Brachial Plexus

Question 1

What nerve roots makes up the Median nerve?

Answer 1

C5, 6, 7, 8 and T1

Question 2

What makes up the superior trunk?

Answer 2

Nerve roots C5 and 6

Question 3

What makes up the middle trunk?

Answer 3

nerve root C 7

Question 4

What makes up the inferior trunk?

Answer 4

C8 and T1

Question 5

what trunks makes up the lateral cord? and therefore what roots?

Answer 5

anterior divisions of the superior and middle trunk - C5, 6 and 7

Question 6

What trunks makes up the posterior cord? and therefore what roots?

Answer 6

posterior divisions of the superior, middle and inferior trunks - C5-T1

Question 7

What trunks makes up the medial cord? and therefore what roots?

Answer 7

anterior division of the inferior trunk - C8 and T1

Question 8

what gives rise to the axillary nerve?

Answer 8

posterior cord - superior trunk - C5 and 6

Question 9

what gives rise to the musculocutaneous nerve?

Answer 9

Lateral cord - superior+middle trunk - C5, 6 and 7

Question 10

what gives rise to the median nerve?

Answer 10

lateral and medial cords - superior middle and inferior trunks - C6-T1

Question 11

What makes up the radial nerve?

Answer 11

posterior cord - superior, middle and inferior trunk- C5-T1

Question 12

Damage to what nerve would cause winging of the scapula?

Answer 12

Long thoracic nerve (usually)

Could be accessory or dorsal scaupla nerve

Question 13

What are the roots of the long thoracic nerve?

Answer 13

5 6 7 - wings to heaven - damage to this nerve causes winging of the scapula.

Question 14

What gives rise to the ulnar nerve

Answer 14

medial cord - inferior trunk - C8 and T1

Question 15

What muscles flex the arm? what nerve innervates them?

Answer 15

-Musculocutaneous

BBC: -biceps brachii -brachialis -coracobrachialis

Question 16

What is the sensory supply of the musculocutaneous nerve?

Answer 16

lateral forearm

Question 17

What muscles abduct the arm? and what nerve innervates them?

Answer 17

Deltoid - innervated by the Axillary nerve (P,S,5+6)

supraspinatus - innervatred by the suprascapular

Question 18

What is the sensory innervation of the axillary nerve?

Answer 18

Inferior portion of the deltoid - regimental badge

Question 19

What forearm muscles does the median nerve innervate?

Answer 19

• 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

Question 20

What hand muscles does the median nerve innervate?

Answer 20

L-LOAF

2 lateral lumbricals

oppens pollicus

flexor pollicus brevis

abductor pollicus brevis

Question 21

What are the thenar muscles?

Answer 21

• oppens pollicus
• abductor pollicus brevis
• flexor pollicus brevis
• adductor pollicus

Question 22

What movements does the median nerve control?

Answer 22

forearm pronation

wrist felxion

wrist abduction

thumb movements

lateral DIP joint felxion

Question 23

What is the sensory innervation of the median nerve?

Answer 23

M shape

lateral palm - index, middle and half of ring fingers

only tips on the posterior

Question 24

What happens in a lesion of the median nerve at the elbow?

Answer 24

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

Question 25

What happens in a lesion of the median nerve at the wrist?

Answer 25

thenar muscles + lateral 2 lumbricals paralysed (sign of benediction) forearm not affected (can pronate and flex wrist) sensory loss to the M + palm

Question 26

What compartment of the arm does the radial nerve innervate?

Answer 26

posterior compartment of the arm posterior compartment of the forearm

Question 27

Myotomes C5 - T1

Answer 27

C5 - elbow flexion C6 - wrist extension C7 - elbow extension C8 - finger flexion T1 - finger abduction

Question 28

dermatomes C5 - T2

Answer 28

C5 - over deltoid C6 - forearm to thumb C7 - index + middle C8 - little + ring fingers T1 - inner arm T2 - apex of the axilla

Question 29

What is the sensory innervation of the raidal nerve?

Answer 29

posterior arm posterior forearm dorsal 3.5 lateral digits + back of hand

Question 30

What muscles does the radial nerve supply?

Answer 30

- 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

Question 31

What happen in damage to the radial nerve in the axilla?

Answer 31

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

Question 32

What would cause damage to the radial nerve in the axilla?

Answer 32

poorly fitted crutches shoulder dislocation

Question 33

What happens in damage to the radial nerve at the radial groove?

Answer 33

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

Question 34

What would cause damage to the radial nerve at the level of the radial groove?

Answer 34

humeral shaft fracture

Question 35

What would happen in a lesion to the superficial branch of the radial nerve in the forearm? How could this occur?

Answer 35

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

Question 36

What would happen in a lesion affecting the deep branch of the radial nerve in the forearm? How could this happen?

Answer 36

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

Question 37

What muscles does the ulnar nerve innervate?

Answer 37

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

Question 38

What roots make up the ulnar nerve?

Answer 38

C8 & T1

Question 39

Describe what happens in damage to the ulnar nerve at the elbow.

Answer 39

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!

Question 40

Describe what happen in damage to the ulnar nerve at the wrist?

Answer 40

- just intrinsic hand muscle affected - add+abduction of the fingers - little and ring finger movement impairment - Hypothenar wasting! - palmar sensation lost, dorsal usually retained