innervated by has muscle origin has muscle insertion has muscle antagonist humerus muscle of shoulder radial nerve axillary nerve biceps brachii triceps brachii Wikipedia:Triceps_brachii_muscle musculus triceps brachii VHOG:0000851 SCTID:181623009 MA:0002399 triceps EHDAA2:0002080 The triceps brachii muscle (Latin for 'three-headed' muscle of the arm, it is called a three headed muscle because there are three bundles of muscle, each of different origin, joining together at the elbow) is the large muscle on the back of the human upper limb. It is the muscle principally responsible for extension of the elbow joint (i.e. straightening of the arm). Though a similarly-named muscle, the triceps surae, is found on the lower leg, the triceps brachii is commonly called simply the 'triceps'. [WP,unvetted]. triceps muscle Dorsal group derivative that acts on the forearm[Kardong] triceps brachii muscle NCIT:C90604 UBERON:0001509 EHDAA:8287 FMA:37688 EMAPA:19111 NCIT:C33812 forelimb stylopod muscle olecranon scapula scapular muscle