Describe the structure and function of the heart valves

There are four heart valves in total. The triscuspid valve is between the right atrium and ventricle. The bicuspid valve is between the left atrium and ventricle. These are the atrioventricular valves and stop backflow of blood from the ventricles back into the atria. They are cuspid valves, meaning they consist of 2 or 3 cusps held in place by papillary muscle. The semilunar valves consist of the aortic and pulmonary valves, and stop blood flowing back into the ventricles after leaving the heart. When the pressure increases in the vessel due to blood flowing into it, the valve closes as blood tries to get back into the previous chamber of the heart.