What nerve roots makes up the Median nerve?
C5, 6, 7, 8 and T1
What makes up the superior trunk?
Nerve roots C5 and 6
What makes up the middle trunk?
nerve root C 7
What makes up the inferior trunk?
C8 and T1
what trunks makes up the lateral cord? and therefore what roots?
anterior divisions of the superior and middle trunk - C5, 6 and 7
What trunks makes up the posterior cord? and therefore what roots?
posterior divisions of the superior, middle and inferior trunks - C5-T1
What trunks makes up the medial cord? and therefore what roots?
anterior division of the inferior trunk - C8 and T1
what gives rise to the axillary nerve?
posterior cord - superior trunk - C5 and 6
what gives rise to the musculocutaneous nerve?
Lateral cord - superior+middle trunk - C5, 6 and 7
what gives rise to the median nerve?
lateral and medial cords - superior middle and inferior trunks - C6-T1
What makes up the radial nerve?
posterior cord - superior, middle and inferior trunk- C5-T1
Damage to what nerve would cause winging of the scapula?
Long thoracic nerve (usually)
Could be accessory or dorsal scaupla nerve
What are the roots of the long thoracic nerve?
5 6 7 - wings to heaven - damage to this nerve causes winging of the scapula.
What gives rise to the ulnar nerve
medial cord - inferior trunk - C8 and T1
What muscles flex the arm? what nerve innervates them?
-Musculocutaneous
BBC: -biceps brachii -brachialis -coracobrachialis
What is the sensory supply of the musculocutaneous nerve?
lateral forearm
What muscles abduct the arm? and what nerve innervates them?
Deltoid - innervated by the Axillary nerve (P,S,5+6)
supraspinatus - innervatred by the suprascapular
What is the sensory innervation of the axillary nerve?
Inferior portion of the deltoid - regimental badge
What forearm muscles does the median nerve innervate?
- pronator teres - pronation
- pronator quadratus -pronation
- flexor carpis radialis - flexes wrist
- felxor policus longus - thumb felxion
- flexor digitorum superficialis - finger flexion
- lateral 1/2 flexor digitorum profundus - finger flexion
What hand muscles does the median nerve innervate?
L-LOAF
2 lateral lumbricals
oppens pollicus
flexor pollicus brevis
abductor pollicus brevis
What are the thenar muscles?
- oppens pollicus
- abductor pollicus brevis
- flexor pollicus brevis
- adductor pollicus
What movements does the median nerve control?
forearm pronation
wrist felxion
wrist abduction
thumb movements
lateral DIP joint felxion
What is the sensory innervation of the median nerve?
M shape
lateral palm - index, middle and half of ring fingers
only tips on the posterior
What happens in a lesion of the median nerve at the elbow?
wrist flexion weak + adduction
loss of sensation to the M palm
supination constantly (loss of pronation)
can’t flex index + middle finger (benediction sign)
thenar atrophy + loss of thumb opposition
What happens in a lesion of the median nerve at the wrist?
thenar muscles + lateral 2 lumbricals paralysed (sign of benediction)
forearm not affected (can pronate and flex wrist)
sensory loss to the M + palm
What compartment of the arm does the radial nerve innervate?
posterior compartment of the arm
posterior compartment of the forearm
Myotomes C5 - T1
C5 - elbow flexion
C6 - wrist extension
C7 - elbow extension
C8 - finger flexion
T1 - finger abduction
dermatomes C5 - T2
C5 - over deltoid
C6 - forearm to thumb
C7 - index + middle
C8 - little + ring fingers
T1 - inner arm
T2 - apex of the axilla
What is the sensory innervation of the raidal nerve?
posterior arm
posterior forearm
dorsal 3.5 lateral digits + back of hand
What muscles does the radial nerve supply?
- 3 wirst extensors - Extensor carpi radialis B+L, ulnaris
- 2 finger extensors - extensor digitorum + digiti minimi
- 2 thumb things - extensor pollicus longus + abductor pollicus longus
- 2 other - TRICEPS + supinator
What happen in damage to the radial nerve in the axilla?
all muscles affected
triceps, wrist and finger extensors
causing wrist drop
loss of sensation at lateral and posterior arm, posterior forearm and dorsum of the hand
What would cause damage to the radial nerve in the axilla?
poorly fitted crutches
shoulder dislocation
What happens in damage to the radial nerve at the radial groove?
triceps weakened but not paralysed
posterior forearm affected - unable to extend wrist and fingers
Just sensory lost to the dorsum of the hand as cuteneous nerve have already arisen
What would cause damage to the radial nerve at the level of the radial groove?
humeral shaft fracture
What would happen in a lesion to the superficial branch of the radial nerve in the forearm? How could this occur?
loss of sensation to the dorsum of the lateral 3 and a half digits and associated dorsal hand area
stabbinng of laceration
NO MOTOR FUNCTION LOST
What would happen in a lesion affecting the deep branch of the radial nerve in the forearm? How could this happen?
posterior forearm muscles affected but wrist drop does not occur because still some innervation to extensor carpi radialis longus
posterior dislocation of the radius or fracture of the radial head
NO SENSORY LOSS
What muscles does the ulnar nerve innervate?
couple in the anterior forearm:
- felxor carpi ulnaris
- ulnar half of flexor digitorum profundus
lots in the hand:
- medial lumbricals
- palmer and dorsal interossi
- adductor pollicus
- hypothenar emminece
- palmaris brevis
What roots make up the ulnar nerve?
C8 & T1
Describe what happens in damage to the ulnar nerve at the elbow.
movements of ring and little fingers impaired (medial lumbricals + hypothenar shit)
finger add + abduction impaired (interossi)
impairment of thumb adduction (canny grip paper with thumb + index)
sensory loss to the palmar and dorsal 4th amd 5th digits
Hypothenar wasting!
Describe what happen in damage to the ulnar nerve at the wrist?
- just intrinsic hand muscle affected
- add+abduction of the fingers
- little and ring finger movement impairment
- Hypothenar wasting!
- palmar sensation lost, dorsal usually retained