1168 FEMALE GENERATIVE ORGANS. 



distance from the os, its attachment extending higher up on the posterior than on 

 the anterior wall of the uterus. 



Relations. Its anterior surface is in relation with the base of the bladder and 

 with the urethra. Its posterior surface is connected for the lower three-fourths of 

 its extent to the anterior wall of the rectum, the upper fourth being separated from 

 that tube by the recto-vaginal fold of peritoneum, which forms a cul-de-sac between 

 the vagina and rectum. Its sides give attachment superiorly to the broad ligaments, 

 and inferiorly to the Levatores ani muscles and recto-vesical fascia. 



Structure. The vagina consists of an internal mucous lining, of a muscular 

 coat, and between the two of a layer of erectile tissue. 



The mucous membrane is continuous above with that lining the uterus. Its 

 inner surface presents, along the anterior arid posterior walls, a longitudinal ridge 

 or raphe, called the columns of the vagina, and numerous transverse ridges or 

 rugae, extending outward from the raphe on either side. These rugae are divided 

 by furrows of variable depth, giving to the mucous membrane the appearance of 

 being studded over with conical projections. There are also microscopic papillae ; 

 the projections are most numerous near the orifice of the vagina, especially in 

 females before parturition. The epithelium covering the mucous membrane is of 

 the squamous variety. The submucous tissue is very loose and contains numerous 

 large veins, which by their anastomoses form a plexus, together with smooth muscular 

 fibres derived from the muscular coat ; it is regarded by Gussenbauer as an erectile 

 tissue. It contains a number of mucous crypts, but no true glands. 



The muscular coat consists of two layers : an external longitudinal, which is 

 far the stronger, and an internal circular layer. The longitudinal fibres are 

 continuous with the superficial muscular fibres of the uterus. The strongest 

 fasciculi are those attached to the recto-vesical fascia on each side. The two layers 

 are not distinctly separable from each other, but are connected by oblique decus- 

 sating fasciculi which pass from the one layer to the other. In addition to this 

 the vagina at its lower end is surrounded by a band of striped muscular fibres, the 

 sphincter vagina? (see page 464). 



External to the muscular coat is a layer of connective tissue containing a 

 large plexus of blood-vessels. 



The erectile tissue consists of a layer of loose connective tissue situated between 

 the mucous membrane and the muscular coat; imbedded in it is a plexus of large 

 veins, and numerous bundles of unstriped muscular fibres derived from the circular 

 muscular layer. The arrangement of the veins is similar to that found in other 

 erectile tissues. 



THE UTEEUS. 



The Uterus is the organ of gestation, receiving the fecundated ovum in its cavity, 

 retaining and supporting it during the development of the foetus, and becoming 

 the principal agent in its expulsion at the time of parturition. 



In the virgin state it is pear-shaped, flattened from before backward, and 

 situated in the cavity of the pelvis between the bladder and the rectum ; it is 

 retained in its position by the round and broad ligaments on each side, and projects 

 into the upper end of the vagina below. Its upper end, or base, is directed 

 upward and forward ; its lower end, or apex, downward and backward, in the 

 line of the axis of the inlet of the pelvis. It therefore forms an angle with the 

 vagina, since the direction of the vagina corresponds to the axis of the cavity and 

 outlet of the pelvis. The uterus measures about three inches in length, two in 

 breadth at its upper part, and nearly an inch in thickness, and it weighs from an 

 ounce to an ounce and a half. 



It consists of two parts : (1) the body, with its upper broad extremity, the 

 fundus ; and (2) the cervix, or neck, which is partly above the vagina and partly 

 in the vagina. The fundus is placed on a line below the level of the brim of the 

 pelvis, being directed forward behind the upper portion of the anterior pelvie 

 wall. 



