Heart walls of the heart to valves by cartilaginous connections called chordae tendinae. These muscles prevent the valves from falling too far back when they close. During the relaxation phase of the cardiac cycle, the papillary muscles are also relaxed and the tension on the chordae tendineae is slight. As the heart chambers contract, so do the papillary muscles. This creates tension on the chordae tendineae, helping to hold the cusps of the atrioventricular valves in place and preventing them from being blown back into the atria. Two additional semilunar valves sit at the exit of each of the ventricles. The
Hypoplastic right heart syndrome Expression of these genes expression is regulated by various processes, including transcription and growth factors, as well as proteins like fibrillin, Wnt, BMP2, BMP 4, BMP5, BMP7, which aid in different heart development features like the valves and septum, and other substances, such as retinoid and folic acid.[5] Crucial steps in heart formation are development of the ventricles and atrium formation, as well as septation and valve formation. Any disturbances of such processes may lead to various congenital heart diseases and defects that could be initiated by various genetic, epigenetic or environmental factors. The most common heart malformations from genetic