Heart valves.
They are structures that ensure unidirectional flow of blood within the heart. They are 4 valves divided into 2 groups: AV valves, and SL valves.
AV valves.
They are the valves between the atria and ventricles, closing during ventricular systole giving the first heart sound.
Tricuspid valve.
- Between right atrium and ventricle.
- Made of 3 cusps: anterior, septal, and posterior.
- Free edges of cusps are attached to chorda tendinea and 3 papillary muscles.
Mitral valve.
- Between left atrium and ventricle.
- Made of 2 cusps: anterior and posterior.
- Free edges of cusps are attached to chorda tendinea and 2 papillary muscles.
SL valves.
They are valves between the ventricles and their associated vessels, closing during ventricular diastole giving second heart sound.
Pulmonary valve.
- Between right ventricle and pulmonary trunk.
- Made of 3 cusps: left, right, and anterior.
Aortic valve.
- Between left ventricle and the aorta.
- Made of 3 cusps: right, left, and posterior.
- Area around cusps is slightly dilated creating a sinus.
- Free edges are thickened (lunule) middle is wide (nodule).
