This document was created by Alex Yartsev (dr.alex.yartsev@gmail.com ); if I have used your data or images and forgot to reference you, please email me. Muscles, Innervation and the Compartments of the Upper Limb Organized in an Unintentionally Difficult Manner Fascia and compartments of the shoulder PECTORALIS FASCIA - The only contents is Pectoralis Major; - Pectoralis fascia continue inferiorly as fascia of the anterior abdominal wall - It continues laterally-once it leaves the lateral edge of Pectoralis Major, it becomes AXILLARY FASCIA AXILLARY FASCIA - Continuous with the CLAVIPECTORAL FASCIA - Forms the floor of the axilla CLAVIPECTORAL FASCIA - Deep to the Pectoralis major muscle, the CLAVIPECTORAL FASCIA invests the subclavius muscle and pectoralis minor. - It forms the costocoracoid membrane above pectoralis minor, and the suspensory ligament of axilla below pectoralis minor. The suspensory ligament drags the axillary fascia upwards when the arm is raised, forming the actual “pit” of the armpit - Supraspinous, Infraspinous and Subscapular fascia - The supraspinatus, infraspinatus and subscapularis muscles are contained in their own little fascial compartments Deltoid Fascia - The deltoid has its own fascia, continous with the pectoral fascia and infraspinatus fascia - It has numerous fascial septa which separate the fascicles of the deltoid Clavicle Subclavius Axillary fascia Costocoracoid membrane Axillary fascia Pectoralis minor Suspensory ligament of axilla Lateral pectoral nerve Pectoralis major, wrapped up in pectoralis fascia Supraspinatus fascia Subscapularis fascia Infraspinatus fascia Spine of scapula Clavicle Pectoralis fascia Deltoid fascia Infraspinatus fascia Fascial septa Pectoralis fascia, infraspinatus fascia and deltoid fascia all continue down the arm to form the brachial fascia and Thoracoacromial artery