PNS Exam 3 Brachial plexus = Unit V notes

what does the brachial plexus supply

upper extremities

what is the brachial plexus formed by

anterior primary rami of C5-T1

what may the brachial plexus also receive fibers from when formed

C4 and/or T2

where does the brachial plexus travel in the body

laterally over rib 1 into the axilla

what are the sections the brachial plexus if broken into

-roots

-trunks

-divisions

-cords

-terminal nerves/branches

roots combine into ___________

trunks

trunks divide into _____________

divisions

divisions combine to form ______________

cords

cords divide into _____________________

terminal nerves

what is the last section of the brachial plexus

terminal branches

what will each root receive __________________ from ________________

gray ramus communicans from sympathetic trunk

where do the roots of the brachial plexus pass through and go into

between anterior and middle scalene muscle into posterior triangle

where is the general location of the roots of the brachial plexus

posterior and superior to subclavian artery

what forms the superior trunk of the brachial plexus

roots of C5 and C6

what forms the middle trunk of the brachial plexus

root of C7

what forms the inferior trunk of the brachial plexus

roots of C8 and T1

where do the trunks of the brachial plexus pass over and go into

over rib 1 and into the axilla

what does each trunk split into

anterior division and posterior division

what will the anterior divisions of the brachial plexus supply

anterior compartment of the arm and forearm

what will the posterior divisions of the brachial plexus supply

posterior compartments of the arm and forearm

how are the brachial plexus cords named

in relationship to axillary artery

what is the lateral cord of the brachial plexus formed from

anterior divisions of the superior and middle trunks

what fibers does the lateral cord contain

C5, C6, and C7

where is the lateral cord of the brachial plexus located

lateral to second part of axillary artery

what is the medial cord of the brachial plexus formed from

anterior division of the inferior trunk

what fibers does the medial cord contain

C8 and T1

where is the medial cord of the brachial plexus located

medial to second part of axillary artery

what is the posterior cord of the brachial plexus formed from

posterior division of superior/middle/inferior trunks

what fibers does the posterior cord contain

C5, C6, C7, C8, and T1

where is the posterior cord of the brachial plexus located

posterior to second part of axillary artery

what nerve does the root of C5 the brachial plexus form

dorsal scapular nerve

what fibers does the dorsal scapular nerve contain

C5 only

what does the dorsal scapular nerve supply

-levator scapula

-rhomboid major

-rhomboid minor

what nerve does the roots of C5, C6, and C7 of the brachial plexus form

long thoracic nerve

what does the long thoracic nerve supply

serratus anterior

what are the nerves formed from roots of the brachial plexus

-dorsal scapular nerve

-long thoracic nerve

what are the nerves branching off the superior trunk of the brachial plexus

-suprascapular nerve

-nerve to the subclavius

what fibers does the suprascapular nerve contain

C5 and C6

what does the suprascapular nerve supply

-supraspinatus

-infraspinatus

what is the only nerve to supply 2 rotator cuff muscles

suprascapular nerve

what fibers does the nerve to the subclavius contain

C5 and C6

what does the nerve to the subclavius supply

subclavius

what are the nerves branching off the lateral cord of the brachial plexus

-lateral pectoral nerve

-musculocutaneous nerve

what fibers does the lateral pectoral nerve contain

C5, C6, and C7

what does the lateral pectoral nerve supply

pectoralis major

what will the pectoralis major also receive innervation from

medial pectoral nerve

what are the 2 terminal branches of the lateral cord of the brachial plexus

-musculocutaneous nerve

-medial nerve

what fibers does the musculocutaneous nerve contain

C5, C6, and C7

what are the muscles the musculocutaneous nerve supply

3 of the 4 muscles of the anterior arm

what does the musculocutaneous nerve supply

-coracobrachialis

-biceps brachii (short + long head)

-brachialis

how does the musculocutaneous nerve interact with the coracobrachialis muscle

pierces through the belly of the muscle

what is formed when the musculocutaneous nerve continues between the biceps brachii and brachialis into the forearm

