What are the thin bands of fibrous tissue that attach to the valves in the heart and prevent them from inverting?

The thin bands of fibrous tissue that attach to the heart valves and prevent them from inverting are known as chordae tendineae. These structures play a critical role in the proper functioning of the heart’s valves, specifically the atrioventricular valves (the mitral and tricuspid valves). When the heart contracts, the pressure change pushes the valve cusps open, and the chordae tendineae, along with the papillary muscles to which they are attached, work to ensure that the valves remain closed during ventricular contraction. This prevents backflow of blood into the atria and ensures efficient blood flow through the heart and into the arteries.

In contrast, myocardium refers to the muscular tissue of the heart, responsible for its contraction and the pump function, but does not have a specific role in valve function. The aorta is the main artery that carries blood away from the heart to the rest of the body, while the endocardium is the inner lining of the heart chambers and valves, which helps reduce friction as blood flows through the heart. These terms denote different structures or functions and are not involved in the function of preventing valve inversion like the chordae tendineae do.