Dorsal

The back or posterior side of a structure.

"Dorsum" is the Latin word for the back.

Something pertaining to the dorsum is dorsal.

The dorsal surface of the hand is the back of the hand, the side opposite the palm.

The dorsal surface of the foot is the back of the foot, the side opposite the sole.

The dorsal vertebrae are the thoracic vertebrae; they form part of the back.

The dorsal roots of the spinal nerves are the back roots, the posterior roots.

The opposite of dorsum is ventrum which comes from the Latin "venter" meaning belly.

Something that is ventral is oriented toward the belly, toward the front of the body.