NORMAL HISTOLOGY. 



The deepest part of the mucosa is continuous with the loosely- 

 woven, highly-vascular submucous tissue ; outside the latter follows 

 the muscular tunic, composed of an inner circular and an outer 

 longitudinal stratum of involuntary muscle. These layers are not 

 sharply defined, but are blended with one another by numerous 

 oblique bundles. The outer adventitious coat consists of a dense 

 fibrous tunic, rich in elastic tissue, which contributes greatly to the 

 strength of the vaginal walls : this fibrous coat is best developed in 

 the anterior wall of the canal, where it closely unites the vagina to the 

 bladder, and encloses within its firm, compact mass the urethra. 



The blood-vessels of the vagina are very numerous ; the larger 

 twigs break up within the submucous tissue into smaller vessels, 

 which pass to supply the muscular coat and the mucous membrane. 

 Those entering the latter terminate in capillary loops lying beneath 

 the epithelium and within the papillae. The veins correspond with 

 the larger arteries, but, in addition, form dense plexiform net- 

 works beneath the serous coat. Around the entrance of the vagina 

 the number and size of the venous channels give the submucous 

 coat the character of cavernous tissue. 



The lymphatics form net-works within the mucosa and muscularis, 

 which unite with the larger lymph-channels within the adventitia. 



The nerves supplying the vagina, derived from the hypogastric 

 plexus and from the sacral and pudic nerves, consist of both pale 

 and medullated fibres. Numerous microscopic ganglia occur in con- 

 nection with the sympathetic fibres. Special end-bulbs, or the 

 genital corpuscles of Krause, exist within the vaginal mucosa. 



THE GENITALIA. 



The labia majora consist of the folded integument enclosing an 

 abundance of adipose tissue, together with blood-vessels, nerves, 

 glands, and bundles of involuntary muscle ; their outer surface 

 corresponds to the usual integument of the vicinity, while internally 

 they assume partly the character of the adjacent mucous membrane. 

 The median surfaces of the labia contain little fat, but, on the 

 other hand, many bundles of elastic and unstriped muscular tissue. 

 Sebaceous follicles and sweat-glands are numerous, but they 

 are more plentiful on the outer than on the inner surface of the labia. 

 Owing to the unusual quantity of pigment contained within the 

 deeper layers of the epithelium, the labial integument is especially 

 dark. 



The labia minora, or nymphae, include between their folds of 

 mucous membrane vascular areolar tissue ; their external surfaces 

 resemble somewhat in appearance the adjoining integument of 

 the external labia, with which they are continuous. Vascular 



