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