BRACHIAL PLEXUS : ANATOMY

Dr. Utsav Agrawal

Brachial plexus is formed by the anterior primary rami of C5,6,7,8 & T1

It consists of roots, trunks, cords, divisions and branches.

A total of 17 branches are given off from the plexus including 2 from roots, 2 from trunks and 13 from cords.

Pre-fixed P0st-fixed

C5>15%T1<13%

C5-6.8 to 12%T1 – 13.4 to22.4 %

The RootsContributions from Ventral primary rami of

C5, 6,7,8, and T1May be pre-fixed or post-fixed

Braches from roots – Dorsal scapular nerveLong thoracic nerve

Dorsal scapular nerveRoot value – C5Innervation – Rhomboideus major and minorFunction - Retraction of scapula

Long thoracic nerve‘Nerve of Bell’Root Value – C5, C6, C7Innervation – Serratus anteriorPalsy – Winging of scapula

- Loss of overhead abduction

The TrunksRoots from C5 and C6 join to form upper trunkC7 forms middle trunk C8 and T1 forms lower trunk

Branches from trunksSuprascapular nerve (C5,C6)Nerve to subclavius (C5,C6)

• Each trunk divides to form ventral and dorsal divisions which join to form cords

CordsVentral divisions of upper and middle trunks Lateral cord

Ventral division of lower trunk Medial cord

Dorsal divisions of all three trunks Posterior cord

Branches from cord

Lateral Cord Root Value – C5, C6, C71.> Lateral pectoral 2.> Lateral root of median 3.> Musculocutaneous – biceps, brachialis,

coracobrachialis

Medial CordMedial Pectoral (C8, T1)Medial cutaneous nerve of arm (C8, T1)Medial cutaneous nerve of forearm (C8,T1)Medial root of median (C8,T1)Ulnar (C7,8,T1)

Posterior cordUpper subscapular (C5,6)Lower subscapular (C5,6)Thoraco-dorsal (C6,7,8)Axillary ( C5,6)Radial (C5,6,7,8,T1)

Sensory

Relations

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