Brachial Plexus Flashcards Preview

PNS Exam Three > Brachial Plexus > Flashcards

Flashcards in Brachial Plexus Deck (158):
1

What roots form the middle trunk of the brachial plexus?

C7

2

What roots form the inferior trunk of the brachial plexus?

C8 and T1

3

Each trunk of the brachial plexus splits into what structures?

Anterior and posterior divisions

4

The three trunks of the brachial plexus pass over what structure going into the axilla?

The first rib

5

What do the anterior divisions of the brachial plexus supply?

Anterior compartments of the arm and forearm

6

What do the posterior divisions of the brachial plexus supply?

Posterior compartments of the arm and forearm

7

What roots make up the brachial plexus?

Anterior primary rami of C5-T1

8

What does the brachial plexus supply?

Upper extremities

9

In what direction does the brachial plexus travel?

Medial to lateral (over first rib into the axilla)

10

Brachial plexus roots combine to form what structures?

Trunks

11

Trunks of the brachial plexus divide into what structures?

Divisions

12

Divisions of the brachial plexus combine to form what structures?

Cords

13

Cords of the brachial plexus divide into what structures?

Terminal nerves

14

Dorsal scapular nerve carries fibers from what root?

C5 only

15

What muscles are supplied but the dorsal scapular nerve?

Rhomboid major and minor, levator scapulae

16

Each root of the brachial plexus receives a gray ramus communicans from what location?

Sympathetic trunk

17

The roots of the brachial plexus pass between what two muscles into what body triangle?

Between anterior and middle scalene; into posterior triangle

18

Where is the brachial plexus in relation to the subclavian artery?

Posterior and superior

19

What divisions form the lateral cord of the brachial plexus?

Anterior divisions of the superior and middle trunks

20

What fibers make up the lateral cord of the brachial plexus?

C5, C6, and C7

21

The cords of the brachial plexus are named for their relationship to what structure?

Axillary artery

22

What is the position of the lateral cord in relation to the axillary artery?

Lies lateral to the second part of it

23

Which two nerves are formed from roots of the brachial plexus before they combine to form trunks?

Dorsal scapular nerve, long thoracic nerve

24

What does the long thoracic nerve supply?

Serratus anterior muscle

25

What divisions form the medial cord of the brachial plexus?

Anterior division of the inferior trunk

26

What fibers make up the medial cord of the brachial plexus?

C8 and T1

27

Where does the medial cord of the brachial plexus lie in reference to the axillary artery?

Medial to the second part of it

28

What divisions form the posterior cord of the brachial plexus?

Union of the posterior division of all three trunks

29

What fibers make up the posterior cord of the brachial plexus?

C5, C6, C7, C8, and T1

30

Where does the posterior cord of the brachial plexus lie in reference to the axillary artery?

Posterior to the second part of it

31

Levator scapulae and the rhomboids all attach to what part of what bone?

Medial border of the scapula

32

Levator scapulae muscles also receive fibers from what roots other than C5?

C3 and C4

33

What nerves branch off of the superior trunk of the brachial plexus?

Suprascapular nerve and nerve to the subclavius

34

What muscles are supplied by the suprascapular nerve?

Supraspinatus and infraspinatus muscles

35

Suprascapular nerve is formed from what fibers of the brachial plexus?

C5 and C6

36

What do the supraspinatus and infraspinatus muscles have in common?

Both rotator cuff muscles, both originate on the posterior (superficial) surface of the scapula

37

Nerve to the subclavius contains fibers from what roots of the brachial plexus?

C5 and C6

38

Nerve to the subclavius supplies what muscle?

Subclavius

39

What nerves make up the supraclavicular portion of the brachial plexus?

Suprascapular, dorsal scapular, long thoracic, and nerve to subclavius

40

What roots form the superior trunk of the brachial plexus?

C5 and C6

41

The long thoracic nerve contains fibers from what roots?

C5, C6, C7

42

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

Lateral pectoral nerve, musculocutaneous nerve, contribution to the median nerve

43

The lateral pectoral nerve contains fibers from what roots of the brachial plexus?

