Brachial Plexus

Question 1

brachial plexus is formed by union of which spinal nerves

Answer 1

cervical spinal nerves C5-C8 and T1

Question 2

the lateral pectoral nerve is a branch of which cord of the brachial plexus?

Answer 2

lateral

Question 3

what cord of the brachial plexus is the musculocutaneous nerve a branch of?

Answer 3

lateral

Question 4

what important nerve of the arm receives contribution from both the lateral and medial cords?

Answer 4

median nerve

the medial cord receives small contribution from lateral cord

Question 5

what cord of the brachial plexus is the ulnar nerve a branch of?

Answer 5

medial cord

Question 6

the radial nerve is a continuation of which cord of the brachial plexus?

Answer 6

posterior cord

Question 7

the cords of the brachial plexus (lateral, medial, and posterior) are named for the relationship to what structure?

Answer 7

axillary artery/vein

Question 8

the axillary nerve is a branch of what brachial plexus cord?

Answer 8

posterior

Question 9

thoracodorsal nerve, innervating the deep surface of the latissimus dorsi, branches from the ____ cord of the brachial plexus

Answer 9

posterior

Question 10

the greater auricular nerve passes superficial to the sternocleidomastoid to supply what portion of the face?

Answer 10

posterior face

Question 11

which of these does not originate from the cords of the brachial plexus?
radial nerve
median nerve
phrenic nerve
musculocutaneous nerve

Answer 11

phrenic nerve does not originate from cords of brachial plexus

(cervical plexus, C2-C4, contributes to phrenic nerve, as well as supplies sensation to neck and posterior scalp and innervation to the infrahyoid muscles)

Question 12

the trunks of the brachial plexus exit the neck by passing through these two muscles

Answer 12

anterior and middle scalene muscles

Question 13

tumors of the apex of the lung known as Pancoast tumors have what effect?

Answer 13

compress lower roots of brachial plexus, causing pain and weakness of medial forearm and hand. May also compress sympathetic chain to produce Horner’s syndrome

Question 14

what do the superficial and deep branches of the radial nerve do, respectively?

Answer 14

superficial radial nerve - sensation to back of hand and thumb
deep radial nerve - innervates muscles of extensor forearm

Question 15

which nerve of the forearm may be transposed medially to relieve compression causing weakness of the intrinsic muscles of the hand?

Answer 15

ulnar nerve - has a close relationship to the medial epicondyle