Radial nerve

Question 1

Course of radial nerve

Answer 1

Continuation of posterior cord and exits axilla posterior to brachial artery
Descends down arm in radial groove of humerus, accompanied by deep artery of arm
Moves anteriorly over lateral epicondyle through cubital fossa

Question 2

Termination of radial nerve

Answer 2

Within forearm it divides into:

Deep branch
Superficial branch

Question 3

Where do the branches arise that innervate long and medial heads of triceps brachii

Answer 3

Where it exits axilla

Posterior to brachial artery

Question 4

Where does the branch arise that innervates the lateral head of triceps brachii

Answer 4

Where the radial nerve wraps laterally around the humerus

Question 5

Function of radial nerve

Answer 5

Motor Innervation to triceps brachii

Question 6

Function of deep branch

Answer 6

Motor Innervation of posterior forearm

Question 7

What are the 4 sensory branches of the radial nerve

Answer 7

Lower lateral cutaneous nerve of arm
Posterior cutaneous nerve of arm
Posterior cutaneous nerve of forearm
Superficial branch

Question 8

Function of lower lateral cutaneous nerve of arm

Answer 8

Sensory Innervation to lateral arm below deltoid

Question 9

Function of posterior cutaneous nerve of arm

Answer 9

Sensory Innervation to posterior arm

Question 10

Function of posterior cutaneous nerve of forearm

Answer 10

Sensory Innervation to strip of skin down middle of posterior forearm

Question 11

Function of superficial branch of radial nerve

Answer 11

Sensory Innervation to dorsal surface of lateral 3 and 1/2 fingers (except fingertips = median) and associated dorsal area

Question 12

How is the radial nerve damaged in the axilla

Answer 12

Dislocation of shoulder,
Proximal humerus fractures,
Excessive pressure on axilla

Question 13

Consequence of damage in axilla

Answer 13

Paralysis of triceps brachii and posterior forearm
Wrist drop
Loss of sensation over:
Lateral and posterior arm
Posterior forearm
Dorsal surface of lateral 3 and 1/2 fingers and associated dorsal area

Question 14

How does damage to radial nerve occur in radial groove

Answer 14

Fracture of shaft of humerus

Question 15

Consequence of damage in radial groove

Answer 15

Triceps brachii weakened
Paralysis of posterior forearm
Wrist drop
Loss of sensation over dorsal surface of lateral 3 and 1/2 fingers and associated dorsal area

Question 16

How does damage to deep branch occur

Answer 16

Fracture of radial head

Posterior dislocation of radius at elbow

Question 17

Consequence of damage to deep branch

Answer 17

Paralysis of posterior forearm except supinator and extensor carpi radialis longus
No wrist drop (extensor carpi radialis longus is a strong wrist extensor)
No sensory loss

Question 18

How does damage to superficial branch occur

Answer 18

Stabbing or laceration of forearm

Question 19

Consequence of damage to superficial branch

Answer 19

Loss of sensation over dorsal surface of lateral 3 and 1/2 fingers and associated dorsal area

Question 20

Spinal roots

Answer 20

C5-T1