Nerves of Upper Limb

Question 1

Dermatome Sensory Testing Landmarks for C5-T1 in the upper limb

Answer 1

Pattern is preaxial (lateral/radial side)
to postaxial (medial/ulnar side) along limb:
§ C5: shoulder
§ C6: tip of thumb
§ C7: too variable to test
§ C8: tip of fifth digit
§ T1: medial forearm at cubital region

Question 2

Myotomes (action of C5-T1)

Answer 2

o C5: abduction of the shoulder
o C5: flexion of the elbow
o C6: extension of wrist
o C7: flexion of wrist, extension of fingers
o C7–C8: extension of the elbow
o C8: flexion of fingers
o T1: abduction/adduction of fingers

Question 3

Reflex testing: where on the body (what muscles/reflexes) do you test C5, C6, and C7?

Answer 3

C5: biceps reflex
C6: brachioradialis reflex
C7: triceps reflex

Question 4

Dorsal Scapular Nerve

Answer 4

C5 (branch of C5 root from brachial plexus)

Question 5

Long Thoracic Nerve

Answer 5

C5, C6, C7 (from roots of these nerves in brachial plexus)

Question 6

Suprascapular Nerve

Answer 6

C6, C6 (branch from superior trunk of brachial plexus)

Runs thru suprascapular foramen (w/ suprascapular artery) and UNDER superior transverse scapular ligament

Question 7

Nerve to Subclavius

Answer 7

C5, C6 (branch from superior trunk of brachial plexus)

Question 8

Lateral Pectoral Nerve

Answer 8

C5, C6, C7 (branch of lateral cord from brachial plexus)

Found along the medial border of pec minor

Question 9

Upper Subscapular Nerve

Answer 9

C5, C6 (branch of posterior cord [C5-8] from brachial plexus)

Question 10

Lower Subscapular Nerve

Answer 10

C5, C6 (branch of posterior cord [C5-8] from brachial plexus)

Question 11

Thoracodorsal Nerve

Answer 11

C6, C7, C8 (branch of posterior cord [C5-8] from brachial plexus)

Question 12

Medial Pectoral Nerve

Answer 12

C8, T1 (branch of medial cord [C8-T1] from brachial plexus)

Question 13

Medial Brachial Cutaneous Nerve

Answer 13

C8, T1 (branch of medial cord [C8-T1] from brachial plexus)

Question 14

Medial Antebrachial Cutaneous Nerve

Answer 14

C8, T1 (branch of medial cord [C8-T1] from brachial plexus)

Question 15

Axillary Nerve

Answer 15

C5, C6 (Terminal branch from posterior cord [C5-8] of brachial plexus)
Motor to deltoid & teres minor, cutaneous to lateral arm
Found in quadrangular space

Question 16

Radial Nerve

Answer 16

C5, C6, C7, C8 (Terminal branch from posterior cord [C5-8] of brachial plexus)
Motor to posterior arm/forearm, 1/2 brachialis, cutaneous to dorsolateral hand & posterior forearm

Question 17

Musculocutaneous Nerve

Answer 17

C5, C6, C7 (Terminal branch from lateral cord [C5-7] of brachial plexus)
Motor to anterior arm, cutaneous to lateral forearm via lateral antebrachial cutaneous nerve

Question 18

Median Nerve

Answer 18

C6, C7, C8, T1 (Terminal branch formed from contributions of lateral and medial cords)
Motor to anterior forearm (except fl. carpi ulnaris & 1/2 fl. dig. profundus), thenar muscles, lateral 2 lumbricles, cutaneous to lateral palm, lat 3.5 digits, including dorsal fingertips

Question 19

Ulnar Nerve

Answer 19

C8-T1 (Terminal branch of medial cord [C8-T1] from brachial plexus)
Motor to fl. carpi ulnaris & 1/2 fl. dig. profundus, all intrinsic hand muscles (except thenar muscles, lat 2 lumbricles) cutaneous to medial palm, medial 1.5 digits