Anatomy Ii -- Upper Limb Innervation

Front 1

What nerve roots contribute to the brachial plexus?

Back 1

C5, C6, C7, C8, T1

Front 2

Which division sends fibers to nerves innervating flexor muscles?

Back 2

Anterior

Front 3

What nerve roots contribute to the musculocutaneous nerve?

Back 3

C5, C6, (C7)

Front 4

What division of the upper limb does the musculocutaneous nerve innervate?

Back 4

Anterior arm

Front 5

What muscles does the musculocutaneous nerve innervate?

Back 5

Biceps brachii
Brachialis
Coracobrachialis

Front 6

What innervates the biceps brachii?

Back 6

Musculocutaneous nerve

Front 7

What innervates the coracobrachialis?

Back 7

Musculocutaneous nerve

Front 8

What nerve roots contribute to the median nerve?

Back 8

(C5), C6, C7, C8, T1

Front 9

What division of the upper limb does the median nerve innervate?

Back 9

Anterior forearm (plus some intrinsic hand muscles)

Front 10

What is the cutaneous region innervated by the musculocutaneous nerve?

Back 10

Lateral side of forearm

Front 11

What muscles does the median nerve innervate?

Back 11

All anterior forearm muscles (except 1 1/2)
Thenar muscles
2 lumbricals in hand

Front 12

What is the most commonly lesioned nerve in the upper limb, and where is it lesioned?

Back 12

Median nerve
In carpal tunnel

Front 13

What is the cutaneous region innervated by the median nerve?

Back 13

Lateral half of palm of hand; lateral 3 1/2 digits (palmar side continuing through tips to nailbeds)

Front 14

What nerve roots contribute to the ulnar nerve?

Back 14

C8, T1

Front 15

What compartments of the upper arm does the ulnar nerve innervate?

Back 15

Some in anterior forearm; all intrinsic hand muscles (except thenar and 2 lumbricals by median nerve)

Front 16

What is the cutaneous region innervated by the ulnar nerve?

Back 16

median third of palm, ulnar 2.5 digits on the dorsal side, and 1.5 digits on the palmar side of the hand

Front 17

What nerve roots contribute to the axillary nerve?

Back 17

C5, C6

Front 18

What muscles are innervated by the axillary nerve?

Back 18

Teres minor and deltoid

Front 19

What nerve roots contribute to the radial nerve?

Back 19

C5, C6, C7, C8, (T1)

Front 20

What compartments of the upper limb are innervated by the radial nerve?

Back 20

posterior arm and posterior forearm

Front 21

What muscles are innervated by the radial nerve?

Back 21

Triceps and all posterior forearm muscles

Front 22

What is the cutaneous region innervated by the radial nerve?

Back 22

parts of posterior arm and forearm; dorsum of lateral 2.5 digits and hand

Front 23

Lesion of what nerve can cause weakness in abduction at shoulder? What muscle is affected?

Back 23

Axillary nerve, affecting deltoid muscle

Front 24

Lesion of what nerve can cause wrist drop? What other physical signs are present?

Back 24

Radial nerve; also affects thumb abduction and extension and supination of forearm

Front 25

Lesion of what nerve causes weakness in opposition of thumb?

Back 25

Median nerve (distal lesion)

Front 26

Lesion of what nerve can cause the "hand of benediction"? What could be the cause of this lesion?

Back 26

Median nerve; compression between the heads of pronator teres

Front 27

What could cause a distal lesion of the ulnar nerve?

Back 27

Fracture of the hook of hamate

Front 28

Lesion of what nerve would cause weakness with pronation?

Back 28

Median nerve

Front 29

What nerve would be damaged with an upper trunk compression?

Back 29

Musculocutaneous

Front 30

What could cause a lower trunk compression?

Back 30

Presence of cervical rib;
Apical lung neoplasm

Front 31

What could cause all fingers to be clawed? (simian hand)

Back 31

Lower trunk compression -- combined median and ulnar nerve lesions

Front 32

What is Erb-Duchenne palsy?

Back 32

avulsion of the C5 and C6 roots of the brachial plexus