Posterior compartment of arm

Question 1

Triceps:
* Origin
* Insertion
* Nerve supply
* Action

Answer 1

• Origin - long head - infraglenoid tubercle of the scapula. Lateral head - posterior aspect of the humerus, superior to the radial groove. Medial head - posterior aspect of humerus, inferior to the radial groove.
• Insertion - posterior surface of the olecranon process of the ulna and capsule of the elbow joint.
• Nerve supply - radial nerve (C7, 8).
• Action - elbow extension. The long head supports the capsule of the shoulder joint when the arm is abducted, and it aids in extending the shoulder joint.