Distal

Distal (from Latin distare - to be distant, to stand apart; the opposite concept is proximal), a term for designating the position of various organs and structures in the bodies of organisms. The term distal is used to denote a point that is distant from some specific conventional point, in contrast to proximal points, which are adjacent to this given point. Most often, the term distal is used in anatomy to designate the position of organs on the sides of the median line of the body (for example, the fingers of the hand are distal in relation to the shoulder joint, which would be the proximal end of the arm). However, the term distal can also be used not only in relation to the median plane (thus, in the tentacles of a hydra, the free end is distal in relation to the body itself, while the base is proximal). Similarly, in spherical organisms, surface points are distal in relation to those lying more centrally. In sessile animals, the free end of the body in its relation to the substrate can be called distal regardless of whether it is anterior or posterior. The position of various organs is sometimes considered distal or proximal in relation to the anterior pole of the body, with posterior organs being distal compared to those lying anterior.