Axilla

Question 1

Describe the four walls of the axilla

Answer 1

4 walls, apex and base

Base: axillary fascia and skin (armpit)
Apex: cervicoaxillary canal

Anterior wall: pectoralis major and minor

Posterior wall: subscapularis muscle (anterior surface of scapula) + teres major and latissimus dorsi

Lateral wall: humuerus, bicipital groove

Medial wall: serratus anterior (over upper 4-5 ribs)

Question 2

Describe the cervicoaxillary canal and its borders

Answer 2

Aperture of the axilla. Most structures which pass between the neck and upper extremity go through the cervicoaxillary canal

Borders:
Anterior, clavicle
Posterior, scapula
Medial, 1st rib

Question 3

Broadly, what are the contents of the axilla

Answer 3

Great vessels and nerves of the upper extremity, surrounded by loose connective tissue

Vessels and nerves enclosed with the axillary sheath

• Axillary artery and vein
• Brachial plexus (medial lateral posterior cords)
• Intercostobrachial nerve
• Long thoracic nerve (part of brachial, 5-7th)
• Axillary lymph node groups

Question 4

What are the 3 portions of the axillary artery defined by

Answer 4

Relationship to pectoralis minor:

Superior, posterior, and inferior to.

Question 5

At what point does the subclavian artery become the axillary artery

Answer 5

At the lateral edge of the 1st rib

Question 6

At what point does the axillary artery become the brachial artery

Answer 6

At the lower margin or teres major

Question 7

Describe the 1st portion of the axillary artery

Answer 7

1st portion: Supreme thoracic artery, medial/superior to pectoralis minor, supplies thoracic wall 1st an 2nd intercostal spaces

2nd portion: Two branches:

• Thoracoacromial artery
• Lateral thoracic artery