Brachial Plexus

Question 1

list the motor ONLY nerves of the brachial plexus?

Answer 1

1. dorsal scapular
2. subclavian nerve
3. long thoracic nerve
4. suprascapular
5. subscapular
6. medial pectoral
7. lateral pectoral

Question 2

list the sensory ONLY nerves of the brachial plexus?

Answer 2

1. medial cutaneous nerve of arm

2. medial cutaneous nerve of forearm

Question 3

list the sensory AND motor nerves of the brachial plexus?

Answer 3

1. radial nerve
2. axillary nerve
3. musculocutaneous nerve
4. median nerve
5. ulnar nerve

Question 4

where is the long thoracic nerve located and what happens if it is damaged?

Answer 4

superficial surface of serratus anterior, causes winged scapula, weakened protraction of scapula and difficulty abducting the arm above horizontal

Question 5

what 3 muscles does the dorsal scapular nerve innervate?

Answer 5

levator scapulae, rhomboid major, rhomboid minor

Question 6

what does the suprascapular nerve innervate?

Answer 6

motor: supraspinatus, infraspinatus
sensory: glenohumeral joint

Question 7

what does the nerve to subclavius innervate?

Answer 7

motor: subclavius
sensory: sternoclavicular joint

Question 8

positioning of the pectoral nerves relative to each other?

Answer 8

the lateral pectoral nerve is actually medial body position, and the medial pectoral nerve is lateral

Question 9

what does the lateral pectoral nerve innervate?

Answer 9

pectoralis major

Question 10

what does the medial pectoral nerve innervate?

Answer 10

pectoralis major, pectoralis minor

Question 11

what does upper subscapular nerve innervate?

Answer 11

subscapularis

Question 12

what does lower subscapular nerve innervate?

Answer 12

subscapularis, teres major

Question 13

what does the axillary nerve innervate?

Answer 13

motor: deltoid, teres minor
sensory: skin over upper and lateral arm, glenohumeral joint

Question 14

how can the axillary nerve be damaged, and what occurs as a result?

Answer 14

fx surgical neck of humerus, dislocation of glenohumeral joint, compression from incorrect crutch use, misplaced IM injection
result: atrophy of deltoid, cutaneous sensory loss, difficulty in abduction

Question 15

what motor functions does the radial nerve innervate?

Answer 15

all muscles in the posterior compartments of the arm and forearm (triceps brachii, brachioradialis, extensors and abductors, supinator, anconeus)

Question 16

what sensory functions does the radial nerve innervate?

Answer 16

skin on posterior aspects of arm, forearm and the dorsal lateral surface of hand (thumb, 1st 2 fingers)

Question 17

what could potentially damage the radial nerve and what are the symptoms?

Answer 17

midshaft fx of humerus damage radial nerve during its course along radial groove
sx: associated with posterior muscles of forearm and skin on the dorsum of hand (every muscle distal to where break occurs)

Question 18

motor innervations of musculocutaneous nerve?

Answer 18

all muscles in the anterior compartment of arm (biceps, coracobrachialis, brachialis)

Question 19

sensory innervation of musculocutaneous nerve?

Answer 19

skin on lateral aspect of forearm (lateral cutaneous nerve of forearm) (ulnar side)

Question 20

motor innervations of median nerve?

Answer 20

all muscles in the anterior compartment of forearm EXCEPT flexor carpi ulnaris and medial half of flexor digitorum profundus, also innervates the thenar muscles of the thumb and lateral 2 lumbricals

Question 21

sensory innervations of the median nerve?

Answer 21

skin on the tips of lateral 3.5 digits and lateral palmar surface (“median is money”)

Question 22

when you make the number “3” sign with your hand, which nerves are you testing the sensory function of?

Answer 22

median (lateral 3 digits - thumb) and ulnar (medial 2.5 digits)

Question 23

motor innervation of the ulnar nerve?

Answer 23

flexor carpi ulnaris, medial half of flexor digitorum profundus, all intrinsic muscles of the hand (EXCEPT thenar muscles of thumb and lateral 2 lumbricals)

Question 24

sensory innervation of ulnar nerve?

Answer 24

skin on the medial 1.5 digits and medial palmar and dorsal hand surfaces

Question 25

trace lymph flow in the upper extremity

Answer 25

pectoral and humeral and subscapular lymph nodes drain to the central node in the axilla, central drains to apical, apical drains to infraclavicular, infraclavicular drains to subclavian lymphatic trunk, subclavian lymphatic trunk drains to the right or left lymphatic ducts

Question 26

which lymph nodes can be palpated?

Answer 26

axillar, cervical, inguinal nodes