1324 THE URO-GENITAL SYSTEM. 



Within the tunica mucosa are to be found small collections, or nodules, of lymph- 

 tissue. 



The vaginal wall is surrounded by a layer of loose vascular connective tissue containing 

 numerous large communicating veins. 



Vessels and Nerves of the Vagina. The blood -supply of the vagina is for the most part 

 derived from the vaginal artery, the vaginal branch of the uterine artery, the vaginal branches 

 of the middle haemorrhoidal artery, and from the branches of the internal pudendal. The veins 

 form a plexus surrounding the vaginal wall, and drain their blood into the tributaries of the 

 hypogastric. 



The lymph- vessels from the upper part of the vagina join the hypogastric group of glands, 

 while those from the lower part end in the superficial inguinal glands. 



The nerves of the vagina are derived from the plexus uterovaginalis and from the plexus 

 vesicalis. Other fibres are derived directly from the third and fourth sacral nerves. 



THE FEMALE EXTERNAL GENITAL ORGANS. 

 (PUDENDUM MULIEBRE.) 



The term pudendum muliebre, or vulva, is applied collectively to the female 

 external genital organs, i.e. to the labia majora and the structures which lie 

 between them. 



Labia Majora. The labia majora represent the scrotum in the male, and form 

 the largest part of the female external genital organs. They form the boundaries, 

 on each side, of the rima pudendi or uro-genital cleft, into which the urethra and 

 vagina open. Each labium is a prominent rounded fold of skin, narrow behind 

 where it approaches the anus, but increasing in size as it passes forwards and 

 upwards to end in a median elevation, the commissura labiorum anterior, or the mons 

 pubis or Veneris. The mons Veneris lies over the symphysis pubis, and, like the 

 labia majora, it is composed chiefly of fatty and areolar tissue, and is covered with 

 hair. The lateral convex surface of each labium majus is covered by skin con- 

 taining numerous sebaceous glands and resembling that of the scrotum in the male, 

 but the medial, flatter surface is smooth, and presents a more delicate integumentary 

 covering. In some cases the posterior narrow ends of the labia majora are 

 connected across the middle line, in front of the anus, by a slight transverse fold 

 the commissura labiorum posterior or posterior commissure. 



Usually, especially in young adult subjects, the labia majora are the only visible 

 parts of the external genital organs, since they are in contact with one another, 

 and completely enclose the structures within the rima -pudendi. 



The round ligament of the uterus ends in the fatty tissue of the labium majus. 

 The superficial subcutaneous tissue resembles that of the scrotum, but contains no 

 muscular fibres. 



The nerve-supply corresponds with that of the scrotum, the anterior part of each labium being 

 supplied by the branches of the ilio-inguinal nerve, and the posterior part by branches from the 

 internal pudendal and by the perineal branch from the posterior cutaneous nerve of the thigh. 

 The blood-vessels of the labia majora are derived from the external pudendal arteries and from 

 the perineal branches of the internal pudendal vessels. 



Labia Minora. The labia minora pudendi (O.T. nymph) are a pair of much 

 smaller and narrower longitudinal folds, usually completely enclosed within the 

 cleft between the labia majora. Diminishing in size, and becoming less marked 

 in their posterior parts, the labia minora end by gradually joining the medial 

 surfaces of the labia majora. In the young subject, a slightly raised transverse 

 fold is usually seen connecting the posterior ends of the labia minora ; to this 

 fold the term frenulum labiorum pudendi (O.T. fourchette) is applied. Traced 

 forwards, each labium minus divides into two portions, a lateral and a medial. 

 The lateral portions of the two labia unite over the glans clitoridis, and 

 form for it a fold or covering called the praeputium clitoridis. The medial 

 portions, uniting at an acute angle, join the glans and form the frenulum clitoridis. 

 The skin of the labia minora resembles the integument on the medial or deep 

 surface of the labia majora, being smooth, moist, and pink in colour. The medial 

 surfaces of the labia minora are in contact with one another ; their lateral surfaces 

 are applied against the medial aspects of the labia majora. 



