Musculocutaneous Nerve

Question 1

What are the nerve roots of musculocutaneous nerve

Answer 1

C5-7

Question 2

What are the motor functions of musculocutaneous nerve

Answer 2

Anterior compartment of arm (coracobrachialis, biceps brachii, brachialis)

Question 3

What are the sensory functions of musculocutaneous

Answer 3

Gives rise to lateral cutaneous nerve of forearm:-

Innervates skin on lateral surface of forearm

Question 4

What is the path of musculocutaneous nerve after originating from brachial plexus

Answer 4

Leaves axilla
Pierces corachobrachialis near its point of insertion on humerus
Passes down arm anterior to brachialis but deep to biceps
Emerges laterally to biceps tendon and continues into forearm as lateral cutaneous nerve

Question 5

What do the muscles of the anterior compartment of the arm do

Answer 5

Flex upper arm at shoulder and elbow

Question 6

What is the course of lateral cutaneous nerve of forearm

Answer 6

Initially enters deep forearm
Pierces deep fascia to become subcutaneous
Found in close proximity to cephalic vein

Question 7

What is the most common cause of damage to musculocutaneous nerve

Answer 7

Stab wound to axilla

Question 8

What are the motor implications of musculocutaneous nerve damage

Answer 8

Muscles of anterior compartment of arm paralysed
Flexion at shoulder weakened
Flexion at elbow weakened
Supination greatly weakened

Question 9

What are the sensory implications of musculocutaneous nerve damage

Answer 9

Loss of sensation over lateral side of forearm