Since the vagina is the tubular duct of the uterus, and is formed with it from the Mtillerian ducts, the tissues and various layers of the two organs are directly continuous and of the same construction. The walls are thinnest in the upper part, being not over virth of an inch when empty of blood. Towards the orifice they become thicker. The anterior pillar of the columna rugarum is the stouter; it reaches to the introitus, when its projection beneath the orificium urethrae forms the carina vaginae (Kohlrausch), or the tubereulam vaginte (Luschka). The posterior column usually lies somewhat higher up. Irregular lateral bmnches spring from both columns, anastomosing at their extremities; hence the roughness of surface of the virgin vagina. For further details we must refer the reader to the anatomical text-books, and especially to Henle.
Cross sections of the vaginal wall show an internal and dense mucous coat, and an outer looser muscular coat, intimately connected with it. Around the latter is a connective-tissue envelope, in which the larger vessels and nerves ramify. (Membrane cellularis s. adventitia.) This latter coat is not of the same density throughout; in the recto-vaginal and vesico-vaginal septa it is looser, and in the former position it contains fat. The mucosa is provided in varying degree in different places with microscopic papillts; they are mostly simple, though on the columns and near the introitus they are compound. The mucosa consists essentially of a dense connective tissue, containing abundant elastic elements and deli cate bundles of muscular fibres. The vascular muscularis is formed of masses of smooth muscular fibres, bound together by a connective-tissuo framework.
According to the most recent authorities, the innermost muscular layer is longitudinal, while the external one runs in a, circular direction.' So far as I know, Luschka ' only is of a different opinion. I myself have ex amined a, number of preparations in conjunction with Professor Eppinger, and have always found the inner layer to be transversely and the external to be longitudinally arranged (Figs. 7 and 8), and Professor Told t has had the kindness to show me some preparations of his which show the same arrangement. But we saw the arrangement, described by the authorities, where the section fell exactly upon a columns, especially the anterior one. And not only does the arrangement, as we found it, conform to the general type of muscular layers surrounding passages, and especially to that of the uterus, but it better explains the circular vaginal contraction which we occasionally meet with clinic,ally. Toldt (L c.) has recently stated that
we can find in a general way an external dense layer of longitudinal fibres, and an inner non-continuous one which is mostly circular, but still it con tains longitudinal and oblique bundles of fibres.
Several layers of epithelial cella cover the mucous membrane, consisting of large, nucleated, angular cells. According to v. Preuschen z the deep est layers contain cylindric,a1 cells with elongated nuclei. The scanty mucus which normally covers the surface is sour in reaction; it is just sufficient to keep the surface moist, and contains no formed elements save epithelial cells. Foreign substances are, of course, often present, from the free access which atmospheric air may have to the part; and atnong these foreign subst,ances the lowest organisms are especially worthy of our attention. We will consider them elsewhere. V. Prenschen has described in the crypts of the mucosa of the upper vagina conglomerate glands, lined with ciliated epithelium. Most anatomists deny their exist ence, and they certainly occur exceptionally, if at all. Some recent ob servations, however, would seem to confirm the statement.' Gland-like crypts of the mucous membrane are common enough, and sometimes form. extensive blind passages, especially in the vicinity of the introitus and the extremities of the columns. It is doubtful whether the conglomerate glands which Henle saw in one case are not to be regarded as pathological appearances. Lymph follicles, similar in structure to the solitary glands of the small intestine, have been found by Lowenstein in the human vagina. Toldt and Chiari have also noticed lymph-follicle-like bodies im bedded in the mucosa.
The vagina gets its arterial blood chiefly from the vaginal arteries which run along its posterior wall. Their mode of origin is variable; usually they are branches of the uterine, hypogastric, internal pudendal, or hemorrhoidalis media arteries; but Farre ° has seen them arise from the obtura,tora As a rule two of them run down the posterior wall. In every case, however, branches of the pudendal and the vesical take part in the arterial supply of the vagina. According to Gussenbauer ' the art. vagin. is usually a fairly large branch of the hmmorrhoidalis media, and it runs in the median line from behind forwards in the posterior vaginal wall out side the muscular layer. As it runs it gives off branches which pass off at right angles to supply the lateral vaginal walls. These branches pierce the muscular layer obliquely, and, breaking up into a capillary network in the submucosa, send loops of vessels into the papilla3 of the mucous mem brane.