[Plate 418, Brachial Plexus: Schema]page 217
page 218Pyramid-shaped area inferior to glenohumeral joint containing important neurovascular structures to the upper limb
Boundaries
Base: skin of armpit and axillary fascia from arm to thoracic wall
Apex: bounded by the first rib, clavicle, and superior border of the scapula
Anterior wall (anterior axillary fold): pectoralis major and minor
Posterior wall (posterior fold): subscapularis, teres major, latissimus dorsi
Medial wall: ribs 1 through 4, serratus anterior, and intercostal muscles
Lateral wall: intertubercular groove of humerus
Contents (see Section 6-6: Upper Limb: Neurovasculature for details)
Axillary artery and branches
Axillary vein and tributaries
Axillary lymph nodes (five major collections)
Brachial plexus
Fascia
Pectoral fascia
Attaches to clavicle and sternum
Invests the pectoralis major
Extends laterally as the axillary fascia
Continues inferiorly with fascia of abdominal wall
Clavipectoral fascia
Invests subclavius and pectoralis minor
Continues superiorly as the costocoracoid membrane (pierced by the lateral pectoral nerve)
Axillary sheath: invests axillary artery and brachial plexus
Axillary Lymph Nodes
Arranged in five main groups
Apical group
Along medial side of axillary vein and first part of axillary artery
Receives lymph from all other groups
Efferent lymphatic vessels from these nodes form subclavian lymphatic trunk
Pectoral (anterior) group