nerve innervations of the upper limb

Question 1

what is the muscle supply of the axillary nerve

Answer 1

the deltoid and the teres minor

Question 2

what is the path the axillary nerve takes in the upper limb

Answer 2

it comes from the posterior cord of the brachial plexus, going inferior to the subscapularis and then going behind and around the surgical neck of the humerus. it then innervates the deltoid and the teres minor. also innervates the upper lateral cutaneous area of the arm

Question 3

cutaneous innervation of the axillary nerve

Answer 3

the upper lateral area of the arm, so essentially the deltoid muscle region of skin

Question 4

what muscles does the radial nerve innervate

Answer 4

the posterior arm - so triceps
the supinator muscle and the posterior forearm - the posterior interosseous nerve

Question 5

whats the cutaneous innervations of the radial nerve

Answer 5

the posterior arm and forearm areas, and the dorsal hand with the radial 3.5 fingers but not the nail beds

Question 6

whats the path the radial nerve takes in the upper limb

Answer 6

from the posterior cord it goes to the posterior compartment of the upper limb to supply the triceps brachii. it then travels through the radial groove with the deep brachial artery and vein to in front of the lateral epicondyle.
from here it splits into the deep and superficial branches. deep does the posterior arm innervation. the superficial branch travels travels to the hand to do the radial 3.5 fingers and dorsal hand surface

Question 7

what is the muscle innervation of the musculocutaneous nerve

Answer 7

it supplies the anterior arm

Question 8

whats the cutaneous innervation of the musculocutaneous nerve

Answer 8

it becomes the lateral cutaneous nerve of the forearm, so it does the lateral forearm

Question 9

whats the path taken by the musculocutaneous nerve

Answer 9

comes from the lateral cord of the brachial plexus, going into the arm and innervating all the muscles in the anterior arm compartment.
then travels to the forearm and supplies the lateral skin of the forearm

Question 10

whats the muscle innervation of the ulnar nerve

Answer 10

forearm supplies the flexor carpi ulnaris and the medial HALF of the flexor digitorum profundus
in the hand it does:
the hypothenar muscles, the adductor pollicis, the interossei muscles and the medial two lumbricals

Question 11

whats the cutaneous innervation of the ulnar nerve

Answer 11

the skin of the medial one and a half fingers on the palmar and dorsal aspects of the hand.

Question 12

what are the two structures the ulnar nerve travels through and where do we find these structures?

Answer 12

passing behind the medial epicondyle the ulnar nerve travels through the Cubital tunnel
going into the hand the ulnar nerve travels in the gyons canal

Question 12

whats the pathway of the ulnar nerve in the upper limb

Answer 12

comes from the medial cord and runs down the arm going behind the medial epicondyle - running through the cubital tunnel.
in the forearm it supplies the flexor carpi ulnaris and the medial half of the flexor digitorum profundus. then it continues to the hand, travelling through the gyons canal to then innervate all of the hypothenar muscles, the adductor pollicis muscle the interossei and the medial 2 lumbricals.
It also gives cutaneous sensation supply to the skin of the medial one and a half fingers on the palmar and dorsal aspects.

Question 12

whats the motor supply of the median nerve

Answer 12

it supplies all the anterior forearm muscles except for the flexor carpi ulnaris and the medial half of the flexor digitorum profundus.
in the hand it supplies the thenar muscles and the lateral 2 lumbricals

Question 13

whats the cutaneous supply of the median nerve

Answer 13

palmar side of the hand, being the radial 3.5 fingers and the dorsal nail beds that the radial nerve does not supply.

Question 14

describe the path of the median nerve

Answer 14

coming from the lateral and medial cords it travels through the arm without giving off any innervation. it then enters the forearm where it supplies all anterior forearm muscles except the medial FDP and the FCU - as that’s ulnar nerve.
it then goes into the hand through the carpal tunnel to supply the thenar muscles, and the lateral two lumbircals.
there is also a palmar branch of this muscle which goes to the palmar side skin of the radial 3 and a half fingers and the dorsal side of the distal 3.5 phalanges - where the radial nerve doesn’t go.