Triceps Brachii

The triceps brachii is a muscle in the posterior compartment of the upper arm. It is a large horseshoe-shaped muscle, which forms the majority of the muscle bulk of the upper arm.

• Attachments: 
  • Long head originates from the infraglenoid tubercle of the scapula.
  • Lateral head originates from the humerus (superior to the radial groove).
  • Medial head originates from the humerus (inferior to the radial groove).
  • Distally, the heads converge into one tendon which inserts onto the olecranon of the ulna.
• Function: Extension of the arm at the elbow.
• Blood Supply: Deep bracial (profunda brachii) artery
• Innervation: Radial nerve

By TeachMeSeries Ltd (2025)

Fig 1
The long and lateral heads of the triceps brachii.