Brachial Plexus Part 2

Question 1

What nerves branch off of the lateral cord of the brachial plexus?

Answer 1

lateral pectoral nerve and musculocutaneous nerve

Question 2

Where does the lateral pectoral nerve receive fibers from?

Answer 2

C5-C7

Question 3

What supplies the pectoralis major?

Answer 3

lateral pectoral nerve (and medial pectoral nerve of the medial cord)

Question 4

What structures combine to form the “M” of the brachial plexus?

Answer 4

lateral cord, medial cord, and musculocutaneous nerve

Question 5

T/F: the musculocutaneous nerve is one of 2 terminal branches of the medial cord.

Answer 5

False; it is one of 2 terminal branches of the LATERAL cord

Question 6

What cord levels contribute fibers to the musculocutaneous nerve?

Answer 6

C5-C7

Question 7

What muscles are supplied by the musculocutaneous nerve?

Answer 7

Corocobrachialis, Biceps brachii (both heads), and the brachialis

Question 8

As the musculocutaneous nerve continues between the biceps brachii and the brachialis into the forearm, what nerve does it become?

Answer 8

the lateral cutaneous nerve of the forearm

Question 9

What nerve supplies skin over the lateral aspect of the forearm, but not the hand?

Answer 9

lateral cutaneous nerve of the forearm

Question 10

What two (major) nerves are supplied by the terminal branches of the lateral cord?

Answer 10

musculocutaneous and median nerves

Question 11

T/F: all of the branches off of the medial cord have “medial” in their name.

Answer 11

False; ulnar nerve, median nerve, and radial nerve are also supplied by the medial cord

Question 12

What are the branches off the medial cord of the brachial plexus?

Answer 12

medial pectoral nerve, medial cutaneous (brachial) nerve of the arm, medial cutaneous (antebrachial) nerve of the forearm, the ulnar nerve, and the median nerve.

Question 13

Where does the medial pectoral nerve receive fibers?

Answer 13

C8 and T1

Question 14

What muscles are supplied by the medial pectoral nerve?

Answer 14

pectoralis major and minor

Question 15

Where does the medial cutaneous nerve of the arm receive fibers?

Answer 15

C8 and T1 (and some from T2 through a communication)

Question 16

What nerve supplies the skin of the medial arm between the axilla and the elbow?

Answer 16

medial cutaneous nerve of the arm

Question 17

What nerve does the medial cutaneous nerve of the arm communicate with to receive some fibers from T2?

Answer 17

intercostobrachial nerve

Question 18

What cord leves contribute fibers to the medial cutaneous nerve of the forearm?

Answer 18

C8 and T1

Question 19

Which nerve supplies the skin over the biceps brachii and the skin over the anterior and medial aspects of the forearm distal to the wrist?

Answer 19

medial cutaneous nerve of the forearm

Question 20

T/F: the ulnar nerve is one of two terminal branches of the medial cord.

Answer 20

True

Question 21

What cord levels contribute to the ulnar nerve?

Answer 21

C8, T1, and sometimes C7

Question 22

T/F: the ulnar nerve travels lateral to the brachial artery in the medial bicipital sulcus.

Answer 22

False; travels medial to the brachial artery

Question 23

How many branches does the ulnar nerve give off in the arm?

Answer 23

zero

Question 24

Where does the ulnar nerve cross the elbow?

Answer 24

on the posterior side of the medial epicondyle in the sulcus for the ulnar nerve

Question 25

Where does the ulnar nerve continue into the forearm?

Answer 25

between the two heads of the flexor carpi ulnaris

Question 26

What muscles of the forearm are supplied by the ulnar nerve?

Answer 26

flexor carpi ulnaris and the medial half of the flexor digitorum profundus

Question 27

What sensory branches are given off in the forearm by the ulnar nerve?

Answer 27

dorsal branch of the ulnar nerve and the palmer branch of the unlnar nerve

Question 28

What nerve supplies the skin on the ulnar side of the posterior hand?

Answer 28

dorsal branch of the ulnar nerve

Question 29

What nerve supplies the skin over the hypothenar eminence?

Answer 29

palmar branch of the ulnar nerve

Question 30

T/F: the ulnar nerve travels deep to the flexor carpi ulnaris and passes deep to the flexor retinaculum before dividing into two branches.

Answer 30

False; travels superficial to the flexor retinaculum

Question 31

What does the ulnar nerve divide into after passing the flexor retinaculum?

Answer 31

superficial and deep branches

Question 32

T/F: the superficial branch of the ulnar nerve divides into 2 terminal branches (proper palmer branches) that supply the palmer aspect of the little finger and medial half of the ring finger.

Answer 32

False; divides into 3 terminal branches to do this

Question 33

The deep branch of the ulnar nerve curves towards the thenar eminence and gives off branches. What muscles does it supply?

Answer 33

abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, adductor pollicis, deep head of the flexor pollicis brevis, all interossei (dorsal and palmar), and lumbricals 3 and 4

Question 34

What clinical consideration is associated with the ulnar nerve?

Answer 34

claw hand