Cutaneous Innervation and Myotome/Dermatome Testing

Question 1

Cutaneous off of Axillary

Answer 1

Superior lateral cutaneous nerve of arm

C5-C6

Question 2

Cutaneous off of Radial

Answer 2

Inferior lateral brachial cutaneous nerve (5-6)
Posterior brachial cutaneous nerve (5-8)
Posterior antebrachial cutaneous nerve (5-8)
Superficial branch of radial nerve - dorsum and lateral thenar area of hand (6-8)

Question 3

Cutaneous off of musculocutaneous

Answer 3

Lateral antebrachial cutaneous nerve (6-7)

Question 4

Cutaneous off of median nerve

Answer 4

Cutaneous branch of median nerve - palmar surface of lateral three digits and fingertips, lateral palm (6-8)

Question 5

Cutaneous off of ulnar nerve

Answer 5

Dorsal branch of ulnar nerve - palmar and dorsal surface of medial hand and medial two digits (8-1)

Question 6

Myotomes follow what pattern

Answer 6

proximal to distal along the limb

Question 7

C5 myotome

Answer 7

abduction of shoulder

Question 8

C6-C7 myotome

Answer 8

extension of the wrist (C6)

extension of the fingers (C7)

Question 9

C7-T1 myotome

Answer 9

flexion of the wrist (C7)
flexion of the fingers (C8)
abduction/adduction of fingers (T1)

Question 10

C5 - reflex

Answer 10

biceps reflex

Question 11

C6 - reflex

Answer 11

brachioradialis reflex

Question 12

C7 - reflex

Answer 12

triceps reflex

Question 13

Sequence for dermatome mapping

Answer 13

pre-axial to post-axial along the limb

lateral to medial

Question 14

C5 dermatome testing

Answer 14

shoulder

Question 15

C6 dermatome testing

Answer 15

thenar eminence

Question 16

C7 dermatome testing

Answer 16

too variable to test

Question 17

C8 dermatome testing

Answer 17

hypothenar eminence

Question 18

T1 dermatome testing

Answer 18

medial forearm at cubital region

Question 19

T2 dermatome testing

Answer 19

axilla

Question 20

Testing for function of peripheral nerves - axillary

Answer 20

lateral aspect of deltoid

Question 21

Testing for function of peripheral nerves - musculocutaneous

Answer 21

lateral forearm

Question 22

Testing for function of peripheral nerves - radial

Answer 22

dorsum of webbing btw thumb and index finger

Question 23

Testing for function of peripheral nerves - median

Answer 23

tip of index finger

Question 24

Testing for function of peripheral nerves - ulnar

Answer 24

medial tip of pinky