Nerves of the Brachial Plexus

Responsible for cutaneous and muscular innervation of entire upper limb except for region of skin near axilla and upper trap. Emerges at 5 different levels C5-T1

There are 5 roots the anterior rami of the spinal nerves after they have given off their innervation to their segmental supply of the neck muscles

The 5 roots merge to form 3 trunks
The upper or superior C5-C6
middle C7
lower or inferior C8, T1

Each trunk splits into 2 to form 6 divisions
anterior division of upper, middle and lower
postioer division of upper, middle and lower

These 6 divisions will regroup to form three cords
The posterior cord is formed from the 3 posterior divisions
The lateral cord is formed from the anterior divisions of the upper and middle
The medial cord is a continuation of the anterior inferior division

Origin: C4, C5 (Rami)
Muscles: Rhomboids, Levator scapulae

Origin: C5, C6, C7 (Rami)
Muscles: serratus anterior

Origin: C5, C6 (upper trunk)
Muscles: subclavius

Origin: C5, C6 (upper trunk)
Muscles: Infraspinatus, Supraspinatus

Origin: C5, C6, C7 (lateral cord)
Muscles: Pectoralis major - clavicular head

Origin: C5, C6, C7 (lateral cord)
Muscles: Coracobrachialis, biceps brachii, brachialis

Origin: C5, C6, C7 (lateral cord)
Muscles: flexor muscles in the forearm, except flexor carpi unlaris and five muscles in the hand

Origin: C8, T1 (medial cord)
Muscles: pectoralis major, pectoralis minor

Origin: C8, T1 (medial cord)
Muscles: flexor carpi ulnaris, flexor digitorum profundus, small muscles of the hand

Origin: C8, T1 (medial cord)
Muscles: flexor muscles in the forearm, except flexor carpi ulnaris and five muscles of the hand