Summary The anatomy and physiology of the Axilla of the shoulder

AXILLA
 Known as Armpit
 Pyramidal region between upper thoracic wall & arm
 Shape & size very depending on position of arm
 Provides a passageway for structure: to pass between upper limb & neck
 Consists of apex, base & 4 walls




Borders
 Apex: 1st rib, scapula & clavicle
 Base: skin of armpit, axillary fascia
 Anterior wall → pectoralis major, pectoralis minor & fascia
 Posterior wall → subscapularis, teres major, latissimus dorsi
 Medial wall → 1-4 ribs, intercostal muscles, serratus anterior
 Lateral wall → intertubercular groove

Contents:
 Axillary artery
 Axillary vein
 Axillary lymph nodes
 Lymphatic vessels
 Infraclavicular branches of brachial plexus



ARTERIES
 1st subclavian → passes under clavicle in armpit region → axillary artery (short & runs the
length of scapula)
 As axillary artery exits armpit area → brachial artery
 Most of brachial artery runs along anterior surface of arm
o But there is a branch - deep brachial artery - supplies muscles of arm

, VEINS
 At armpit region: merging of brachial & basilic veins form → axillary vein
o Superficial cephalic vein does NOT merge at same point as basilic vein
 Above axillary vein, cephalic vein meets up with it over the top of the shoulder
o Now it is subclavian vein & runs under clavicle




 Subclavian vein joins up with internal & external Jugular veins draining the head to form
→ Brachiocephalic vein
o Large vein that runs from posterior to anterior over the 1st rib