What is so special about the level of the coracobrachialis insertion? Several important things happen at the level of the coracobrachialis insertion. These are high yield facts that students are commonly tested on.
Arteries
- The brachial artery passes from the medial side of the arm to the anterior compartment
- The nutrient artery of the humerus enters the bone.
- The superior ulna collateral vessels pierce the medial intermuscular septum with the ulna nerve.
- The profunda brachii vessels follow the radial nerve
Veins
- The basilic vein pierces the deep fascia. (Basilic vein is a superficial vein, and it joins the deep brachial vein after entering the deep fascia.)
Nerves
- The median nerve crosses the brachial artery from lateral to the medial side, anteriorly.
- The Ulnar nerve pierces the medial intermuscular septa to enter the posterior compartment.
- The radial nerve pierces the lateral intermuscular septum to enter into the anterior compartment.
- The median cutaneous nerve of the arm/ forearm, pierces the deep fascia.
Muscles
- The deltoid muscle inserts into the deltoid tuberosity.
- The origin of the brachialis muscle is also found at this level
Bones
- The humerus is circular in cross-section if cut above this level, and it is triangular in cross-section below this level. The transition from circular to triangular happens at this level
Fascial Septa
- Medial and lateral intermuscular septa become prominent starting from this level and going downwards.
