Final answer:
The term "distal" refers to a position that is farther away from the trunk of the body or from the point of origin of a body part, while "proximal" implies a closer position to these reference points.
Step-by-step explanation:
The word that means "farther away" or "farthest from" the trunk or the point of origin of a body part is distal. For example, the hand is distal to the forearm because it is farther away from the point of attachment to the trunk of the body. In contrast, proximal describes a position in a limb that is nearer to the point of attachment or the trunk of the body, such as the brachium being proximal to the antebrachium. Other anatomical terms like superficial and deep also describe positions relative to the surface of the body; superficial being closer, and deep being farther from the body's surface.
These terms are essential in the differentiation process, where unspecialized cells become specialized in structure and function within the body, requiring the clear identification of locations relative to other body parts. Knowledge of these terms, such as distal, proximal, superficial, and deep, is also foundational in fields such as gross anatomy, which studies the larger structures of the body.