Axillary artery
From Ganfyd
The axillary artery is the continuation of the subclavian artery in its course through the axilla.
| Axillary artery | |
|---|---|
 The axillary artery and its surroundings | |
| System: | Arterial |
| Function: | |
| Origin: | Subclavian artery |
| Branches: | Superior thoracic artery, thoracoacromial artery, lateral thoracic artery, subscapular artery, anterior circumflex humeral artery, posterior circumflex humeral artery |
| Insertion: | |
| Arterial supply: | See individual branches |
| Venous drainage: | |
| Lymphatic drainage: | |
| Innervation: | |
| Vertebral levels: | |
| Search for Axillary artery in Gray's. | |
Contents |
Surface Anatomy
Runs in a straight line from the lateral border of the first rib to the inferior border of teres major.
The axillary artery is palpable within the axilla by pressing laterally onto the shaft of the humerus.
Anatomical Course
The axillary artery arises as a continuation of the subclavian artery at the lateral border of the first rib. Its direction varies with the position of the arm, however it always continues distally from its origin. Whilst at its origin it is deep, it has become superficial by the time of passing out from the axilla. Throughout the majority of its course it is covered by pectoralis major, excepting the most distal portion. At the inferior border of teres major, the artery continues as the brachial artery.
The artery is surrounded by the various parts of the brachial plexus. Proximal to pectoralis minor, the plexus lies posteriorly and superiorly to the artery, whilst distally it surrounds the artery as the three cords. Both plexus and artery are surrounded by the axillary sheath, a continuation of the prevertebral fascia.
The artery is crossed by pectoralis minor, which divides it into three parts: first, second and third.
First part
From the lateral border of the first rib to the proximal (anteromedial) border of pectoralis minor.
Second part
The portion of the artery posterior to pectoralis minor.
Third part
The portion of the artery between the inferolateral border of pectoralis minor and the inferior border of the axilla i.e. the inferior border of teres major. At this point it becomes the brachial artery.
Branches
 | To remember the branches easily, the number of branches from each part is the same as the number of the part (1st had 1 branch, 2nd has 2 branches and 3rd had 3). |
First Part
Second Part
Third Part
Relations
First part
- anteriorly
- pectoralis major
- covering fascia and skin
- cephalic vein crosses artery
- posteriorly
- laterally
- cords of brachial plexus
- medially
Second Part
- anteriorly
- pectoralis minor
- pectoralis major
- fascia
- skin
- posteriorly
- posterior cord of brachial plexus
- subscapularis
- shoulder joint
- laterally
- lateral cord of brachial plexus
- medially
- medial cord of brachial plexus
- axillary veins
Third Part
- Anteriorly
- pectoralis major
- medial root of median nerve
- Posteriorly
- Laterally
- coracobrachialis
- biceps brachii
- humerus
- lateral root of median nerve
- musculocutaneous nerve
- Medially
Arterial Supply to
Branches:
Clinical Relevance
- Often lacerated in violent injury
- May be ruptured when relocating an old shoulder dislocation if the artery is stuck to the joint capsule
Variations
- Branches are extremely variable
- An alar thoracic artery from the second part may supply the tissues of the axilla
- The subscapular artery, anterior circumflex humeral artery, posterior circumflex humeral artery and profunda brachii arise from a common branch, and the brachial plexus will surround this common origin.
- The posterior circumflex humeral artery may arise as a branch of profunda brachii
- An anomalous high division may occur at this level into the radial and ulnar arteries.
