What is the name of the pouch-like dilation behind each aortic valve cusp?

The pouch-like dilation behind each aortic valve cusp is known as the Sinus of Valsalva. This anatomical structure is formed where the aorta rises from the heart and is situated just above the aortic valve. Its primary function is to accommodate the flow of blood from the heart during systole and to help maintain hemodynamic stability. The Sinus of Valsalva plays a crucial role in the regulation of blood flow and valve function by allowing for a smooth transition of blood from the aorta into the systemic circulation.

The other options refer to different cardiac structures: the fossa ovalis is a depression in the right atrium, a remnant of the foramen ovale; the right atrium is one of the four heart chambers responsible for receiving deoxygenated blood from the body; and the left atrium is another heart chamber that receives oxygenated blood from the pulmonary veins. These structures do not share the same functional or anatomical characteristics as the Sinus of Valsalva, which specifically pertains to the aortic valve area.