ulna

[Lat., from Gr. ōlene =the elbow.] 1. Anat .: A long prismatic bone, at the inner side of the forearm, parallel with the radius, with which it articulates. It is the larger and longer of the two bones, and consists of a shaft and two extremities, the upper of which forms a large part of the articulation of the elbow-joint. At the upper extremity behind is a large proce , the olecranon, and a smaller one, the coronoid proce , in front, separated by the sigmoid or semi-lunar fo a, or olecranoid cavity, which receives the articular trochlea of the humerus. The ulna diminishes in size from above downward, and is very small at the lower extremity, which is separated from the twist by an inter-articular fibrocartilage. *2. Old Law : An ell. ŭl-năd, adv . [Eng., ., uln ( a ), and Latin ad =to, toward.] In the direction of the ulna; toward the ulnar aspect. ŭl-nar, a. [Lat. ulna =the elbow.] Anat.: Of or pertaining to the ulna. ulnar-artery, s. Bones of Arm and Hand. a. Humerus; b. Radius; 0. Ulna; d. Carpus; e. Metacarpus; f. Phalanges. Anatomy : The larger of the two branches into which the brachial artery divides. It commences just below the bend of the elbow, and runs along the inner side of the forearm, in an arched direc tion and at varying depth, to the hand, where it forms the superficial palmar arch. It gives off several branches. ulnar-nerve, s. Anat .: A branch of the brachial plexus, distributed to the muscles and integument of the forearm and hand.