Coracobrachialis muscle

Coracobrachialis muscle
Deep muscles of the chest and front of the arm, with the boundaries of the axilla. Coracobrachialis is shown in blue.
Front of right upper extremity. (Coracobrachialis labeled at right, fourth from the bottom.)
Latin musculus coracobrachialis
Gray's subject #124 443
Origin coracoid process of scapula
Insertion    medial humerus
Artery brachial artery
Nerve musculocutaneous nerve (C5, C6, and C7)
Actions adducts humerus , flexes the arm at glenohumeral joint

The Coracobrachialis is the smallest of the three muscles that attach to the coracoid process of the scapula. (The other two muscles are pectoralis minor and biceps brachii.) It is situated at the upper and medial part of the arm.

It is perforated by and innervated by the musculocutaneous nerve.

Contents

Origin and insertion

It arises from the apex of the coracoid process, in common with the short head of the Biceps brachii, and from the intermuscular septum between the two muscles.

It is inserted by means of a flat tendon into an impression at the middle of the medial surface and border of the body of the humerus (shaft of the humerus) between the origins of the Triceps brachii and Brachialis.

Action

The coracobrachialis draws the humerus forward (shoulder flexion) and towards the torso (shoulder adduction).

Innervation

The coracobrachialis muscle is innervated by the musculocutaneous nerve which arises from the anterior division of the upper (C5, C6) & middle trunks (C7) of the brachial plexus.

Additional images

External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.