Female Organs of Generation. 



81 



421. The Right Mammary Gland during Lactation. 



2 / 3 natural size. 



The mammary glands or Mammae lie upon the Pectoralis major 

 muscle, between the third and sixth ribs ; they are separated from each other 

 by the bosom, Sinus. They are hemispherical eminences, presenting just 

 below the center a small conical prominence, the nipple, Papilla s. 

 Mamilla. The nipple is surrounded by the a r e o 1 a, which has a colored 

 tint and is covered with numerous tubercles ; at the tip of the nipple the 

 excretory ducts of the mammae open, at the surface of the 

 areola, the Glandulae lactiferae aberrantes. The mamma is formed of from 

 16 24 lobes held together by fibrous or areolar tissue, and having adi- 

 pose tissue penetrating between them ; each lobe is composed of a number 

 of smaller lobes, and these again of smaller and smaller lobules ; the smallest 

 lobules consist of a cluster of rounded vesicles, which open into the smal- 

 lest branches of the lactiferous ducts. The excretory ducts of the lobules 

 unite to form a larger Ductus lactiferus s. galactopliorus, of which each 

 corresponds to one of the lobes. These ducts converge towards the areola, 

 beneath which they become considerably dilated, especially during lactation, 

 so as to form sinuses, Sinus lactei ; then they again become reduced 

 in size, and proceed without communicating with each other, to the 

 summit of the nipple, where they open by separate orifices. 



Heitzmann, Atlas. II. 11 



