Overview
It fills the angle between the caudal border of the scapula and the humerus. In cattle it has three heads ending on the olecranon: long, lateral and medial. The long head is the bulkiest.
Origin
- Long head (caput longum): caudal border of the scapula. The only head that crosses the shoulder.
- Lateral head (caput laterale): tricipital line on the lateral surface of the proximal humerus.
- Medial head (caput mediale): medial surface of the humerus.
Insertion
Olecranon tuber (tuber olecrani) of the ulna.
Action
Extends the elbow and supports body weight when standing. The long head also flexes the shoulder.
Innervation
Radial nerve (n. radialis).
Clinical relevance
In radial nerve paralysis, from humeral fractures or compression during prolonged lateral recumbency, the triceps is inactive: the elbow drops, the animal cannot bear weight on the limb and knuckles over onto the dorsal surface of the hoof.