The Axillary Artery
Definition
Continuation of the subclavian artery.
commences at the outer border of the first rib
Ends at the lower border of the tendon of the Teres major.
There it takes the name of brachial artery.
The vessel is nearly straight when the arm is directed at right angles with the trunk
Concave upward when the arm is elevated above this
Convex upward and lateralward when the arm lies by the side
At its origin the artery is very deeply situated, but near its termination is superficial, being covered only by the skin and fascia.
Three portions; the first part lies above, the second behind, and the third below the Pectoralis minor.
Relations
The first portion of the axillary artery :
anteriorly
Pectoralis major and the coracoclavicular fascia
Crossed by the lateral anterior thoracic nerve, and the thoracoacromial and cephalic veins;
Posteriorly
The first intercostal space,
First intercostal muscle
The first and second digitations of the Serratus anterior
The long thoracic and medial anterior thoracic nerves
The medial cord of the brachial plexus
Laterally : brachial plexus
Medially or thoracic side : the axillary vein which overlaps the artery.
It is enclosed, together with the axillary vein and the brachial plexus, in a fibrous sheath-the axillary sheath-continuous above with the deep cervical fascia.
The second portion of the axillary artery is covered,
Anteriorly
Pectorales major and minor;
Posteriorly
Posterior cord of the brachial plexus
Subscapularis
Medially
The axillary vein,
Medial cord of the brachial plexus
Medial anterior thoracic nerve
Laterally
The lateral cord of the brachial plexus.
The brachial plexus thus surrounds the artery on three sides, and separates it from direct contact with the vein and adjacent muscles.
The third portion of the axillary artery
extends from the lower border of the Pectoralis minor to the lower border of the tendon of the Teres major.
Anteriorly
Covered by the lower part of the Pectoralis major above
Posteriorly
Lower part of the Subscapularis, and the tendons of the Latissimus dorsi and Teres
The branches
First part (1 branch)
Superior thoracic artery (Supreme thoracic artery)
Second part (2 branches)
Thoraco-acromial artery
Lateral thoracic artery
Third part (3 branches)
Subscapular artery
Anterior humeral circumflex artery
Posterior humeral circumflex artery
