1.3 Brachial Plexus

Question 1

What rami spinal nerves does brachial plexus consist of?

Answer 1

C5,6,7,8 and T1

Question 2

This nerve innervates the rhomboids and levator scapulae

Answer 2

dorsal scapular nerve (C5)

Question 3

this nerve innervates serratus anterior muscle, can be compressed by scalene muscles (swimmers)

Answer 3

long thoracic nerve (C5,6,7)

Question 4

• nerve that innervates the teres minor, deltoid, and skin over lower half of deltoid
• comes out of quadrangular space
• fracture of the surgical neck can damge this nerve

Answer 4

Axillary nerve (C5,6)

Question 5

• innervates coracobrachialis, biceps, brachialis, lateral cutaneous nerve of forearm
• flexes shoulder/humerus, flexes elbow/forearm

Answer 5

musculocutanous nerve (C5,6,7)

Question 6

injury to superior part of brachial plexus (C5,6), excessive separation of head and neck (falling on ground, shoulder dystocia at birth), “waiter’s tip position”

Answer 6

Erb’s Palsy

Question 7

injury to inferior part of brachial plexus (C8, T1) , caused by hyperadbduction of the arm (painting a ceiling, grasping tree branch), causes clawhand

Answer 7

Klumpke’s Palsy

Question 8

• from the superior trunk
• innervates supraspinatus, infrapsinatus, and glenoid joint
• artery goes over and nerve goes under the superior transverse scapular ligament that covers the scapular notch

Answer 8

suprascapular nerve (C4,5,6)

Question 9

• comes off lateral cord

- innervates pectoralis major muscle

Answer 9

lateral pectoral nerve (C5,6,7)

Question 10

• comes off medial cord

- innervates pectoralis major and pectoralis minor

Answer 10

Medial pectoral nerve (C8, T1)

Question 11

• comes off medial cord

- supplies skin on medial side of arm and superior part of forearm

Answer 11

Medial cutaneous nerve of arm (medial brachial cutaneous) (C8, T1)

Question 12

• comes off medial cord

- supplies skin on medial side of forearm

Answer 12

Medial cutanous nerve of forearm (medial antebrachial cutaneous) (C8, T1)

Question 13

• comes off posterior cord

- innervates subscapularis muscle

Answer 13

upper subscapular nerve (C5,6)

Question 14

• comes off posterior cord

- innervates latissimus dorsi

Answer 14

thoracodorsal (medial subscapular) (C6,7)

Question 15

• comes off posterior cord

- innervates teres major

Answer 15

lower subscapular nerve (C6,7)

Question 16

• extends shoulder/humerus and elbow/forearm

- extends wrist

Answer 16

Radial nerve (C5-T1)

Question 17

• flexes wrist and fingers

- 3 thumb muscles and lumbricles

Answer 17

Median nerve (C5-T1)

Question 18

most hand muscles,

Answer 18

Ulnar nerve (C8, T1)