Final answer:
The aortic semilunar valve serves as the outflow tract of the left ventricle, allowing blood to exit to the aorta and preventing backflow into the ventricle upon relaxation. It is one of the four critical valves in the heart, necessary for unidirectional blood flow and the systemic circulation process in mammals.
Step-by-step explanation:
The aortic semilunar valve is the outflow tract of the left ventricle. Its primary function is to eject blood into the aorta during the contraction of the left ventricle and to prevent blood from flowing backwards into the ventricle when it relaxes. This valve is crucial for maintaining a unidirectional flow of blood and is essential for the proper function of the systemic circulation. The aortic valve, typically comprised of three cusps, closes when the left ventricle relaxes, preventing backflow of blood into the ventricle, a process that is part of the double circulation system found in all mammals.
In contrast, the right ventricle pumps deoxygenated blood through the pulmonary semilunar valve, also known as the pulmonary or pulmonic valve, to the lungs for oxygenation. The naming of the valves is indicative of their position and function within the heart's anatomy. For instance, the tricuspid valve is the atrioventricular valve on the right side of the heart, and the bicuspid valve, also called the mitral valve, is the atrioventricular valve on the left side.