Anatomy--Upper Limb

Front 1

what nerve(s) innervate the anterior compartment of the forearm?

Back 1

-median
-flexor carpi ulnaris (ulnar n.)
-1/2 flexor digitorum profundus (ulnar n.)

Front 2

what nerve(s) innervate the posterior compartment of the forearm?

Back 2

radial n.

note: brachioradialis is a flexor

Front 3

what nerve(s) innervate the anterior compartment of the arm?

Back 3

musculocutaneous

Front 4

what nerve(s) innervate the posterior compartment of the arm?

Back 4

radial

Front 5

what are the major muscles of the arm?

Back 5

-biceps
-brachialis
-triceps (posterior)

Front 6

what nerve(s) innervate the hand?

Back 6

median and ulnar nerves

exc: lateral two lumbricals come from the median n.

THERE ARE NO INTRINSIC EXTENSORS IN HAND.

Front 7

dorsal scapular n.

Back 7

-arises from C5
-innervates rhomboid muscles

if you can retract your shoulder blades, it is intact

Front 8

muscles comprising the rotator cuff

Back 8

-supraspinatus (abduction)
-infraspinatus (lateral rotation)
-teres minor
-subscapularis (medial rotation of humerus)

MNEMONIC: SITS

Front 9

suprascapular n.

Back 9

-arises from C5-6 (upper trunk)
-innervates supraspinatus and infraspinatus

Front 10

long thoracic n.

Back 10

-C5-7
-innervates serratus anterior

Front 11

from where in the brachial plexus does the axillary nerve arise, and what muscles does it innervate?

Back 11

-C5-6
-posterior cord
-innervates teres minor and deltoid muscles

Front 12

where is the dermatome for C5?

Back 12

upper side of the shoulder

Front 13

where is the dermatome for C6?

Back 13

thumb

Front 14

how would you test to see if the axillary nerve was damaged?

Back 14

abduction of the shoulder is not really possible

also, there would be decreased sensory response to the upper side of the shoulder

Front 15

what is a definite sign of a radial nerve injury?

Back 15

limp wrist and the inability to extend it at all

Front 16

what would a lack of sensation in the top part of the shoulder indicate

Back 16

either an avulsion of C5 or damage to the axillary nerve itself

Front 17

from what roots does the radial nerve derive and how would you test if it was intact?

Back 17

-C5-T1 (but only thru C8 posteriorly)
-sensation all down back of arm and forearm, but the best place to test dermatome is webbing of fingers
-responsible for extension

Front 18

what are the forearm flexors supplied by?

Back 18

median nerve

EXCEPTION:
-flexor carpi ulnaris is supplied by ulnar nerve
-FDP gets dual innervation: 2 lateral get median; 2 medial get ulnar

Front 19

what are the hand intrinsics supplied by?

Back 19

ulnar nerve

EXCEPTION:
-thenar (thumb) intrinsics
-lumbricals from FDP are innervated by the same nerve as innervating FDP

Front 20

what comprise the intrinsic hand muscles?

Back 20

-thenar/hypothenar
-interosseus muscles
-lumbricals

Front 21

what forearm muscles does the median nerve innervate? any exceptions?

Back 21

flexor muscles

with the exception of the:
-flexor carpi ulnaris (ulnar n.)
-flexor digitum profundus (medial half)

Front 22

what hand muscles are innervated by the median nerve?

Back 22

-thenar muscles
-lumbricals that originate from LATERAL two profundus tendons

Front 23

what muscles does the ulnar nerve innervate in the hand? any exceptions?

Back 23

all intrinsics

EXCEPT:
thenar muscles and lumbricals innervated by median nerve

Front 24

what muscles comprise the forearm innervated by the ulnar nerve?

Back 24

-flexor carpi ulnaris
-flexor digitorum profundus (medial half)

Front 25

where is the major sensory component of the ulnar nerve?

Back 25

medial side of hand (last 2 fingers)

Front 26

not being able to oppose thumb with fingers would indicate what injury?

Back 26

damage to the median nerve at the wrist

Front 27

abductor pollicis brevis

Back 27

-abducts thumb
-most proximal thenar

Front 28

opponens pollicis

Back 28

-opposes thumb and brings it against fingers
-lies deep to abductor pollicis brevis

Front 29

thenar mnemonic

Back 29

OAF:
Opponens
Abductor
Flexor

Meat LOAF: muscles are supplied by the median nerve

Front 30

where are the interosseus muscles and what nerve innervates them?

Back 30

run between the finger bones and are innervated by the ulnar nerve

Front 31

supraspinatus

Back 31

part of the rotator cuff
innervated by suprascapular (C5)
abducts the arm

Front 32

infraspinatus

Back 32

part of rotator cuff
innervated by suprascapular
laterally rotates the arm

Front 33

lateral rotation of the arm

Back 33

infraspinatus (suprascapular n.) and teres minor (axillary n.) muscles

Front 34

teres minor

Back 34

part of rotator cuff
innervated by axillary nerve
laterally rotates the arm

Front 35

subscapularis

Back 35

innervated by U/L subscapular ns
medially rotates/adducts arm

Front 36

cord segments of brachial plexus

Back 36

lateral: C5-C7
posterior: C5-T1
medial: C8-T1

Front 37

trunk segments of brachial plexus

Back 37

upper: C5-6
middle: C7
lower: C8-T1

Front 38

what roots does the musculocutaneous nerve derive and what muscles does it innervate?

Back 38

-C5-C7
-biceps, brachialis

Front 39

myotome principle

Back 39

-muscles supplied by a single spinal cord segment
-run proximal to distal (away from the body)

Front 40

dermatome principle

Back 40

-part of skin that receives sensory input from a particular spinal cord segment
-run pre-axial to post-axial

Front 41

why is damage to the radial nerve inadvisable?

Back 41

it has no insurance--it is responsible for all extensory muscles

Front 42

what nerve innervates the triceps?

Back 42

the radial nerve (and ONLY this nerve)

Front 43

major bones of the arm/forearm

Back 43

-humerus
-radius
-ulna

Front 44

what nerve supplies the deltoid?

Back 44

axillary nerve

Front 45

motor/sensory test for musculocutaneous nerve

Back 45

M: flex biceps
S: lateral side of forearm

Front 46

motor/sensory test for ulnar nerve

Back 46

M: ad/abduct fingers
S: pinkie finger (flex distal joint)

Front 47

motor/sensory test for median nerve

Back 47

M: flex distal joint of index finger
S: palm of hand

Front 48

what do the superscapular and axillary nerves have in common?

Back 48

they are both supplied from the upper part of the brachial plexus

Front 49

Erb's palsy

Back 49

caused by difficulty in labor, often results in damage to the upper brachial plexus (C5-C7)

Front 50

where in the hand would a T1 injury cause sensory loss?

Back 50

it wouldn't--the T1 dermatome is not in the hand! (post-axial side of arm)

Front 51

what are the three signs of T1 damage regarding the ANS?

Back 51

-myosis
-anhydrosis
-ptosis

also known as Horner's Syndrome--it interrupts the sympathetic chain

Front 52

carpal tunnel syndrome

Back 52

wasting of the thenar muscles and the lateral two lumbricals

Front 53

what type of lesion causes a partial claw hand?

Back 53

ulnar nerve lesion (which also includes wasting of 1st dorsal interosseus muscle)

Front 54

what type of injury causes a full claw hand?

Back 54

a combined median & ulnar nerve lesion OR a lesion on the lower brachial plexus