C5, C6, C7

44

What muscle is supplied by the lateral pectoral nerve?

Pectoralis major

45

What is the pectoralis major muscle's complete nerve supply?

Both the lateral and medial pectoral nerves

46

The musculocutaneous nerve contains fibers from what brachial plexus roots?

C5, C6, C7

47

What muscles are supplied by the musculocutaneous nerve?

Coracobrachialis, biceps brachii (both long and short heads), brachialis (3 muscles, 4 total muscle heads)

48

What muscle belly is directly pierced by the musculocutaneous nerve?

Coracobrachialis

49

What do the muscles supplied by the musculocutaneous nerve all have in common?

They all fill the anterior compartment of the arm

50

Fibers from the musculocutaneous nerve that do not supply the muscles of the anterior compartment of the arm go on to the forearm to become what nerve?

Lateral cutaneous nerve of the forearm

51

What is the supply of the lateral cutaneous nerve of the forearm?

Skin over the lateral aspect of the forearm, not the hand

52

What are the two terminal branches of the lateral cord?

Musculocutaneous and median nerves

53

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

Medial pectoral nerve, medial cutaneous nerve of the arm, medial cutaneous nerve of the forearm, ulnar nerve, and median nerve

54

The medial pectoral nerve contains fibers from what roots of the brachial plexus?

C8 and T1

55

What muscles are supplied by the medial pectoral nerve?

Pectoralis major and minor

56

What fibers of the brachial plexus are contained in the medial cutaneous nerve of the arm?

C8 and T1

57

What is the supply of the medial cutaneous nerve of the arm?

Skin of the medial arm between the axilla and the elbow

58

The medial cutaneous nerve of the arm also receives some fibers from what location?

T2 via the intercostobrachial nerve

59

What fibers make up the medial cutaneous nerve of the forearm?

C8 and T1

60

Where does the medial cutaneous nerve of the forearm leave the medial cord of the brachial plexus in reference to the medial cutaneous nerve of the arm?

Just distal to it

61

What is the supply of the medial cutaneous nerve of the forearm?

Skin over biceps brachii, skin over anterior and medial aspects of forearm distal to the wrist

62

What fibers contribute to the ulnar nerve?

C8 and T1 (sometimes C7)

63

The ulnar nerve travels medial to what artery?

Brachial artery (in the medial bicipital sulcus)

64

Does the ulnar nerve have any branches in the arm?

None

65

When the ulnar nerve reaches the elbow area, it passes under what anatomical structure?

Posterior side of medial epicondyle in the sulcus for the ulnar nerve

66

What is the lay term for the location where the ulnar nerve can be easily palpated near the elbow?

"Funny bone"

67

The ulnar nerve continues into the forearm between the two heads of what muscle?

Flexor carpi ulnaris

68

What muscle flexes digits 2-5 at the DIP joints?

Flexor digitorum profundus

69

What two muscles in the forearm are innervated by the ulnar nerve?

Flexor carpi ulnaris, flexor digitorum profundus

70

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

Dorsal and palmar branches of the ulnar nerve

71

What does the dorsal branch of the ulnar nerve supply?

Skin on the ulnar side of the posterior hand

72

What does the palmar branch of the ulnar nerve supply?

Skin over the hypothenar eminence

73

As the ulnar nerve passes through the wrist, does it pass superficial or deep to the flexor retinaculum?

Superficial

74

What is the supply of the superficial branch of the ulnar nerve?

Skin over palmar aspect of the little finger and medial half of the ring finger

75

What are the hypothenar muscles?

Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi

76

What muscles are supplied by the deep branch of the ulnar nerve?

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

77

Damage to the ulnar nerve can result in what condition?

Claw hand

78

What is another term used for claw hand?

Ape hand

79

What fibers contribute to form the median nerve?

C6, C7, C8, and T1

80

What cords form the median nerve?

Both the medial and lateral cords

81

In what anatomical structure does the median nerve travel through the arm?

Medial bicipital sulcus

82

What is another term for the medial bicipital sulcus?

