Superficial

In anatomy, superficial is a directional term that indicates that one structure is located more externally, or closer to the surface of the body, than another.

The opposite of superficial is deep. For example, the spine is deep in the body, while the skin is superficial. The term superficial is not limited to structures on the very outside of the body, such as the skin or eyes. It can also refer to structures inside such as bones, muscles and more when those structures are more superficial than a point of reference.