Final answer:
In the heart's standard anatomical views, the two aortic valve leaflets typically observed are the right coronary cusp and the left coronary cusp. The noncoronary cusp is less commonly visible in such views. The aortic valve opens to allow blood to pass from the left ventricle into the aorta.
Step-by-step explanation:
The aortic valve is one of the two semilunar valves in the human heart, the other being the pulmonary valve. While viewing the heart as indicated in the query, assuming we are looking at standard anatomical views such as the transverse section or frontal view, generally, the two aortic valve leaflets that are most readily seen would be the right coronary cusp and the left coronary cusp. The third cusp, the noncoronary cusp, is often not as visible in these perspectives. It's important to note that in some medical imaging techniques like echocardiograms, the visibility of the leaflets can be variable depending on the angle of the image.
The aortic valve's role in cardiovascular function is critical—it opens to let oxygenated blood from the left ventricle be ejected into the aorta, the body's main artery. During ventricular relaxation, as described in Figure 19.13a, the semilunar valves (which include the aortic valve and the pulmonary valve) are closed to prevent backflow of blood into the ventricles.