Axilla and Brachial Plexus Flashcards Preview

Structure and Function Test 1 > Axilla and Brachial Plexus > Flashcards

Flashcards in Axilla and Brachial Plexus Deck (87)
Loading flashcards...
1
Q

A pyramidal shaped space which contains fat and many neurovascular structures. It is considered the portal to the upper limb from the neck

A

Axilla

2
Q

The arterial supply, venous drainage, lymphatic drainage and nerve supply of the upper limb all pass through the

A

Axilla

3
Q

The axilla contains many lymph nodes which receive drainage from the

A

Upper limb, anterior chest wall (including breast), back, and neck

4
Q

What is the structure of the axilla?

A

Three walls, a apex, and a base (triangular pyramid)

5
Q

The ANTERIOR wall of the axilla is composed of the

A

Pectoralis major and pectoralis minor

6
Q

The POSTERIOR wall of the axilla is composed of the

A

Subscapularis, latissimus dorsi, and teres major

7
Q

The MEDIAL wall of the axilla is composed of the

A

Serratus anterior

8
Q

Formed by the bicipital groove of the humerus, where the anterior and posterior walls converge

A

Lateral “wall” of axilla

9
Q

Attaches to the lateral lip of the groove

A

Pectoralis major

10
Q

Attaches to the floor of the groove

A

Latissimus dorsi

11
Q

The groove contains the tendon of the long head of the

A

Biceps femoris

12
Q

An aperture between the clavicle and the first rib which communicates between the axilla and the base of
the neck

A

Upper apex of the axilla

13
Q

Contains fat, lymph nodes, neurovascular structures, short head of biceps brachii and coracobrachialis

A

Axilla

14
Q

The continuation of the subclavian artery (changes its name as it passes the first rib and enters this structure)

A

Axillary artery

15
Q

The pectoralis minor muscle crosses in front of the axillary artery and divides the artery into which three parts?

A

1st part: proximal to the pec minor
2nd part: behind the pec minor
3rd part: distal to the pec minor

16
Q

The third part ends as the artery passes the inferior border of the teres major muscle (thus leaving the axilla and entering the arm), where it is continuous with the

A

Brachial Artery

17
Q

The axillary artery has six branches in the axilla. The 1st part has one branch called the

A

Superior thoracic artery

18
Q

The 2nd part of the axillary artery has two branches, called the

A

Thoracoacromial artery and lateral thoracic artery

19
Q

The 3rd part of the axillary artery has three branches, called the

A

Subscapular, anterior humeral circumflex, and posterior humeral circumflex arteries

20
Q

The nerve supply to the upper limb: provides the sensory and motor innervation to the upper limb

A

Brachial Plexus

21
Q

The brachial plexus arises from nerves in the

A

Neck and upper thorax

22
Q

The portion of the brachial plexus within the axilla consists mostly of the

A

Cords of the plexus

23
Q

The three cords surround the axillary artery and are named according to their position relative to the artery. They are called the

A

Lateral, medial, and posterior cords

24
Q

Connective tissue which surrounds the axillary artery and brachial plexus

-an evagination of deep fascia of the neck

A

Axillary sheath

25
Q

Because the axillary sheath holds the elements of the brachial plexus against the axillary artery, the nerves may be compressed by

A

Aneurysms of the artery

26
Q

The proximal continuation of the basilic vein which changes its name when it crosses the lower border of the teres major to enter the axilla

A

Axillary vein

27
Q

In addition to receiving other deep veins within the axilla, the axillary vein receives the

A

Cephalic vein

28
Q

The axillary vein is NOT within the axillary sheath, rather it is

A

Anterior to the sheath

29
Q

Important clinically due to their drainage of the breast.

Also receives drainage from the upper limb, chest wall, neck and back

A

Axillary lymph nodes

30
Q

Axillary lymph nodes drain to the subclavian lymph trunk which, on the left, drains into the

A

Thoracic duct

31
Q

Axillary lymph nodes drain to the subclavian lymph trunk which, on the right, drains into the

A

Right lymphatic duct

32
Q

Receive drainage from the anterior chest wall and breast

A

Anterior axillary lymph nodes

33
Q

Receive drainage from the posterior chest wall

A

Posterior axillary lymph nodes

34
Q

Receive drainage from the upper limb

A

Lateral axillary lymph nodes

35
Q

The anterior, lateral, and posterior lymph nodes drain into the

A

Central and apical nodes

36
Q

The efferent drainage from the apical nodes forms the

A

Subclavian trunk

37
Q

Because of this anatomy, the anterior, central, and apical axillary lymph nodes are interposed in the pathway of cancerous emboli from the breast before they reach the

A

Venous blood stream

38
Q

Allows for directed and accurate assessment of axillary involvement in breast cancer with minimal morbidity

-Replacing axillary lymph node dissection (ALND) as go to treatment

A

Sentinel lymph node biopsy (SLNB)

39
Q

A colored dye and a radioactive dye are injected into the region of the tumor and then the very few lymph nodes to which the dye drains are removed

A

SLNB

40
Q

A network of nerve fibers that arise from multiple sources, intermingle, and then give rise to nerves that contain nerve fibers from these multiple sources

A

Nerve plexus

41
Q

In the case of the brachial plexus, the multiple sources of nerve fibers are the anterior rami of

A

C5 through T1

42
Q

These fibers intermingle in the trunks and cords of the plexus and then give rise to nerves that contain combinations of nerve fibers from different spinal level between

A

C5 and T1

43
Q

The radial nerve contains nerve fibers from

A

C5, C6, C7, and C8

44
Q

The musculotaneous nerve contains nerve fibers from

A

C5, C6, and C7

45
Q

The median nerve contains nerve fibers from

A

C6,C7, C8, and T1

46
Q

Begins in the neck (supraclavicular portion) and continues into the axilla (infraclaviculr portion)

A

Brachial plexus

47
Q

As the nerve fibers pass from the neck to the axilla, they sort themselves into

A

Anterior and posterior divisions (distribute to anterior and posterior portions of the limb)

48
Q

These divisions will then be bundled together by connective tissue into three

A

Cords

49
Q

The lateral and medial cords contain only

A

Anterior division nerve fibers

50
Q

The posterior cord contains only

A

Posterior division nerve fibers

51
Q

The cords divide to give rise to the

A

Terminal nerves

52
Q

What are three nerves that contain anterior division fibers?

