Even in the earliest writings on the subject, the idea was expressed that vibrations due to the opening of the semilunar valves took part in the formation of the first sound (Cruveilhier ...

It likewise opens due to a build-up of pressure, this time in the left atrium. The semilunar valves stop the back flow of blood into the heart. There is a semilunar valve where the aorta leaves ...

The bicuspid valve is located between the left atrium and left ventricle and likewise opens due to a build-up of pressure, this time in the left atrium. The semilunar valves stop the back flow of ...