1 8 THE SUPERIOR EXTREMITY 



Dissection. If the subject is a female the dissector should 

 endeavour to make out some of the details described above. 

 The strands called the ligaments of Cooper were noted, as the 

 skin was removed from the surface of the gland (p. 17). Now 

 the skin of the areola must be detached from the surface of 

 the gland, and reflected towards the nipple. As that is done 

 try to make out the lactiferous sinuses (Fig. 7) and the terminal 

 ducts. If possible pass a bristle into one or other of the ducts 

 at the apex of the nipple and trace the duct to a lactiferous 

 sinus, and from the sinus trace the deeper part of the duct into 

 the substance of the gland. Next, with the aid of the scalpel, 

 gradually detach the gland from the deep fascia. Begin at 

 the upper border, and, as the gland is displaced, note the strands 

 of the stroma which connect its deep surface with the deep 

 fascia. It is along those strands that blood-vessels and lymph 

 vessels, which pierce the substance of the pectoralis major, 

 enter and leave the gland. Trace a process of the lateral 

 margin of the gland into the axilla behind the anterior axillary 

 fold. Finally, remove the gland by cutting the mammary 

 branches of the lateral thoracic artery at the lateral margin, 

 and the mammary branches of the anterior perforating arteries 

 at the medial margin, then examine the deep fascia of the 

 pectoral and axillary regions. 



Deep Fascia. The deep fascia of the pectoral region is 

 a thin membrane which closely invests the pectoralis major. 

 It is attached above to the clavicle, and medially to the 

 front of the sternum. Below, it is continuous with the deep 

 fascia covering the abdominal muscles, and, at the lower 

 border of the pectoralis major muscle, it is continuous with 

 the axillary fascia. At the delto-pectoral triangle a process 

 from its deep surface dips in, between the deltoid and 

 pectoralis major muscles, to join the costo-coracoid membrane, 

 whilst, further laterally, it becomes continuous with the fascia 

 covering the deltoid muscle. The costo-coracoid membrane 

 will be described later (p. 24). 



Fascia Axillaris. The axillary fascia is a dense felted 

 membrane which extends across the base of the axilla. It 

 is continuous anteriorly with the deep fascia over the 

 pectoralis major, posteriorly with the fascial sheaths of the 

 latissimus dorsi and the teres major muscles, medially with 

 the deep fascia on the surface of the serratus anterior, 

 whilst laterally it is continuous with the deep fascia on 

 the medial surface of the proximal part of the arm. It is 

 drawn up towards the hollow of the axilla, and the 

 elevation is due chiefly to the connection of its deep surface 

 with the fascial sheath of the pectoralis minor, and partly 

 to its attachment to the areolar tissue which fills the axillary 



