Editing Axilla (section)

=== '''Axillary     artery''' ===

** Path:
*** Commences at the outer       border of the first rib, as a continuation of the subclavian artery
*** Enters apex of axilla       behind the midpoint of the clavicle
*** Becomes the brachial artery       at the lower border of teres major
*** Enclosed within the       axillary sheath, along with cords of the brachial plexus, to which it is       closely related
*** Surface marking - a line       from the middle of the clavicle to the groove behind coracobrachialis
** Divisions:
*** A1: above pectoralis minor
*** A2: behind pectoralis minor
**** Note that this is the part        of the artery that gives the cords of the brachial plexus their names,        which are their positions relative to A2
*** A3: below pectoralis minor
** Branches:
*** A1 = 1, A2 = 2, A3 = 3.
*** SALSAP
*** A1
**** Superior thoracic artery        (supplies pec major and minor)
*** A2
**** Acromiothoracic - runs        over pec minor to pierce the clavipectoral fascia and supply four        branches (clavicular, deltoid, acromial and pectoral)
**** Lateral thoracic - runs        laterally along the lower border of pec minor to supply serratus        anterior, pec major, pec minor and female breast tissue
*** A3
**** Subscapular - largest        branch of the axilla, runs down the posterior wall of the axilla, then        divides into circumflex scapular artery and thoracodorsal artery
**** Anterior circumflex        humeral - runs deep to coracobrachialis and both heads of biceps,        passes around the neck of humerus to anastomose with the posterior        circumflex
**** Posterior circumflex        humeral - larger branch, passes through the posterior axillary wall,        supplies deltoid, triceps and shoulder joint
** Variant anatomy
*** Highly variable
*** Branches especially can       have variable origins, common trunks
*** Anomalous high division       into radial and ulnar arteries
** Surgical approach:
*** See 'arterial exposures'       under Vascular Operations