A

Musculotaneous, median, and ulnar nerves

53
Q

What are two nerves that contain posterior division fibers?

A

Radial and axillary nerves

54
Q

Within the brachial plexus, collateral nerves arise which innervate proximal structures in the

A

Shoulder and axilla regions

55
Q

Innervate the muscles that form the posterior wall of the axilla

A

The three subscapular nerves (from posterior cord)

56
Q

The lateral and medial pectoral nerves (from lateral and medial cords) innervate the muscles that form the

A

Anterior wall of the axilla

57
Q

Innervates the muscle on the medial wall of the axilla

A

Long thoracic Nerve

58
Q

The dorsal scapular and suprascapular nerves innervate muscles of the

A

Shoulder girdle

59
Q

Innervates all of the muscles of the anterior compartment of the arm

A

Musculocutaneous nerve

60
Q

Innervates most of the muscles of the anterior compartment of the forearm (the remaining muscles are innervated by the ulnar nerve)

A

Median nerve

61
Q

Innervates most of the muscles of the anterior compartment of the hand (the remaining muscles are innervated by the median nerve)

A

Ulnar nerve

62
Q

Innervates all of the muscles of the posterior compartment of the arm and forearm

A

Radial nerve

63
Q

Innervates only two muscles, the deltoid and teres minor

A

Axillary nerve

64
Q

In the upper limb, the more proximal muscles are innervated by the

A

Higher spinal cord segments

65
Q

The more distal muscles of the upper limb are innervated by

A

Lower spinal cord segments

66
Q

The muscles of the shoulder are innervated by

A

C5 and C6

67
Q

The muscles of the hand are innervated by

A

C8 and T1

68
Q

This means, for example, that although the median nerve contains nerve fibers from C6 through T1, the branches of the median nerve that innervate:

  1. ) proximal forearm muscles
  2. ) distal forearm muscles
  3. ) hand muscles

Contain fibers from?

A
  1. ) C6 and C7
  2. ) C7 and C8
  3. ) C8 and T1
69
Q

Also provide cutaneous innervation

A

Nerves of the brachial plexus

70
Q

The most important region clinically for cutaneous innervation is the

A

Hand

71
Q

The palmar surface of the hand receives cutaneous sensory information from the

A

Median and Ulnar nerves

72
Q

The dorsum of the hand receives cutaneous sensory innervation from the

A

Radial and Ulnar nerves (w/ small contribution from median nerve)

73
Q

The segmental distribution of cutaneous sensory innervation is called the

A

Dermatomal innervation of the limb

74
Q

In general, the higher spinal cord segments provide sensory innervation to the

A

Lateral side of the upper limb

75
Q

In general, the lower spinal cord segments provide sensory innervation to the

A

Medial side of the upper limb

76
Q

In general, pre-plexus nerve injuries (i.e. injuries to the spinal cord, spinal nerve, anterior rami or trunks) will result in

A

Dermatomal sensory losses and segmental muscular weakness

77
Q

Will result in cutaneous nerve sensory losses and muscle loss related to specific peripheral nerves (e.g. muscles innervated by the radial nerve, the median
nerve, the ulnar nerve, etc.)

A

Post-plexus nerve injuries (injuries to terminal or collateral nerves)

78
Q

There are three nerves in the operative field during ALND that are susceptible to injury and deserve special note, what are they?

A
  1. ) Long thoracic nerve
  2. ) Thoracodorsal nerve
  3. ) Intercostobrachial nerve
79
Q

Arises in the neck from branches of the anterior rami of cervical vertebrae C5, C6, and C7 and innervates the important serratus anterior muscle

A

Long thoracic nerve

80
Q

Injury to the long thoracic nerve may paralyze the serratus anterior. Patient would then have a hard time

A

Raising their hand (i.e. impaired upward rotation of the scapula

81
Q

Arises from the posterior cord of the brachial plexus, passes through the axilla, and descends on the posterior wall to innervate the latissimus dorsi muscle

A

Thoracodorsal nerve

82
Q

Arises as a branch of the second intercostal nerve. It crosses the axilla to reach the medial side of the arm, where it provides cutaneous sensory innervations

A

Intercostobrachial nerve

83
Q

Injury to the intercostobrachial nerve during ALND can result in

A

Chronic postoperative pain in region innervated

84
Q

The only bony connection to the axial skeleton

A

Sternoclavicular Joint

85
Q

Innervates proximal muscles: intrinsic shoulder muscles and axillary wall muscles

A

Brachial Plexus

86
Q

Paralysis of muscles innervated by same terminal nerve or collateral nerve

A

Post-plexus lesion (injury to infraclavicular portion of plexus)

87
Q

Weakness (paresis) of
muscles of same
segmental innervation

A

Pre-plexus lesion (Injury to supraclavicular portion)

Decks in Structure and Function Test 1 Class (61):