PRELIMINARY REMARKS UPON THE ANATOMICAL AND PHYSIOLOGICAL PECULIARITIES OF THE FEMALE URE THRA AND BLADDER.
Its anterior extremity is .4 of an inch below the symphysis; it is kept in place by the ligamentum pubo-vesicale medium, which fills the space between the urethra, the ligamentum arena tum, and the rami of the clitoris. The urethral wall is tough, and about ith of an inch thick; the septum becomes thicker at those spots at which it is united to the vagina. Its mucous membrane possesses, according to Robin and Cadiat, more elastic fibres than any other in the body. Its lowest part is lined with stratified pavement epithelium, like that of the vagina; while the epithelium of its upper part resembles that of the bladder. Oberdieck, however, found in three out of four cases a single layer of cylindrical epithelium, consisting of long prismatic cells, between whose pointed lower ends small round cells were scattered. Besides this the urethra shows longitudinal folds, vascular papillte, and among the numerous lacunw near the external orifice various projections, especially in pregnant and puerperal women.
To Prof. Skene (see page 5) is due the credit of having specially described the two chief lacunm near the orificiurn urethra3 externum; he considers them glandular, and found concretions in them. But Ober dieck and Schuller claim that they possess no real glandular epithelium. Koeks declares them to be simply Gartner's canals; but this has been dis proved by Dohrn, Oberdieck, Rieder, and Schuller. The latter calls them urethral passages. He found them most developed in pregnant women, being short and narrow in children and those who had reached the climacteric. Their orifices are about one twenty-fifth of an inch in diameter; they then enlarge, dip deeper down into the tissues than do the ordinary lacunm of the urethra, and run upwards along the walls of that channel. They are about inches in length, though a probe can only be inserted to the depth of about one inch. As they go upwards they subdivide until eventually there are seven to eight epithelial-lined tubes present. The ultimate tubes lie in the circular muscle of the urethra, being sometimes among its outermost fibres. Their diameter
before division is about one line; in children it is half a line. The epi thelium is transitional, and is easily distinguishable from the single or double layered and occasionally ciliated cylindrical epithelium of Gart ner's canals.
The remaining urethral lacunw are irregular in number, symmetry, and position. Sometimes several of them open into a pocket, which may be large enongh to entangle the point of a catheter (Oberdieck). At their blind end the epithelium is in single layers and cylindrical; it then becomes stratified cylindrical, and near their mouth becomes pave ment.
Besides this the mucosa contains a multitude of small mucous glands, which in elderly persons often contain small black particles, similar to the prostatic concretions.
Below the MUCOS21 is a submucous elastic network, into which the ends of the above-mentioned glands project, surrounded by a network of min ute veins. External to the submucosa is a layer which varies in thick ness at various periods of life, and is composed of a longitudinal and a circular layer of muscular fibres, united by connective and cavernous tis sue. It is the corpus sponqiosum urethrm. Dr. liffelmann found, be sides the organic circular muscular layer a layer of voluntary fibres lying outside it, and composed of transverse and longitudinal portions. The transverse are innermost, and form the voluntary or outer sphincter of the bladder. They form a complete ring from the bladder end of the ure thra to its middle. This discovery explains the fact that, when injuries to the urethra reach of an inch from the external orifice, continence of urine may be attained by operative union. Luschka claims also to have discovered an especial sphincter urethra3 et vaginoe, which is ring-shaped, flat, and situated immediately behind the bulbi vestibulw; it is I to i of an inch broad, and surrounds not only the introitus vaginEe and urethra but closes the latter by compressing it against the septum urethro-vagi nale. Bordering on the cavernous venous plexus surrounding the ure thra, it inosculates with the anterior end of the transversus profundus muscle.