550 MANUAL OF HISTOLOGY. 



280. 



The vagina, an elastic tube, is to a certain extent a continuation, as far 

 as structure goes, of the generative organs situated higher up. In it we 

 find a layer of muscular fibres internal to a thick envelope of connective- 

 tissue, loose without and dense within, and containing numerous elastic 

 elements. This muscular coat consists of a layer of longitudinal fibres 

 internally, and another of circular fasciculi externally. The mucous 

 membrane of the part presents ridges and protuberances which go by the 

 name of columnar rugarum, besides which it is possessed of numerous 

 papillae, similar to those of the cervix uteri, lying underneath its flattened 

 epithelium. It appears to be quite destitute of mucous glands, and its secre- 

 tions have an acid reaction. 



The hymen is nothing but a duplicature of mucous membrane rich in 

 nerves and vessels. 



The vascular system of the vaginal wall has a different arrangement for 

 each of the three layers of the latter, and is remarkable for the high 

 degree of development of the venous networks. But little is known, on 

 the other hand, of the lymphatics of the part, but scattered lymphoid 

 follicles have been met with in the vaginal mucous membrane of both 

 man and the mammalia, and considerable patches have been observed to 

 present an infiltration with lymph-cells. The nerves by which it is sup- 

 plied are derived from the sympathetic and plexus pudendus. In man 

 their termination in papillae has not been recognised, although their fibres 

 are seen to divide ; but in the rabbit the vaginal tunics are supplied with 

 terminal bulbs and Pacinian bodies (Krause). See p. 333. 



The external female genitals consist of the clitoris and lalia major a 

 and minora. 



The clitoris is possessed of a prepuce or fold of mucous membrane 

 continuous with that covering the glans, in which situation it is supplied 

 with numerous papillae. Its corpora cavernosa and bulbi vestibuli are 

 analogous to the cavernous portions of the male organ (see below). 



The labia minora, or nymphce, are also small duplicatures of mucous 

 membrane. They present numerous papillae and very vascular connective- 

 tissue without any fat cells. In them, as in the external parts of genera- 

 tion, numerous sebaceous glands, without hairs, are to be found. 



The labia majora folds of skin padded with fat present on their 

 internal surface all the characters of a mucous membrane, while externally 

 their structure is that of the skin. On their outer surface they are 

 covered with hairs, into whose follicles numbers cf sebaceous glands pour 

 out their secretions. 



The vestibulum and opening of the vagina contains many ordinary 

 racemose mucous glands, of which the largest, attaining a diameter of 

 15 mm. are known as the glands oiBartholin ofDuverney, which open with 

 tolerably long excretory ducts into the vestibule. They correspond to 

 Cowper's glands in the male generative apparatus. They are lined with 

 low columnar epithelial cells, and filled with a transparent mucoid secre- 

 tion of viscid consistence. 



The Hood-vessels of the part, with the exception of those of the corpora 

 cavernosa have nothing remarkable about them. The lymphatics require 

 closer study, as also the nerves which spring from the plexus pudendus of 

 the sympathetic. The latter are stated by Koelliker to terminate in 

 certain papillae of the clitoris in a manner similar to their arrangement in 