lateral cutaneous nerve of the forearm

what does the lateral cutaneous nerve of the forearm supply

skin over the lateral aspect of the forearm, not the hand

what are the branches off the medial cord of the brachial plexus

-medial pectoral nerve

-medial cutaneous nerve of the arm

-medial cutaneous nerve of the forearm

-ulnar nerve

-median nerve

what fibers does the medial pectoral nerve contain

C8 and T1

what does the medial pectoral nerve supply

-pectoralis major

-pectoralis minor

what fibers does the medial cutaneous nerve of the arm contain

C8 , T1, and T2

what does the medial cutaneous nerve of the arm supply

skin of the medial arm between the axilla and the elbow

how does the medial cutaneous nerve also receive fibers from T2

through a communication with the intercostobrachial nerve

medial cutaneous arm and forearm nerve supply fibers

-arm = C8 + T1 + T2

-forearm = C8 + T1

what fibers does the medial cutaneous nerve of the forearm contain

C8 and T1

where does the medial cutaneous nerve of the forearm leave the medial cord

just distal to medial cutaneous nerve of the arm

what does the medical cutaneous nerve of the forearm supply

-skin over biceps brachii

-skin over anterior and medial aspect of forearm proximal to the wrist

what are the 2 terminal branches of the medial cord

-ulnar nerve

-medial root of the median nerve

what fibers does the ulnar nerve contain

C8, T1 and sometimes C7

what nerves gives off no branches in the arm

-ulnar nerve

-median nerve

how does the ulnar nerve travel

medial to the brachial artery in the medial bicipital sulcus

where does the ulnar nerve cross

posterior side of the medial epicondyle in the sulcus for the ulnar nerve

what you hit your funny bone what nerve are you hitting

ulnar nerve

the ulnar nerve continues in the forearm and goes between what muscles two heads

flexor carpi ulnaris

what does the ulnar nerve supply

-flexor carpi ulnaris

-medial half of the flexor digitorum profundus

where does the ulnar nerve give off 2 sensory branches

forearm

what are the 2 sensory branches the ulnar nerve gives off

-dorsal branch of the ulnar nerve

-palmar branch of the ulnar nerve

what does the dorsal branch of the ulnar nerve supply

skin over the ulnar side of the posterior hand

what does the palmar branch of the ulnar nerve supply

skin over the hypothenar eminence

where does the ulnar nerve spilt for the second time

deep to flexor carpi ulnaris to the wrist, passing superficial to the flexor retinaculum

what does the ulnar nerve split into when passing superficially to the flexor retinaculum

-superficial ulnar nerve

-deep ulnar nerve

what does the superficial ulnar nerve supply

palmar aspect of the little finger and medial half of the ring finger

what does the deep ulnar nerve supply

-abductor digiti minimi

-flexor digiti minimi brevis

-opponens digiti minimi

-adductor pollicis

-deep head of the flexor pollicis brevis

-all interossei

-lumbricals 3 and 4

what is clinical consideration claw hand

-ulnar nerve damage

-flexion of the dip joints with limited flexion of the pip joints especially digits 4 and 5

what does the median nerve contain contributions from

both lateral and medial cord

what fibers does the median nerve contain

C6, C7, C8 and T1

where does the median nerve travel

through the arm in the medial bicipital sulcus

where does the median nerve cross

elbow on the anterior side and enters the forearm after passing between the two heads of the pronator teres

what muscles does the median nerve pass through both of its heads

pronator teres

what does the median nerve supply

-pronator teres

-flexor carpi radialis

-palmaris longus

-flexor digitorum superficialis

-pronator quadratus, flexor pollicis longus, and the lateral bellies of the flexor digitorum profundus

where is the anterior interosseous nerve of the forearm given off

given off the median nerve in the elbow

where is the palmar branch of the median nerve given off

distal third of the forearm

what does the palmar branch of the median nerve supply

-skin of the thenar eminence

-lateral wrist/palm

where does the median nerve pass through to divide into 3 common palmar digital nerves

carpal tunnel

what nerve passes through the carpal tunnel and divides into 3 common palmar digital nerves

median nerve

what do the 3 common palmar digital nerves supply

first two lumbrical muscles

branches off the first common palmar digital nerve supply what

-abductor pollicis brevis

-flexor pollicis brevis

-opponens pollicis

what does each common palmar digital nerve split into

2 proper palmar digital nerves

what is the function of the proper palmar digital nerves

sensory function only

what do the proper palmar digital nerves supply

skin over the 3.5 digits anteriorly and lateral 2.5 digits posteriorly

what does the median nerve also supply

-periosteum

-elbow, radiocarpal, and midcarpal joints

-communicated with ulnar nerve at the wrist

what is the hand of oath/benediction clinical consideration

-damage is median nerve

-damage to flexor digitorum profundus/superficialis

what is carpal tunnel syndrome

-numbness and tingling of fingers

-median nerve = digits 2-4

-median and ulnar nerve = all fingers

what is the inability to pronate clinical consideration

cant pronate median nerve damaged only