Axillary Region Anatomy

Axilla Question And Answers

Question 1. What is an axilla and what are its boundaries and contents?
Answer:

• The axilla or armpit is a four side pyramidal space located between the upper part of the arm and the chest wall.
• It has an apex, base, anterior, posterior, medial, and lateral walls.

Axilla Apex:

• Axilla is directed upwards and medially towards the root of the neck.
• Axilla is truncated, not pointed.
• The axillary artery and brachial plexus enter the axilla through the apex and the passage is called the cervicoaxillary canal.

Read And Learn More: Upper Limb

Axilla Base:

• Axilla is directed downwards.
• The axillais formed by skin, superficial fascia, and axillary fascia.

Axilla Anterior wall:

• Axilla is formed by:
  • Pectoralis major in front
  • Clavipectoral fascia enclosing pectoralis minor and subclavius deep to pectoralis major muscle

Axilla Posterior Wall:

• Axilla is formed by:
  • Subscapularis above
  • Latissimus dorsi and teres major below

Axilla Medial wall:

• Axilla is formed by:
  • 1st to 4th ribs and their intercostal muscles
  • The upper part of serratus anterior muscle

Axilla Lateral wall:

• Axilla is very narrow
• Axilla is formed by:
  • The upper part of the shaft of the humerus
  • Short head of biceps brachia and coracobrachialis

Axilla Contents

• Axillary artery and its branches
• Axillary vein and its tributaries
• Part of brachial plexus below clavicle
• Five groups of axillary lymph nodes and associated lymphatics
• Long thoracic and intercostobrachial nerves
• Axillary fat and areolar tissue

Axilla Multiple Choice Question

Question 1. Which of the following forms the anterior fold of the axilla?

1. Pectoralis major
2. Pectoralis major and pectoralis minor
3. Pectoral muscles and subclavius
4. Clavipectoral fascia

Answer: 1. Pectoralis major