ventral

Ventral is an anatomical directional term used to describe the underside or belly side of an organism. In humans it corresponds to the anterior or front of the body, while in many other animals it denotes the belly-facing surface. The word comes from the Latin venter, meaning belly. The term is used to describe surfaces, organs, or structures that face the ventral aspect of the body, in contrast to dorsal, which refers to the back.

In the nervous system, ventral can have several distinct meanings. In many invertebrates, the ventral nerve cord runs along the belly side, contrasting with a dorsal nerve cord found in chordates. In vertebrates, spinal nerves have ventral and dorsal roots, with motor (efferent) fibers typically exiting through the ventral roots and sensory (afferent) fibers entering through the dorsal roots. The ventral side of organs and structures is described in relation to their location within the body cavity or on the body surface.

Clinical and developmental usage includes ventral hernias, which involve the anterior abdominal wall, and references to ventral surfaces in embryology and anatomy. The ventral body cavity, the major internal space on the ventral side, houses the thoracic and abdominopelvic cavities. While commonly applied to humans, ventral terminology is widely used across zoology and anatomy to describe front-facing or belly-oriented structures, with orientation clarified by anatomical context.