The nerves that supply the kidneys are derived from the semliunar ganglion, noticed in describing the liver ; they lorm a plexus round the trunks of the vessels. The lymphatics arc chiefly deep seated, or at least the superficial absorbents are very small. They may be distinctly seen in the lett kidney in the Figure of Plate XX.
The ureters run obliquely sacrad in a serpentine direction, on each side of the lumbar vertebra;, till they reach the dorsal side of the urinary bladder, into which they enter, as will be presently described. They are membranous tubes, resembling in structure the biliary ducts, but not like them regularly cylindrical ; the ureters being alternately contracted and dilated. Besides the peripheral and central coats, common to all excretory ducts, the ureters are sant to possess a middle muscular coat, and on their sternal sides they receive a fold from the peritoneum.
Following the course of the ureters, we are led to the general receptacle of the urine, or urinary bladder. This is situated in the sacral and sternal part of the pelvis, between the pubis and the rectum in men, and between the pubis and vagina in women. In man, the bladder, when distended, is nearly of a spherical form, a little flattened sternad, convex dorsad, and laterad, and of a greater diameter from side to side, than from its sternal to its dorsal part. It is commonly divided into fundus, on that part which is most (Wawa!, and which, in the natuarl state, projects a little sttrnad ; neck, which is its most sacral, or depending part, though this is scarcely so much contracted as to deserve the title of neck ; and body lying between these. .•11antad and partly dorsad, the bladder is connected with the peri toneum, and is attached to the rectum and to the sides of the pelvis, partly by that membrane, and partly by cel lular substance. It is connected with the navel by a triple ligamentous cord, to the arch of the pubis by a ligamentous expansion, running from each side of its neck, and to the kidneys by the ureters.
The bladder is composed of three distinct coats, each of considerable thickness ; a peripheral coat, partly derived lroni the peritoneum, and partly from the adja cent cellular substance, a central mucous membrane, similar to the other membranes of that class, and an in termediate fibrous coat, which is evidently muscular.
The fleshy fibres composing this coat run in various directions, collected into numerous separate bundles, but many of them are longitudinal, and converge from the body of the bladder to its neck, where they compose a layer, much thicker than any other part of the bladder, forming what has been called the sphincter of the urin ary bladder. This muscle, or coat, is connected with the others by cellular substance.
At its sacral part the bladder is perforated by three orifices, one sternad terminating its neck, and leading to the membranous tube that runs through the penis, called the urethra, and two laterad and dorsad, of nearly an oval form, which are the openings of the ureters. These excretory ducts coming from the kidneys, having reached the clorsal part of the bladder, enter obliquely between the muscular coat and mucous membrane, and run for some distance between these coats, till they per {orate the mucous membrane by the openings just de s cribed.
The arteries that supply the urinary bladder conic from the hypogastric, and have nothing exuaort.in..ry in their appearance ; but the veins are rt_marhabie tor forming a very complicated network, c specially about the neck of the bladder. This receptacle is turnished ith numerous lymphatics, and \vitt' nervous filaments coming from the hypogast•ic plexus.
The urinary bladder is possessed of considerable 1)0\1't ; is very expansible and elastic, and, cially about its neck, extremely sensible.
The bladder of women is broader than that of men. has not so long a neck, and its lief k is not surrounded with any thing like the male prostate gland.
The neck of the bladder, and commencement of the urethra, are surrounded by a glandular body that pro jects considerably dorsad, and is called the lrostatc gland, and from this gland dorsad and a little latcrad, there extend over the body of the bladder two tortuous lobated bodies, which are called seminal vesicle (vevi culx seminales.) As these appendages to the bladder seem, however, to belong rather to the organs of repro duction, we shall defer their description till we consider those organs.