Pulmonary Valve
The structure indicated is the
pulmonary valve. There are four sets of valves in the heart. Between the atria and the ventricles are the
atrioventricular valves; on the right is the
tricuspid valve, on the left is the
mitral (bicuspid) valve. Between the ventricles and the aorta/pulmonary trunk are the
semilunar valves. The pulmonary valve is located between the right ventricle and the pulmonary trunk, and the aortic valve is located between the left ventricle and the aorta. The pulmonary valve (pulmonic valve) has
three cusps. The pulmonary valve opens in ventricular systole, when the pressure in the right ventricle becomes greater than the pressure in the pulmonary trunk, thereby forcing the valve open. At the end of ventricular systole, the pressure in the right ventricle falls, and the pressure in the pulmonary trunk is greater, thereby forcing the closure of the pulmonary valve. The three cusps of the pulmonary valve are:
- Left cusp
- Right cusp
- Anterior cusp
The free superior edge of these cusps thickens in the middle to form a
nodule, laterally it is thinner and is called the
lunule. Learn more about the anatomy of the heart in these tutorials:
