The axilla is a pyramidal space between the upper arm and chest wall. It has an apex pointing upward toward the neck, formed by the clavicle, scapula, and first rib. Its floor is formed by the skin, fasciae, pectoralis minor muscle anteriorly, and latissimus dorsi, teres major, and subscapularis muscles posteriorly. The axilla contains the brachial plexus nerves, axillary artery and vein, lymph nodes, fat, and connective tissue.

1. AXILLA
HUMAN ANATOMY

2. INTRODUCTION
• The axilla (Latin armpit) is a pyramidal space situated
between the upper part of the arm and the chest wall.

4. BOUNDARIES OF AXILLA
An apex
A base
Four walls: Anterior, posterior, medial and lateral

5. Apex/Cervicoaxillary Canal
• It is directed upwards and medially towards the root of the neck.
• It is truncated (not pointed).
• The Apex is bounded by 3 bones:
posterior surface of clavicle Anteriorly
superior border of the scapula Posteriorly
outer border of the first rib Medially

6. BASE OR FLOOR
• It is directed downward
Formed by
skin
Superficial
Axillary fasciae
base

7. Pectoralis minor
Anterior
The pectoralis major
The clavipectoral fascia
pectoralis major
Pectoralis minor
clavipectoral fascia

8. Posterior
Subscapularis
Teres major
Latissimus dorsi
It is formed by
Latissimus dorsi
Teres major
Subscapularis

9. Medial
It is convex laterally and formed by the following.
Serratus anterior muscle
Upper 4-5 ribs and intercostal muscle

10. Lateral
It is very narrow because the anterior and posterior
walls converge on it.
intertubercular groove of the
humerus
Coracobrachialis
Biceps brachii

11. CONTENTS OF AXILLA

12. ❖ Cords and branches of brachial plexus
❖ Axillary artery and its branches
❖ Axillary vein and its tributaries
❖ Axillary lymph nodes
❖ Axillary fat
❖ Loose connective tissue