75G FEMALE ORGANS OF GENERATION. 



MAMMARY GLANDS. 



The Mammse or breasts are accessory glands of the generative system, which 

 secrete the milk. They exist in the male as well as in the female ; but in the 

 former only in a rudimentary state, unless their growth is excited by peculiar 

 circumstances. They are two large hemispherical eminences, situated towards 

 the lateral aspect of the pectoral region, corresponding to the interval between 

 the third and sixth or seventh ribs, and extending from the side of the sternum 

 to the axilla. Their weight and dimensions differ at different periods of life, and 

 in different individuals. Before puberty they are of small size, but enlarge as 

 the generative organs become more completely developed. They increase during 

 pregnancy, and especially after delivery, and become atrophied in old age. The 

 left mamma is generally a little larger than the right. Their base is nearly 

 circular, flattened or slightly concave, and having their long diameter directed 

 upwards and outwards towards the axilla ; they are separated from the Pectoral 

 muscles by a thin layer of superficial fascia. The outer surface of the mamma is 

 convex, and presents, just below the centre, a small conical prominence, the 

 mammilla or nipple. The surface of the nipple is dark-colored, and surrounded 

 by an areola having a colored tint. In the virgin, the areola is of a delicate 

 rosy hue ; about the second month of impregnation, it enlarges, and acquires a 

 darker tinge, which increases as pregnancy advances, becoming, in some cases, 

 a dark brown or even black color. This color diminishes as soon as lactation 

 is over, but is never entirely lost through life. These changes in the color of the 

 areola are of extreme importance in forming a conclusion in a case of suspected 

 pregnancy. 



The nipple is a cylindrical or conical eminence, capable of undergoing a sort of 

 erection from mechanical excitement. It is of a pink or brownish hue, its surface 

 wrinkled and provided with papillas, and its summit perforated by numerous 

 orifices, the apertures of the lactiferous ducts. Near the base of the nipple, and 

 upon the surface of the areola, are numerous sebaceous glands, which become much 

 enlarged during lactation, and present the appearance of small tubercles beneath 

 the skin. These glands secrete a peculiar fatty substance, which serves as a pro- 

 tection to the integument of the nipple in the act of sucking. The nipple consists 

 of numerous vessels, which form a kind of erectile tissue, intermixed with plain 

 muscular fibres. 



Structure. The mamma consists of gland tissue ; of fibrous tissue, connecting 

 its lobes ; and of fatty tissue in the intervals between the lobes. The mammary 

 gland, free from cellular tissue and fat, is of a pale reddish color, firm in texture, 

 circular in form, flattened from before backwards, thicker in the centre than at 

 the circumference, and presenting several inequalities on its surface, especially in 

 front. It consists of numerous lobes, and these are composed of lobules, connected 

 together by areolar tissue, bloodvessels, and ducts. The smallest lobules consist 

 of a cluster of rounded vesicles, which open into the smallest branches of the 

 lactiferous ducts ; these ducts, uniting, form larger ducts, which terminate in a 

 single canal, corresponding with one of the chief subdivisions of the gland. The 

 number of excretory ducts vcrries from fifteen to twenty ; they are termed the 

 tubuli lactiferi sen galactophori. They converge towards the areola, beneath which 

 they form dilatations or ampullae, which serve as reservoirs for the rnilk, and, at 

 the base of the nipple, become contracted, and pursue a straight course to its 

 summit, perforating it by separate orifices considerably narrower than the ducts 

 themselves. The ducts are composed of areolar tissue, with longitudinal and 

 transverse elastic fibres, and longitudinal muscular fibres; their mucous lining is 

 continuous, at the point of the nipple, with the integument; its epithelial lining is 

 of the tessellated or scaly variety. 



The fibrous tissue invests the entire surface of the breast, and sends down septa 

 between its lobes, connecting them together. 



