Brachial Plexus (Introduction and Anatomy)

Fig. 28.1

Trunks: (a) superior trunk, (b) medial trunk, (c) inferior trunk, divisions and cords of the brachial plexus. (1) Suprascapular nerve, (2) musculocutaneous nerve, (3) axillary nerve, (4) radial nerve, (5) median nerve, (6) ulnar nerve, (7) medial antebrachial cutaneous nerve, (8) medial brachial cutaneous nerve (With permission from Danilo Jankovic)

Fig. 28.2

Interscalene region. (1) Scalenus anterior muscle, (2) scalenus medius muscle, (3) trunks of the brachial plexus with subclavian artery, (4) proximal supraclavicular plexus sheath, (5) phrenic nerve, (6) ascendent cervical artery, (7) clavicle (With permission from Danilo Jankovic)

Fig. 28.3

Brachial plexus sheath extending from interscalene to subclavian and axillary region. Pectoralis muscle separated. (1) Middle and anterior scalene muscles, (2) trunks of the brachial plexus, (3) sternocleidomastoid muscle, (4) clavicle, (5) infraclavicular region, (6) axillary part of the brachial plexus, (7) deltoid muscle (With permission from Danilo Jankovic)

In the axilla itself, the nerve cords regroup and separate into the individual nerves (Fig. 28.4).

Fig. 28.4

Regrouping of the nerve cords in the area of the axilla and their distal distribution. (1) Lateral cord, (2) musculocutaneous nerve, (3) posterior cord, (4) medial cord, (5) median nerve, (6) radial nerve, (7) ulnar nerve (With permission from Danilo Jankovic)

The ventral branches of the superior and middle trunk combine to form the lateral cord (fasciculus lateralis, C5, C6, C7) (Figs. 28.5, 28.6, and 28.9).

Fig. 28.5

Fascicles (Cords) of the brachial plexus. Lateral cord (white), posterior cord (blue), medial cord (green), axillary artery (red). (1) Trunks of the brachial plexus above the clavicle (2), deltoid muscle (3). Pectoralis major muscle separated (With permission from Danilo Jankovic)

Fig. 28.6

Musculocutaneous nerve (yellow), and median nerve (green), axillary artery (red). (1) deltoid muscle, (2) biceps brachii muscle and coracobrachialis muscle, (3) latissimus dorsi muscle, (4) clavicle (With permission from Danilo Jankovic)

The following nerves emerge from this: