Triceps brachii

Dr Henry Knipe et al.

The triceps brachii, which often referred to simply as the triceps is a three-headed muscle in the posterior compartment of the arm.


  • origin
    • long head: infraglenoid tubercle of the scapula
    • medial head: posterior humerus, inferior to the radial groove, medial intermuscular septum
    • lateral head: posterior and lateral humerus, superior and lateral to the radial groove, lateral intermuscular septum
  • insertion: proximal olecranon of the ulna and deep fascia of arm
  • blood supply: branches of deep brachial artery
  • innervation: radial nerve, branches of ulnar nerve
  • actions

Variant anatomy

  • a patella cubiti may be present (very rare)
  • 4th head from medial humerus
  • slip termed dorso-epitrochlearis extending between triceps and latissimus dorsi
Anatomy: Upper limb
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Article information

rID: 23235
Section: Anatomy
Synonyms or Alternate Spellings:
  • Triceps brachii muscle

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