In anatomical terms, what does "deep" refer to?

In anatomical terminology, the term "deep" is used to describe structures that are located further away from the body's surface, essentially extending inward in relation to a surface layer. This is crucial for understanding the three-dimensional orientation of various anatomical structures within the body. It contrasts with the term "superficial," which refers to structures that are closer to the surface. For instance, muscles located deeper within the body are considered deep relative to the skin and other superficial structures. The use of "deep" helps in accurately identifying the locations of organs, tissues, and other anatomical components in relation to one another, which is vital for effective communication in medical and anatomical discussions.