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The triceps arm (shoulder triceps)
Last reviewed: 18.10.2021
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The triceps brachii muscle (m.triceps brachii) is thick, occupies the entire posterior surface of the shoulder, has three heads. The lateral and medial heads begin on the humerus, and the long ones on the shoulder blade.
The lateral head (caput laterale) begins with tendon and muscle tufts on the outer surface of the humerus, between the place of attachment of the small round muscle - proximally and the furrow of the radial nerve - distally, and also on the posterior surface of the lateral intermuscular septum. The bunches of the lateral head pass downward and medially, covering the furrow of the radial nerve with the nerve of the same name and the deep vessels of the shoulder.
The medial head (caput mediale) has a fleshy origin on the posterior surface of the shoulder between the place of attachment of the large round muscle and the fossa of the ulnar process; begins also on the medial and lateral intermuscular septa below the furrow of the radial nerve.
The long head (caput longum) begins with a strong tendon on the subarticular tubercle of the scapula and, continuing into the muscular abdomen, runs down between the small and large round muscles to the middle of the posterior surface of the shoulder, where its bundles connect to the beams of the lateral and medial heads. The muscle formed as a result of the connection of the three heads passes into a flat broad tendon, which is attached to the ulnar process of the ulna. Some of the bundles are woven into the capsule of the elbow joint and into the fascia of the forearm.
Function of the triceps brachii muscle (triceps pelchev): unbends the forearm in the elbow joint; The long head also acts on the shoulder joint, participating in the extension and bringing the shoulder to the trunk.
Innervation of the triceps arm (triceps pelchea): radial nerve (CV-CVIII).
Blood supply of the triceps arm muscle (triceps pecha): deep artery of the shoulder, posterior artery surrounding the humerus, upper and lower collateral ulnar arteries.