The pulmonary valve is one of the four main valves in the heart. It is located between the right ventricle and the pulmonary artery, which carries blood to the lungs. The valve opens to allow deoxygenated blood to flow from the heart to the lungs for oxygenation and closes to prevent backflow into the heart. This valve consists of three leaflets that work together to ensure proper blood flow. When the right ventricle contracts, the pulmonary valve opens, allowing blood to exit. When the ventricle relaxes, the valve closes, ensuring that blood does not return to the heart, maintaining efficient circulation.