ANATOMY

Detailed explanation-1: -Tricuspid valve: This valve has three leaflets. They allow blood to flow from the right atrium to the right ventricle. They also prevent blood from flowing backward from the right ventricle to the right atrium.

Detailed explanation-2: -When the ventricles contract, atrioventricular valves close to prevent blood from flowing back into the atria. When the ventricles relax, semilunar valves close to prevent blood from flowing back into the ventricles.

Detailed explanation-3: -The semilunar valves permit blood to flow into the arteries from the ventricles and prevent the backward flow of blood from the arteries into the ventricles.

Detailed explanation-4: -The aortic and pulmonic valves close preventing backward blood flow into the heart. The mitral and tricuspid valves then open to allow forward blood flow within the heart to fill the ventricles again.

Detailed explanation-5: -As the ventricles contract, ventricular pressure exceeds arterial pressure, the semilunar valves open and blood is pumped into the major arteries. However, when the ventricles relax, arterial pressure exceeds ventricular pressure and the semilunar valves snap shut.