Which term indicates a direction towards the lower surface?

The term "ventral" refers specifically to the lower surface or belly side of an organism. In anatomical terminology, "ventral" is used to describe structures that are located toward the front or bottom of an organism, particularly in bilateral symmetrical organisms like humans. This directional term becomes especially significant in the context of anatomy and physiology, as it helps clarify the relative positions of various body structures.

In contrast, the other terms have distinct meanings: "dorsal" describes the upper surface or back side, "anterior" refers to the front of the organism, and "lateral" indicates a position away from the midline of the body, towards the sides. Each of these terms serves its own purpose in anatomical context but does not signify a direction toward the lower surface like "ventral" does.