Brachial Plexus Anatomy

Question 1

What does the long thoracic nerve innervate

Answer 1

Serratus anterior

Question 2

NCS findings in plexopathy that distinguishes injury proximal vs distal to DRG

Answer 2

Proximal - SNAP is preserved, but CMAP is abnormal

Distal - decreased SNAP

Question 3

What muscles does musculocutaneous nerve innervate

Answer 3

Brachialis, biceps, coracobrachialis

Question 4

What nerves come off the medial cord?

Answer 4

Medial brachial and antebrachial cutaneous nerves

Question 5

What makes up the musculocutaneous branch?

Answer 5

Lateral cord

Question 6

What does the upper subscapular nerve innervate

Answer 6

Subscapularis

Question 7

Where does suprascapular nerve branch from

Answer 7

Upper trunk

Question 8

Nerve root innervation for subscapularis

Answer 8

C5,6,7

Question 9

What is nerve root innervation for pectoralis minor

Answer 9

C8,T1

Question 10

What does the medial pectoral nerve innervate

Answer 10

Pectoralis major and pectoralis minor

Question 11

What makes up the medial cord of the brachial plexus?

Answer 11

The anterior division of the lower trunk

Question 12

2 nerves off the roots

Answer 12

Dorsal scapular nerve and long thoracic nerve

Question 13

What does the lateral pectoral nerve innervate

Answer 13

Lateral portion of pectoralis major

Question 14

2 nerves off the divisions

Answer 14

Medial and lateral pectoral nerve

Question 15

Pectoralis major nerve root innervation

Answer 15

C5,6 (lateral pectoral nerve) and C7,8,T1 (medial pectoral nerve)

Question 16

What makes up the axillary branch

Answer 16

Posterior cord

Question 17

What makes up the radial branch

Answer 17

Posterior cord

Question 18

What makes up the median branch

Answer 18

Lateral and medial cord

Question 19

Where does long thoracic nerve branch from

Answer 19

C5,6,7 nerve roots

Question 20

Nerves off the posterior cord

Answer 20

Upper, medial (thoracodorsal) and lower subscapular nerves

Question 21

What does the dorsal scapular nerve innervation

Answer 21

Rhomboids and levator scapulae muscle

Question 22

What innervates the supinator

Answer 22

Radial nerve

Question 23

What innervates adductor pollicis

Answer 23

Ulnar nerve

Question 24

The ventral rami of the brachial plexus go between what 2 muscles

Answer 24

Anterior and middle scalene muscles

Question 25

What makes up the posterior cord of the brachial plexus

Answer 25

Posterior divisions of upper, middle and lower trunks

Question 26

What does the suprascapular nerve innervate

Answer 26

Supraspinatus and infraspinatus

Question 27

Nerve root innervation for latissimus dorsi

Answer 27

C6,7,8

Question 28

What does the middle subscapular nerve innervate

Answer 28

Latissimus dorsi

Question 29

What muscles does axillary nerve innervate

Answer 29

Deltoid, teres minor

Question 30

What does the lower subscapular nerve innervate

Answer 30

Teres major and subscapularis

Question 31

Nerve root innervation for supraspinatus and infraspinatus

Answer 31

``` supraspinatus = C4,5,6 Infraspinatus = C5,6 ```

Question 32

Nerve root innervation for teres major

Answer 32

C5,6

Question 33

Where does dorsal scapular nerve branch from

Answer 33

C5 root

Question 34

What innervates abductor pollicis longus

Answer 34

Radial nerve

Question 35

1 nerve off the trunks

Answer 35

Suprascapular nerve

Question 36

What makes up the lateral cord of the brachial plexus

Answer 36

The anterior divisions of the upper and middle trunks

Question 37

What makes up the ulnar branch

Answer 37

Medial cord