Extrinsic

Not contained in or belonging to a body; external; outward; unessential; -- opposed to intrinsic.

Attached partly to an organ or limb and partly to some other part/ -- said of certain groups of muscles. Opposed to intrinsic.

not forming an essential part of a thing or arising or originating from the outside; "extrinsic evidence"; "an extrinsic feature of the new building"; "that style is something extrinsic to the subject"; "looking for extrinsic aid"