Coracobrachialis

The coracobrachialis is a deep, spindle-shaped muscle of upper portion of arm. It lies beneath the short head of the biceps brachii muscle. Lying on the medial side of proximal portion of humerus, it arises from the apex of the coracoid process of scapula. Then it extends down along the upper part of humerus to be inserted into the medial surface of this bone, on the medial lip of the bicipital groove.

Action

The coracobrachialis muscle raises and adducts the arm (pulls it towards the side of trunk).

Innervation

This hidden muscle is innervated by side branches from the musculocutaneous nerve.

Blood Supply

It receives oxygenated blood from secondary branches of the deep brachial and brachial artery.

Below, the coracobrachialis muscle hidden by biceps brachii.

The coracobrachialis, with the bicepss brachii muscle romoved. You can also see the musculocutaneous nerve and brachialis muscle on the lower portion of humerus.

Below, another view of coracobrachialis, along with pectoral major muscle.