Brachial plexus is the plexus of nerves formed by anterior (ventral) rami of last four cervical and first thoracic spinal nerves. (C5, C6, C7, C8, T1) It is divided into five subunits:

  • Roots
  • Trunks
  • Division
  • Cords
  • Branches

Mnemonics :- Randy Travis Drinks Cold Beer

ROOTS:- They constitute anterior primary rami of C5 to T1 spinal nerves. They are located in the neck.

Upper trunk:- is formed by the union of C5 and C6 root.
Middle Trunk :– is formed by C7 alone.
Lower trunk:-is formed by union of C8 and T1 roots. They also located in the neck.

DIVISIONS:- Each trunk is divided to form anterior and posterior divisions.They are located behind clavicle.

CORDS:- Lateral cord is formed by union of anterior division of upper and middle trunk.
Medial cord is continuation of anterior division of lower trunk Posterior cord is formed by union of posterior division of all trunks. Cords are located in the axilla


Branches of Brachial Plexus:-

(A) FROM ROOTS :- (1) Long thoracic nerve (2) Dorsal scapular nerve


  • Suprascapular nerve
  • Nerve to subclavius


From lateral cord :-

  • Lateral pectoral nerve
  • Lateral root of median nerve
  • Musculocutaneous nerve

From medial cord :-

  • Medial pectoral nerve
  • Medial cutaneous nerve of arm
  • Medial cutaneous nerve of forearm
  • Medial root of median nerve
  • Ulnar nerve

From posterior cord:-

  • Radial nerve
  • Axillary nerve
  • Thoracodorsal nerve
  • Upper subscapular nerve
  • Lower subscapular nerve

Mnemoics :- Branches of posterior cord


  • Subscapular (upper and lower)
  • Thoracodorsal
  • Axillary
  • Radial


  1. Erb’s paralysis
  2. Klumpke’s paralysis

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