Brachial Plexus

D.Rania GabrD.Sama-ul-HaqueD.Elsherbiny

Objectives

• Describe the brachial plexus• Make a list of contributing spinal nerves.• Discuss the general arrangement of this

plexus.• Locate the plexus in the axilla and note

important relations to blood vessels.• Make a list of the terminal main branches of

brachial plexus.

Location of Brachial plexus

Def: nerve supply of upper limb.

Formation: It is formed by the union of the anterior Rami of the C 5th, 6th, 7th & 8th and T1 spinal nerve.

Roots…….trunks……division……cords…..branches

Site: Roots & Trunks: in the posterior∆Divisions: behind the clavicle (in cervico-axillary canal).Cords & Branches: in the axilla

Brachial Plexus

Roots : C5,6,7,8 and T1.Trunk:1. Upper trunk: union of C5.62. Middle trunk: C7.3. Lower trunk : union of C8 and T1.Division; each trunk divides into anterior and posterior.Cords;4. Lateral cord: union of anterior division of upper and

middle trunk.5. Medial cord: anterior division of lower trunk.6. Posterior cord: union of posterior division of upper,

middle and lower trunk.

Brachial Plexus

(A) From Roots:1. C5: Nerve to rhomboids (dorsal scapular nerve).

2. C5,6 &7: Long thoracic nerve

(B) From Trunks (upper trunk):

1. Nerve to subclavius

2. Suprascapular nerve

Branches Brachial Plexus

Lateral Cord(2LM) .Lateral pectoral n.Lateral root to median n.Musculocutaneous n

Posterior Cord(ULTRA) .Upper subscapular n.Lower subscapular n.Thoracodorsal n.Radial n .Axillary n

Medial cord(4MU) .Medial pectoral n..Medial root to median n..Medial cutaneous n of arm..Medial cutaneous n of forearm..Ulnar n.

C5

C6

C7

C8T1

(C)Branches from the cords:

Lateral cord-3 Medial cord-5 Posterior cord-5

Lateral pectoral nerve. Medial pectoral nerve. Axillary nerve.

Musculocutaneous nerve. Ulnar nerve. Radial nerve.

Median nerve (lateral root). Median nerve (medial root). Upper & lower subscapular nerves.

Medial cutaneous nerve of arm & forearm.

Thoracodorsal or N. to latissimus dorsi.

Relations of Brachial plexus

MedialLateral Axillaryartery

Axillary vein

Posterior

Anterior

Medialcord

Posteriorcord

Lateralcord

Nerve injury is manifested by:1. Loss of sensation: in the area of cutaneous distribution.2. Paralysis of voluntary muscles supplied.3. Wasting of paralyzed muscles.

Brachial Plexus Injuries

Cause: Birth injury.The most commonly involved nerves:suprascapular nerve, musculocutaneous, and axillary nerve:Muscles atrophy:a. Muscles of shoulder.b. Flexors of elbow.c. Extensors of finger.

Lesions of the upper trunk C5,6ERB'S paralysis

Policeman (waiter) tips paralysisa. Adduction of the arm.b. Extension of the elbow.c. Pronation of the forearm.d. Flexion of the fingers.

Falling on Shoulder

Excessive Stretching

Direct Blow

Cause: Cervical rib (compression of the lower trunk and subclavian artery).Deformity: Flail (claw) hand.Muscles atrophy: All the intrinsic muscles of the hand.

Lesions of the lower trunk (C8,T1) Klumpke paralysis or Palsy

Baby’s upper limb is pulled excessively during delivery

Claw Hand