Posterior Compartment Of The Forearm

Posterior Compartment of The Forearm

Question 1. Enumerate the contents of the posterior compartment of the arm.
Answer.

The contents of the posterior compartment of the arm are:

• Triceps brachii muscle
• Radial nerve
• Profunda brachii artery

Posterior compartment of forearm

Question 2. Give the origin, insertion, nerve supply and actions of triceps brachii.
Answer.

Triceps Brachii Origin

Triceps brachii muscle arises by three heads – long, lateral and medial.

Triceps Brachii Long head:

From infraglenoid tubercle of scapula.

Triceps Brachii Lateral head:

From oblique ridge above the spiral groove (i.e. lateral lip of the spiral groove).

posterior compartment of forearm

Triceps Brachii Medial head:

Extensor muscles of forearm

From posterior surface of shaft of humerus below the level of spiral groove.

Triceps Brachii Insertion

Into the posterior part of the superior surface of olecranon process of ulna.

Triceps Brachii Nerve supply

Radial nerve (C7, C8).

Note. Each head is supplied by a separate branch. The branch supplying long head arises in axilla, the branch supplying lateral head arises in spiral groove and the branch supplying medial head arises both in axilla and spiral groove.

Triceps Brachii Action

Extensor of elbow.