550 MAMMARY GLANDS. 



The rupture of the hymen or its rudimentary existence, gives rise 

 to the appearance of a fringe of papillae around the opening of the 

 vagina : these are called caruncu/cs myrtifarmes. 



The triangular smooth surface between the clitoris and the en- 

 trance of the vagina, which is bounded on each side by the upper 

 portions of the nymphae, is the vestibule. 



At the upper angle of the vagina is an elevation formed by the 

 projection of the upper wall of the canal, and analogous to the bulb 

 of the urethra of the male : and immediately in front of this tubercle, 

 and surrounded by it, is the opening of the urethra, the meatus 

 urinarius. 



MAMMARY GLANDS. 



The Mammce are situated in the pectoral region; and are separated 

 from the pectoralis major muscle by a thin layer of superficial fascia. 

 They exist in the male as well as in the female, but in a rudimentary 

 state, unless excited into growth by some peculiar action, such as 

 the loss or atrophy of the testes. 



Their base is somewhat elliptical, the long diameter correspond- 

 ing with the direction of the fibres of the pectoralis major muscle. 

 The left mamma is generally a little larger than the right. 



- Near the centre of the convexity of each mamma is a small pro- 

 jection of the integument, called the nipple, which is surrounded by 

 an areola having a coloured tint. In the female before impregna- 

 tion, the colour of the areola is a delicate pink ; after impregnation 

 it assumes a brownish hue which deepens in colour as pregnancy 

 advances; and after the birth of a child, the brownish tint continues 

 through life. 



The areola is furnished with a considerable number of sebaceous 

 follicles, which secrete a peculiar fatty substance for the protection 

 of the delicate integument around the nipple. During suckling these 

 follicles are very much increased in size, and have the appearance 

 of small pimples projecting from the skin. At this period they 

 serve by their increased secretion to defend the nipple and areola 

 from the excoriating action of the saliva of the infant. 



In Structure, the mamma is a conglomerate gland, and consists 

 of lobes, which are held together by a dense and firm cellular tissue; 

 the lobes are composed of lobules; and the lobules, of minute csecal 

 vesicles, the ultimate terminations of the excretory ducts. 



The excretory ducts (tubuli lactiferi), from ten to fifteen in 

 number, commence by small openings at the apex of the nipple, 

 and pass inwards, parallel with each other, towards the central 

 part of the gland, where they form dilatations (ampullae) and give 

 off numerous branches to ramify through the gland to their ultimate 

 terminations in the minute lobules. 



The ducts and csecal vesicles are lined throughout by a mucous 

 membrane, which is continuous at the apex of the nipple with the 

 integument. - 



