23/06/2022
🔈 FASCIA OF UPPER LIMB
Anterior wall and floor of axilla.
A. Axillary fascia forms the floor of the axilla and is continuous with the pectoral fascia.
B. The pectoral fascia surrounds the pectoralis major, forming the anterior layer of the anterior axillary wall. The clavipectoral fascia extends between the coracoid process of the scapula, the clavicle, and the axillary fascia.
The fascia of the pectoral region is attached to the clavicle and sternum. The pectoral fascia invests the pectoralis major and is continuous inferiorly with the fascia of the anterior abdominal wall. The pectoral fascia leaves the lateral border of the pectoralis major and becomes the axillary fascia , which forms the floor of the axilla (compartment deep to skin of the armpit). Deep to the pectoral fascia and pectoralis major, another fascial layer, the clavipectoral fascia , descends from the clavicle, enclosing the subclavius and then pectoralis minor, becoming continuous inferiorly with the axillary fascia.
The part of the clavipectoral fascia between the pectoralis minor and subclavius, the costocoracoid membrane , is pierced by the lateral pectoral nerve, which primarily supplies the pectoralis major. The part of the clavipectoral fascia inferior to the pectoralis minor, the suspensory ligament of the axilla , supports the axillary fascia and pulls it and the overlying skin upward during abduction of the arm, forming the axillary fossa (armpit).
The scapulohumeral muscles that cover the scapula, and form the bulk of the shoulder, are also ensheathed by deep fascia. The deltoid fascia descends over the superficial surface of the deltoid from the clavicle, acromion, and scapular spine. From the deep surface of the deltoid fascia, numerous septa (connective tissue partitions) pe*****te between the fascicles (bundles) of the muscle. Inferiorly, the deltoid fascia is continuous with the pectoral fascia anteriorly and the dense infraspinous fascia posteriorly. The muscles that cover the anterior and posterior surfaces of the scapula are covered superficially with deep fascia, which is attached to the margins of the scapula and posteriorly to the spine of the scapula.
