Brachial Plexus Flashcards
Where are the parts of the brachial plexus?
Roots - exit from IV foramina between scalenus anterior and medius
Trunks - base of the posterior triangle of the neck, behind the 3rd part of the subclavian artery
Divisions - behind the middle 1/3 of the clavicle
Cords - related to the 2nd part of the axillary artery
What are the sections of the brachial plexus?
Roots, trunks, divisions, cords, branches
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How many roots are there in the brachial plexus and what nerves do they give off?
5 C5- T1
C5 gives rise to Dorsal scapular nerve
Contribution to phrenic nerve
Branches from C5- C7 form the long thoracic nerve
What branches do they trunks of the brachial plexus give off?
Superior trunk gives off the suprascapular nerve and the nerve to subclavius
The middle and inferior trunks do not give off any branches
What branches do the cords of the brachial plexus give off?
Lateral cord - lateral pectoral nerve
Posterior cord - axillary nerve, superior subscapular nerve, thoracodorsal nerve, inferior subscapular nerve
Medial cord - Medial pectoral nerve, medial cutaneous nerve of the arm, medial cutaneous nerve of the forearm
What is an Erb’s palsy?
Damage to the upper nerve roots of the brachial plexus C5 and C6
Motor affection - Waiter’s tip deformity
- paralysis of the arm abductors (supraspinatus, deltoid) > adduction
- paralysis of arm external rotators (infraspinatus and teres minor) > internal rotation
- paralysis of forearm flexors and supinators (biceps, brachialis, brachioradialis > forearm extension
Sensory affection - loss of sensation of the radial side of the arm and forearm
What is a Klumpke’s palsy?
Injury to the lower trunk (C8 T1) of the brachial plexus
Motor affection - claw hand deformity
- paralysis of all intrinsic muscles of the hand
- paralysis of wrist flexors (except flexor carpi radialis)
- hyperextension of MCP joints with flexion of IP joints
Sensory affection - loss of sensation over ulnar border of forearm and hand
