While at the fornix and its neighborhood simple vascular loops supply the papillte, at the ostium vaginm, and especially over the columna rugs rum, the compound papillm are supplied by an anastomosing c,apillary plexus, which springs from the submucosa by fairly strong branches. In the middle of this net-work the veins arise. In the columns these latter vessels are numerous and large, and arranged in plexuses, and especially at the lower portions of the columns they give the tissue a cavernous appearance. The veins which collect the blood from the mucous mem brane form elong-ated meshes in the submucosa parallel to the longitudinal axis of the vagina. They unite into larger branches in the muscularis, and form in the connective tissue between vagina, urethra, bladder and rectum the so-called plexus venosus vaginalis. Many veins from the bul bus vestibuli enter the plexus in its anterior part; while its posterior di vision is gained by those labial veins which do not join the pudendal. In the posterior vaginal wall, alongside the art. vagin. run two fairly large veins, which receive the blood of the plexus; they empty into the plexus hemorrhoidalis.
Gnssenbauer does indeed find that the structure of this plexus ven. vag. is similar to that of the cavernous erectile organs; but the vaginal vessels, when full, never attain that degree of stiffness which the vestibu lar structures do, resembling rather, as Henle puts it, a filled sponge which can easily be emptied by pressure.
We know but little concerning the minute ramification of the vaginal lymphatic system. The nerves come from the sympathetic and the pu dendal plexus. Isolated groups of ganglion cells are found where two or more mednllated fibres come together. (Klein.) Their mode of termi nation in the human subject is not known. In rabbits and dogs Chrsch tschonowitsch' traced them as delicate non-medullated fibres accompany ing the vessels and forming a sub-epithelial net-work. From this plexus the finest fibres penetrated the deeper layers of the epithelium, and formed a mesh of nerve-fibres surrounding the epithelial cells, among which larger branched bodies were found, analogous to the Langerhans bodies of the rete Malphigi. In general the sensibility of the human vagina, is but small. Even,in the neighborhood of the introitus, operations can be done without narcosis. There are, however, exceptions; and the vagina may be the seat of violent neuralgias.
The connections of the vagina are most intimate at the entrance. The lower portion of the anterior wall is closely bound to the urethra, and the lower part of the posterior wall is attached to the perineum. Further up the connective-tissue union with the bladder, rectum, and the liga mentum latum is looser. Since the peritoneum of Douglas's oil-de-Ric covers a part of the upper posterior wall, we can divide the hinder vaginal surface into an upper peritoneal, a median rectal, and a lower perinea' portion. The anterior wall may be said to consist of a lower urethml, and an upper vesical part. The lateral portions of the vaginal vault are, corresponding to the base of the ligament= Mum, partially covered with peritoneum.
According to Luschka,' the ureters must not be forgotten here; in spite of their convergence, their vesical mouths are still an inch apart. The lateral portions of the vagina are covered by the vascular connective tis sue, which is supported by the diaphragma pelvis. Both this tissue and the connective tissue surrounding the lower posterior portion of the vagina contain much fat, which forms an elastic cushion for the vaginal walls.
(Kiwisch.) These connections make plain the fact that the organ in question must be subject to many changes of position and axis. This is not only the case during conception and childbirth, though the dilatation and dis location they may cause may be very considerable. A distended bladder and rectum may change the direction, shape, and length of the vagina. This will be plain from the sections shown in Figs. 9 and 10. If in spite of these variations the general position and shape of the vagina is main tained, it is due to the elasticity and tonna of the stretched recto- and vesico-vaginal septa, and to the integrity of the suspensory and support ing structures. So long as the ligamentous connections between pelvis, bladder, uterus, and rectum (lig. vesicalia, pubo-vesico-uterina, recto uterina, recto-sacralia) remain tense, and the peritoneal covering of the posterior and lateral vault is intact, the vagina will be sustained by its connections with other organs. The best supported of all is the anterior division of the anterior wall; it is attached to the urethra by the pelvic connective tissue. The posterior vesical portion rests upon the posterior wall; and the posterior wall rests with its supra-perineal portion upon the rectum, while its perineal portion rests upon the structures of the peri neum. Clinical experience teaches us that the muscular floor of the pelvis plays an important part in sustaining the vagina; but the subject has not been examined into anatomically.' There may be very considerable variations within normal limits in adults. I will only mention congenital shortness of the vagina, always combined with prolapse and retroversion of the uterus. In another place we will consider the variations in length and breadth, which are dependent upon age. In children the conditions of later fcetal life persist for a long time. When senile involution of the genitals occurs, the vagina shrinks in length and breaAlth, especially in the vault, and the atrophied mucous membrane becomes smooth and pale.
Nor are the disturbances caused by gravidity of less moment. The general hyperplastic development of the part causes increase in size and in laxity of texture. The participation of the muscularis in the process can be not only anatomic,ally but also functionally proven in the vagime of advanced pregnancy. We often feei contractions when examining women pregnant for the first time, especially of the crescent-shaped folds of the anterior wall; at other places they are not so plain, and are only noticeable during delivery, when the vagina has not been over-dilat,ed, nor has lost contractility from too long-continued pressure of the fcetal head. The peri-vaginal connective tissue is also greatly loosened in preg nancy; its fat disappears (Kiwisch) and its vessels dilate."These change,s enable the vagina to undergo the enormous dilatation, the traumatisma and displacements to which it is inevitably subjected during delivery. The greatest amount of longitudinal stretching during delivery occurs in the posterior wall; hence the frequent ruptures in this situation. We can appreciate even at the beginning of labor the fact that the posterior vaginal cul-de-sac ascends, sometimes even to the height of the middle of the pubis, while before it was at the level of the tuberosities of the ischia. As the head descends into the vagina, the ant,erior wall also descends, but the posterior wall remains higher up, and is therefore more tense.