systems. In particular, valves in the cardiovascular system play a crucial role in directing the flow of blood. These valves, such as the atrioventricular (AV) valves and semilunar valves, ensure that blood flows in the desired direction and prevents backflow. Valves also exist in other parts of the body, such as the digestive system, where they control the passage of food and waste materials. Overall, valves act as important gatekeepers, maintaining the proper flow and function of fluids and substances within the body.