dorsum

Dorsum is a noun in anatomy and biology derived from the Latin dorsum, meaning back. It denotes the back or posterior surface of an organism or of a specific body part, as opposed to the ventrum, which is the underside. In medical and anatomical terminology, dorsum can refer to the dorsal aspect of the body as a whole or to the upper surface of a particular organ or structure.

In humans and many animals, the term is used in standard phrases that describe specific surfaces. For example, the dorsum manus refers to the back of the hand, the dorsum pedis to the top surface of the foot, and the dorsum linguae to the upper surface of the tongue. The dorsum of an organ indicates its superior or back-facing aspect, the side oriented away from the belly or chest. The use of dorsum is common in anatomical descriptions across species, including the skull and other skeletal elements.

Several anatomical terms explicitly use dorsum to name a surface or edge. A notable example is the dorsum sellae, a bony ridge on the sphenoid bone that forms part of the sella turcica. This term illustrates how dorsum is applied to specify a particular back-facing surface within a complex structure. Etymologically, dorsum consistently reflects the concept of a back or dorsal surface across anatomical contexts.