Apical

Apical (or the apex) refers to the tip of a rounded or pyramid-shaped structure. It usually faces opposite the base of that specific body part.

For instance, the apical part of the lung lies at the level of the inlet of thoracic cavity, and it faces opposite the base of the lung which lies on the diaphragm. Similarly, apex of the heart lies at the level of left fifth intercostal space and it faces opposite the base which is formed by atria and lies at the back of the heart.