1. Dr Nabil Khouri MD, MSc. Ph,D
Anatomy of the Axilla
Dr Nabil Khouri MD, MSc. Ph,D

2. Objectives
Define axilla.
Give its boundaries and contents.

3. Axilla(Arm pit)

4. AXILLA
A pyramid-shaped space between the upper part of the arm and the side of the chest through which major neurovascular structures pass between neck & thorax and upper limbs.
Axilla has an apex, a base and four walls.

5. Axilla is a space 4 Sided pyramid Apex connected to the neck=Inlet
Base Arm pit= Outlet
Anterior wall
Posterior wall
Medial wall
Lateral wall

7. Boundaries of the Axilla
Apex:
Is directed upwards & medially to the root of the neck.
It is called
Cervicoaxillary canal.
It is bounded, by 3 bones:
Clavicle anteriorly.
Upper border of the scapula posteriorly.
Outer border of the first rib medially. 1 C L A R I B V I C L E

8. Base
Axillary fascia and Skin of the arm pit

9. Anterior wall Pectoralis major Pectoralis minor Subclavius muscles
Clavipectoral fascia

10. Clavipectoral facia

11. Pierced by 4 structures 2 inwards
Lymphatics from the infraclavicular nodes to the apical nodes of the axilla.
Cephalic vein
2 outwards
Lateral pectoral nerve
Thoracoacromial artery,
or its branches
Pectoral
Acromial
Deltoid
Clavicular

12. Posterior wall:
Is formed by:
Subscapularis.
Latissimus dorsi.
Teres major muscles.

13. The medial wall:
It is wide and formed by:
Serratus anterior.
Upper 4-5 ribs & Intercostal muscles .

14. The lateral wall:
It is narrow and formed by:
Coracobrachialis.
Biceps brachii.
Bicepital groove of the humerus.

15. Contents of The Axilla Cords and branches of the brachial plexus
Axillary a. & v.
Cords and branches of the brachial plexus
Axillary artery and its branches.
Axillary vein and its tributaries.
Axillary lymph nodes.
Axillary lymphatic vessels
Axillary fat.
Loose connective tissue.
Brachial plexus
The neurovascular bundle is enclosed in connective tissue sheath, called ‘axillary sheath’

16. Lymph nodes An anterior or pectoral group
A posterior or subscapular group
A lateral group
A central group
An apical group

18. Quadrangular space The inferior margin of the Subscapularis
The lateral margin of the long head of the Triceps brachii
The surgical neck of the Humerus
The superior margin of the
Teres major
Passing through the quadrangular space are
Axillary nerve
Posterior circumflex humeral artery and vein.

19. Triangular space
the medial margin of the long head of the triceps brachii muscle;
the superior margin of the teres major muscle;
the inferior margin of the subscapularis muscle
Passing through the triangular space are
circumflex scapular artery and vein

20. Triangular interval The inferior margin of the teres major muscle
The lateral margin of the long head of the Triceps brachii
The shaft of the humerus
Passing through the Triangular interval are
radial nerve