Nerves

Question 1

Musculocutaneous nerve arises from which roots

Answer 1

C5-C7

Question 2

Motor innervation of musculocutaneous

Answer 2

All muscles of the anterior compartment of arm. Biceps brachi, coracobrachialis, brachialis.

Question 3

Note: all the nuscless in the anterior compartment of arm are flexors

Answer 3

..

Question 4

Sensory innervation of musculocutaneous nerve

Answer 4

Lateral cutaneous nerve of forearm

Provides innervvation to the lateral aspect of the forearm

Question 5

Lesion of musculocutaneous nerve causes what?

Answer 5

Loss of sensation at the lateral aspect of forearm

Weakness of elbow flexion and forearm supination

Question 6

Motor innervation of axillary nerve

Answer 6

Deltoid and teres minor

Question 7

Sensory innervation is of axillary nerve

Answer 7

Superiolateral aspect of arm

Question 8

Course of axillary nerve

Answer 8

Passes through the quadrangular space with the posterior circumflex humeral artery

Question 9

How is It injured..axillary nerve

Answer 9

Fracture of the axillary neck of the humerus

Question 10

What roots does the axillary nerve arise from

Answer 10

5, 6

Question 11

Sensory branch if axillary nerve?

Answer 11

Superior lateral brachial cutaneous nerve

Question 12

What are the roots of the radial nerve

Answer 12

C5-T1

Question 13

Motor innervation of radial nerve

Answer 13

All extensor muscles of arm and forearm

Question 14

Which muscles are supplied by the radial nerve in the arm

Answer 14

Triceps brachi

Question 15

What does the radial nerve innervate in the forearm

Answer 15

10 extensors, 5 of which originate from lateral epicondyle(common extensor tendon)

Question 16

Which of the 5 extenders originate from the lateral epicondyle

Answer 16

Extensor carpi radialis brevis
Extensor digitorium
Extensor digit minimizes 
Extensor carpi ulnaris
Anconeus

Question 17

Sensory innervation of radial nerve

Answer 17

Posterior aspect of arm and forearm

Question 18

Lesions of the radial nerve injuries?

Answer 18

Mid shaft injuries of the humerus

Pressure of badly crutches

Question 19

Lesion of the radial nerve results in

Answer 19

Wrist drop (Saturday night palsy or honeymoon palsy)

Due to the fact that wrist and fingers cannot extend at metacarpophalangeal joints. Extensors paralyzed due to denervation. Wrist remains partially flexed due to opposing action of flexors in forearm

Brachioradialis and supinator paralysed

Question 20

Sensory innervation and damage of radial nerve

Answer 20

Posterior surface of lower arm, lateral dorsum of hand, dorsal surface of roots of lateral 3 and 1/2 fingers