In anatomy, the dorsum is the upper or back side of an animal, as opposed to the ventrum. In vertebrates, it contains the backbone. In fishes, it refers to the top, front fin (see Dorsal fin). It is the anatomical opposite of ventral (referring to the front or underside of an animal).

In lepidoptera, the dorsum also refers to the trailing edge of the wing (the leading edge is called the costa).

Dorsum and dorsally are derivatives of this word and refer to anatomical structures that are either toward the back (backbone) or off the back side of an animal. The names of some structures have even had dorsal (or a form of dorsal) incorporated into them. Examples of this include the dorsal fin, dorsal root ganglion, dorsal root, dorsal nerve, dorsum sellae, dorsal arch, dorsalis pedis arteries, dorsal ramus, dorsal respiratory group, dorsal venous arch, and dorsiflexion among others.

See also

• Anatomical terms of location