Which rib is the base of the heart located below?

The heart, specifically its base, is situated at approximately the level of the second rib. The base of the heart primarily refers to the area where the great vessels emerge, and it is positioned in relation to the ribcage. The second rib aligns with the sternal angle, which is an important landmark indicating the level of the heart in the thoracic cavity.

Anatomically, the heart rests above the diaphragm and is located between the lungs, but it is specifically oriented so that its apex points downward and slightly left, with its base facing more posteriorly and vertically. By understanding the position of the heart in relation to the skeletal structures of the chest, it becomes clear that the second rib serves as the primary anatomical landmark below which the base of the heart is located.