1. The axilla

Question 1

What is the axilla?

Answer 1

area that lies beneath the GH joint, at junction of upper limb and thorax

Question 2

name the borders of the axilla.

Answer 2

• apex = cervico-axillary canal bounded by 1st rib, clavicle and superior edge of scapula
• posterior wall = subscapularis (overlying scapula), teres major and latissimus dorsi
• anterior wall = pec. major and minor
• medial wall = seratus anterior overlying thoracic wall
• lateral wall = intertubercular groove of humerus

Question 3

describe the contents of the axilla

Answer 3

lateral to medial:

• tendons of biceps brachii and coracobrachialis
• brachial plexus (deep)
• axillary artery
• axillary vein
• axillary lymph nodes

Question 4

what are the 3 main routes by which structures leave the axilla?

Answer 4

1- immediately inferiorly and laterally into upper limb - main route of exit

2- via quadrangular space - gap in posterior wall of axilla, allowing access to posterior arm and shoulder area (e.g. axillary n. and posterior circumflex humeral artery)

3- via clavipectoral triangle - opening into anterior wall of axilla (e.g. entrance of cephalic vein, exit of lateral pectoral nerves)

Question 5

What are the 5 principal groups of axillary lymph nodes.

Answer 5

1. pectoral (anterior) nodes: 3-5 nodes along medial wall of axilla, around lateral thoracic vein and inferior borders of pectoralis minor
2. subscapular (posterior) nodes: 6-7 nodes along posterior axillary fold and subscapular blood vessels
3. humeral (lateral) nodes: 4-6 nodes along lateral wall of axilla, medial and posterior to axillary vein
4. central nodes: 3-4 large nodes deep to pectoralis minor, associated with 2nd part of axillary artery
5. apical nodes: at axilla apex

Question 6

Describe the drainage of lymph by the axillary nodes.

Answer 6

1. pectoral nodes: receive lymph from anterior thoracic wall, inc. most of breast
2. subscapular nodes: receive lymph from posterior aspect of thoracic wall and scapular region
3. humeral nodes: receive nearly all lymph from upper arm
4. central nodes: receive lymph from pectoral, subscapular and humeral nodes
5. apical nodes: receive lymph from all other groups of axillary nodes as well as from lymphatics accompanying proximal cephalic vein

Question 7

What happens to the efferent vessels from apical nodes?

Answer 7

traverse the cervicoaxillary canal and unite to form the subclavian lymphatic trunk

Question 8

Name 3 conditions which can cause axillary node enlargement .

Answer 8

lymphangitis:
1- infection in upper limb (characterised by warm red streaks in skin of limb)
2- infection in pectoral region or breast

3- breast cancer metastases