Part 10: Summary of UL Innervation

Question 1

Describe the cutaneous innervation of the shoulder and axilla

Answer 1

Shoulder: C4 - fromt the cervical plexus, continuation of neck innervation
Axilla: lateral branch of 2nd intercostal nerve

Question 2

Describe the cutaneous innervation of the arm

Answer 2

Posterior: Post cutaneous nerve of arm (radial)
Lateral: upper lateral cut n of arm (axillary) and lower lateral cut n of arm (radial)
Medial: medialcut n of arm (medial cord BP)

Question 3

Describe the cutaneous innervation of the forearm

Answer 3

Medial: Medial cut n of forearm (medial cord BP)
Lateral: Lat cut nerve of forearm (radial)
Posterior: post cut nerve of forearm (radial)

Question 4

Describe the cutaneous innervation of the palm

Answer 4

Ulnar side: superficial branch of ulnar nerve
Middle: palmar branch of median n
Digits: digital nerves from palmar branches of U+M nerves (M3.5/U1.5)

Question 5

Describe the cutaneous innervation of the dorsal surface of the hand

Answer 5

Ulnar side: 1.5 digits supplied by dorsal branch of ulnar nerve
Radial side: 3.5 digits supplied by terminal cut branches of radial nerve

Note: usually more 2.5/2.5 than 1.5/3.5

Question 6

The muscles of the flexor compartment of the arm are supplied by which nerves?

Answer 6

Musculocutaneous nerve

Question 7

The muscles of the extensor compartment of the arm arm supplied by which nerves?

Answer 7

Radial nerve

Question 8

The muscles of the flexor compartment of the forearm are supplied by which nerves?

Answer 8

Median nerve supplies all but FCU and ulnar half of FDP

Question 9

The muscles of the extensor compartment of the forearm are supplied by which nerves?

Answer 9

Radial nerve - mostly by it posterior interosseous branch

Question 10

Describe the sympathetic innervation of the UL

Answer 10

Grey ramus communicantes join each root in BP. They remain in the nerves (hitchhike) until very near distination of their supply. Thus they sympathetic innervation is the same as dermatomes