Minor Nerve Distribution of Brachial Plexus

 

Minor Branches of Brachial Plexus

There are a number of minor nerves that emerge from the brachial plexus in addition to the five major branches which we discuss in previous brachial plexus topic . They can do so from any of the five sections of the brachial plexus, as described below:

 

Roots

Dorsal Scapular nerve 

•Originate From C5 nerve root.

•The Rhomboid major, Rhomboid minor, and levator scapulae muscles are all innervated by the dorsal scapular nerve, which is a motor nerve. 

•These muscles work together to elevate and retract the scapula.

 

Long Thoracic nerve

•Also know as nerve of bell.

•Originate from C5, C6, C7 nerve root. 

•The serratus anterior muscle, which is one of the most important muscles for rotating the scapula and elevating the arm, is innervated by the long thoracic nerve, which is motor nerve.

 

Trunks 

Supra-scapular nerve

•Originate from C5, C6 nerve root in Upper (Superior) trunk of brachial plexus.

•Its mixed nerve provide motor innervation to two muscles: the supraspinatus and infraspinatus muscles. 

•The supra-scapular nerve also gives sensory input to the shoulder joints (the glenohumeral and acromioclavicular joints).

 

Subclavian nerve

•Originate from C5, C6 nerve root in Upper (Superior) trunk of brachial plexus.

•Its innervate to Subclavius muscle, which is responsible to stabilize clavicle during movement of shoulder girdle.

 

Cords

Lateral Cord:- 

Lateral pectoral nerve

•Originate from C5, C6, C7 nerve root in lateral Cord of brachial plexus.

•Its motor nerve innervate to the pectorals major and minor muscles, which is responsible for adduction, flexion and medial rotation of arm. 

 

Medial Cord:-

Medial Pectoral nerve

•Originate from C8, T1 nerve in between Lower (inferior) trunk and medial cord of brachial plexus.

•Its motor nerve innervate to the pectorals major and minor muscles, which is responsible for Adduction, flexion and medial rotation of arm.

 

Medial Cutaneous nerve of arm

•Originate from C8, T1 nerve root in medial cord of brachial plexus.

•Its smallest sensory nerve which provide sensation to medial side of arm.

 

Medical Cutaneous nerve of forearm

•Originate from C8, T1 nerve root in medial cord of brachial plexus.

•Its smallest sensory nerve which provide sensation to medial side of forearm.

 

Posterior Cord:-

Superior (Upper) sub-scapular nerve

•Originate from C6, C7, C8 nerve root in posterior cord of brachial plexus as a result of upper, middle and lower trunk attachment.

•Its innervate the superior portion of sub scapularis muscle.

 

Thoracodorsal nerve 

•Originate from C6, C7, C8 nerve root in posterior cord of brachial plexus as a result of upper, middle and lower trunk attachment.

•Its motor nerve innervates in the latissimus dorsi muscle. 

 

Inferior (lower) sub-scapular nerve

•Originate from C6, C7, C8 nerve root in posterior cord of brachial plexus as a result of upper, middle and lower trunk attachment.

•Its innervate the inferior portion of sub scapularis muscle.