Bicipital furrow

83

Does the median nerve give off any branches in the arm?

No

84

When the median nerve enters the forearm, it first passes between the two heads of what muscle?

Pronator teres

85

The median nerve crosses the elbow on what side?

Anterior

86

The ulnar nerve crosses the elbow on what side?

Posterior

87

What muscles of the forearm are innervated by the median nerve?

Pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, pronator quadratus, flexor policis longus, and the lateral bellies of the flexor digitorum profundus

88

The median nerve supplies the pronator quadratus, flexor pollicis longus, and the lateral bellies of the flexor digitorum profundus by what of what nerve?

Anterior interosseous nerve of the forearm

89

What is the anterior interosseous nerve of the forearm given off of the median nerve?

In the elbow

90

What nerve passes deep to the flexor retinaculum and goes through the carpal tunnel?

Median nerve

91

Where is the palmar branch of the median nerve given off?

In the distal third of the forearm

92

What is the supply of the palmar branch of the median nerve?

Skin of the thenar eminence, lateral wrist, and palm

93

The median nerve divides into how many common palmar digital nerves after it passes through the carpal tunnel?

3

94

Which lumbricals are supplied by the median nerve?

1 and 2

95

What muscles are supplied by the branches off of the first common palmar digital nerve?

Abductor pollicis brevis, flexor pollicis brevis (superficial head), and opponens pollicis

96

What are the thenar muscles?

Abductor pollicis brevis, flexor pollicis brevis (superficial head), and opponens policis

97

Each common palmar digital nerve splits into what?

Two proper palmar digital nerves

98

Are the proper palmar digital nerves motor or sensory in function?

Sensory only

99

What do the proper palmar digital nerves supply?

Skin over the lateral three and a half digits

100

The median nerve also supplies what extra things?

Periosteum, elbow, radiocarpal joint, midcarpal joints

101

The median nerve usually communicates with what nerve at the wrist?

Ulnar nerve

102

Carpal tunnel syndrome involves the compression of what nerve?

Median nerve (not ulnar nerve)

103

What rotational movement becomes difficult with damage to the median nerve and why?

Pronation; median nerve supplies both pronator muscles

104

What fibers are contained in the superior subscapular nerve?

C5 and C6

105

What muscle is supplied by the superior subscapular nerve?

Subscapularis

106

What fibers are contained in the thoracodorsal nerve?

C6, C7, and C8

107

What muscle is supplied by the thoracodorsal nerve?

Latissimus dorsi

108

How many separate nerves contribute to the supply of the rotator cuff muscles?

4

109

What is the course of the thoracodorsal nerve?

Travels along posterior axillary wall

110

What fibers are contained in the inferior subscapular nerve?

C5 and C6

111

What muscles are supplied by the inferior subscapular nerve?

Subscapularis and teres major

112

What fibers are contained in the axillary nerve?

C5 and C6

113

What is the course of the axillary nerve?

Travels posteriorly around the surgical neck of the humerus

114

What muscles are supplied by the axillary nerve?

Anterior part of deltoid and teres minor

115

Where is the sensory branch of the axillary nerve given off?

At the same location as the branch to teres minor

116

What is the sensory branch of the axillary nerve?

Superior lateral cutaneous nerve of the arm

117

What does the superior lateral cutaneous nerve of the arm supply?

Skin over the lateral shoulder and upper arm

118

What fibers are contained in the radial nerve?

C5, C6, C7, C8, and sometimes T1

119

What general group of muscles is supplied by the radial nerve?

Posterior compartment of the arm and forearm

120

The radial nerve passes where in reference to the elbow as it passes into the forearm?

Anteriorly

121

As it enters the forearm, the radial nerve passes between what two muscles?

Brachialis and brachioradialis

122

What is the course of the radial nerve?

From medial bicipital sulcus to posterior of humerus

123

Which has sensory supply: superficial or deep branch of the radial nerve?

Superficial

124

Which has motor supply: superficial or deep branch of the radial nerve?

Deep

125

What is the course of the superficial branch of the radial nerve?

