EM 370 Heart

Heart Valve

Scanning electron microscopy (SEM) of the tricuspid valve of the right ventricle of the heart.

The heart utilizes one-way valves to ensure unidirectional blood flow through its four chambers. The tricuspid valve is located on the right side of the heart, allowing blood to flow between the right atrium and the right ventricle.

• Tricuspid Valve (yellow): Composed of three fibrous cusps (or leaflets) that open to allow blood into the ventricle and snap shut to prevent backflow into the atrium during contraction
• Chordae Tendineae (cyan): Tough, fibrous cords that anchor the valve leaflets to the papillary muscles (missing for the visible ones)
• Papillary Muscles (orange): Project from the ventricular wall and contract during ventricular contraction (systole) to provide tension that prevents the leaflets from prolapsing back into the right atrium under high pressure
• Cardiac Muscle/Myocardium (red): Thick muscular layer that provides the force necessary to pump blood into the lungs

The inner surface of the heart, including the valves and chambers, is lined with endocardium, a smooth layer that minimizes friction and prevents blood clotting.