Brachial Plexus Lesions

Question 1

What does the musculocutaneous nerve innervate?

Answer 1

Biceps brachii
Brachialis
Coracobrachialis

Question 2

If there’s damage to the musculocutaneous nerve, what’s affected?

Answer 2

• weakened adduction, flexion, and supination
• Loss of flexion at elbow
• Diminished cutaneous sensation to anterolateral skin of forearm

Question 3

What does the axillary nerve innervate?

Answer 3

Deltoid and teres minor

Question 4

If there’s damage to the axillary nerve, what’s affected?

Answer 4

• Weakened ability to abduct arm, lateral rotation, medial rotation, extension, and flexion
• Diminished cutaneous sensation to skin covering deltoid

Question 5

An affected radial nerve has affected extensor muscles of the

Answer 5

Shoulder, elbow, wrist and digits

Question 6

In the radial nerve, if there’s injury in the axilla, what’s affected?

Answer 6

• Weakened extension at shoulder
• Loss of extension at elbow

Question 7

In the radial nerve, if there’s injury at the elbow joint, what’s affected?

Answer 7

• Weakened supination
• Loss of extension of hand at wrist
• Loss of extension of digits

Question 8

Does the median nerve innervate above the elbow?

Answer 8

No

Question 9

If there’s injury at elbow or above the median nerve, what’s affected?

Answer 9

Loss of pronation
Weakened flexion at wrist

Question 10

If there’s injury at wrist, that involves the median nerve, what’s affected?

Answer 10

Diminished/loss of ability to appose the thumb
Loss of flexion of thumb, index, or middle fingers

Question 11

In the median nerve, there’s diminished cutaneous sensation to digits ___ and lateral ___ of digit ___ and lateral palmar surface of hand

Answer 11

1-3
1/2
4

Question 12

Carpal tunnel syndrome is cause by the ___ nerve

Answer 12

Median

Question 13

If there’s injury at elbow or above, in the ulnar nerve, what’s affected?

Answer 13

weakened flexion at wrist
Loss of flexion of 4-5 digits

Question 14

If there’s injury at wrist in ulnar nerve, what’s affected?

Answer 14

Most small intrinsic muscles of hand

Question 15

Loss of cutaneous sensation in the ulnar nerve affected digit ___ and medial ___ of digit ___

Answer 15

5
1/2
4

Question 16

Label the anterior brachium and antebrachium terminal branches of the brachial plexus

Answer 16

Question 17

Label the posterior brachium and antebrachium terminal branches of the brachial plexus

Answer 17

Question 18

Label the palmar terminal branches of the brachial plexus

Answer 18

Question 19

Do ulnar and median nerves innervate structures of the shoulder or arm?

Answer 19

No

Question 20

Define lesions

Answer 20

injury that affects the function of the nerves in the body

Question 21

Structures ___ to the site of the lesion are affected while those structures ___ to the lesion are not affected

Answer 21

Distal
Proximal

Question 22

Injuries to the neck or shoulder can often lead to injuries to ___

Answer 22

brachial plexus structures

Question 23

An upper trunk injury mostly affects what nerves?

Answer 23

Suprascapular, axillary and musculocutaneous nerve

Question 24

Upper trunk injury is caused by

Answer 24

separation of head and shoulder during birth or injury

Question 25

A lower trunk injury affects which nerve?

Answer 25

Ulnar nerve

Question 26

Lower trunk injury is caused by

Answer 26

Arm pulled upward during birth or injury

Question 27

A long thoracic nerve injury results in ___ scapular

Answer 27

Winged scapula