Follows brachioradialis to distal 1/3 of forearm
Travels between brachioradialis and radius to the posterior surface of the hand

126

The deep branch of the radial nerve penetrates what muscle?

Supinator

127

The deep branch of the radial nerve terminates as what nerve?

Posterior interosseous nerve

128

Before terminating as the posterior interosseous nerve, the deep branch of the radial nerve gives off what branches?

Motor branches to supply posterior forearm muscles

129

What is supplied by the posterior cutaneous nerve of the arm?

Skin on the posterior side of the upper arm

130

Where does the posterior cutaneous nerve of the arm break off?

Upper arm

131

Where does the inferior lateral cutaneous nerve of the arm break off?

Middle arm

132

What muscles are supplied by the muscular branches of the radial nerve given off in the arm?

Triceps brachii, anconeus

133

Where is the posterior cutaneous nerve of the forearm given off?

Upper arm

134

What does the posterior cutaneous nerve of the forearm supply?

Narrow area of skin on the lateral side of the posterior forearm

135

Branches of the radial nerve given off at the lateral epicondyle supply what muscles?

Brachioradialis, extensor carpi radialis longus

136

How is the anconeus muscle supplied by the radial nerve?

By way of a branch off the branch to the medial head of the triceps brachii

137

What part of the triceps brachii is supplied by the radial nerve?

All three heads

138

The superficial branch of the radial nerve gives off what nerves?

Dorsal digital nerves

139

What do the dorsal digital nerves supply?

Radial side of posterior hand, extensor side of the thumb, extensor side of the proximal phalanges of digits 2 and 3, lateral half of the extensor side of the ring finger

140

How does the radial nerve communicate with the ulnar nerve via the superficial branch?

By giving off a communicating branch with the ulnar nerve

141

As the deep branch of the radial nerve continues as the posterior interosseous nerve, what forearm muscles are supplied?

Extensor carpi radialis brevis, supinator, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis

142

What muscles supplied by the deep branch of the radial nerve are not extensor muscles?

Supinator, abductor pollicis longus

143

Are the muscles supplied by the deep branch of the radial nerve primarily extensor or flexors?

Extensors (with two exceptions)

144

What rotational movement is made possible by the radial nerve's motor supply?

Supination (supplies supinator)

145

The radial nerve sends articular branches to what locations?

Shoulder and wrist (NOT ELBOW)

146

Wrist drop is a clinical condition involving damage to what nerve?

Radial nerve

147

What reflexes are impaired due to radial nerve damage?

Triceps and brachioradialis reflexes

148

How can you test for wrist drop with a patient?

Have their arm parallel to the floor in a pronated position, and see if they can extend their arm so their fingers are pointed to the ceiling (if unable to do so, radial nerve is damaged and wrist drop is present)

149

What visual clinical hand sign is seen with damage to the median nerve?

"Benediction/hand of oath"
Thumb, index, and middle fingers up with ring and pinky fingers curled down

150

What is the largest branch of the posterior cord of the brachial plexus?

Radial nerve

151

What is Erb-Duchenne palsy?

Damage to the upper part of the brachial plexus, specifically the C5 and C6 roots

152

What kind of injury can result in Erb-Duchenne palsy?

Any injury that tractions the shoulder downward (example = birth trauma)

153

What nerves are affected by Erb-Duchenne palsy?

Suprascapular, musculocutaneous, and axillary nerves

154

What muscles exhibit atrophy from Erb-Duchenne palsy?

Brachialis, biceps brachii, deltoid

155

The "waiter's tip" hand gesture is seen with what condition from damage to the brachial plexus?

Erb-Duchenne palsy

156

What palsy results from damage to the C8 and T1 roots of the brachial plexus?

Dejerine-Klumpke's palsy

157

What muscles are affected by Klumpke's palsy?

Hand muscles (atrophy of thenar and hypothenar eminences), interossei, flexor carpi ulnaris, medial half of the flexor digitorum profundus

158

What sympathetic eye condition is seen due to damage to the T1 root of the brachial plexus in Klumpke's palsy?

Horner's syndrome