The arteries supplying the bladder are the superior and inferior vesical of the interior iliac, the latter of which is the larger, and supplies the more vascular floor. The veins have a plexiform arrangement in the various coats, and join the internal iliac. Those in the region of the trigone frequently become congested, and even varicose in old persons, especially in cases of enlarged prostate. The lymphatics run to the glands surrounding the iliac vessels. The motor nerves are derived from the eleventh and twelfth dorsal and first lumbar, which pass through the hypogastric, pelvic, and vesical plexuses, and the sensory nerves from the third and fourth sacral, which pass direct to the vesical plexus. The reflex micturition centre is situated in the lumbar enlargement, and is normally under control of the brain. In same spinal conditions this control is lost, and the centre acts automatically, emptying the bladder when necessary at regular intervals. When, on the other hand, the centre is destroyed, absolute incontinence results. The trigone is richly supplied by the vesical plexus, which also supplies the seminal vesicle, vas deferens, and distal extremity of the ureter. As the skin of scrotum, and penis, and mucous membrane of urethra are also supplied by these segments, bladder affections frequently cause pain referred to base of glans penis, etc.
The female bladder has a smaller capacity than that of the male. There being no prostate, the neck lies nearer the symphysis, and is very distensible, even permitting of a calculus becoming impacted in it. Indeed, stones of a diameter of 1 inch have been removed by forceps after dilatation of the urethra. Through the dilated urethra, also, the orifices of the ureters may be seen and examined. The bladder wall and vagina are intimately connected, and vesico - vaginal fistula frequently occur. The utero-vesical fold of peritoneum extends down only to the junction of body and cervix of the uterus; beyond that point the cervix is loosely adherent to the posterior layer of the bladder, and the vagina intimately so.
Associated with defect in the anterior abdominal wall, the anterior wall of the bladder may be absent, the posterior wall and trigone presenting as a red vascular mass. This condition is called ectopia vesica, or extroversion of the bladder. Hernia of the bladder may occur through the femoral or inguinal canals, and also through the obturator and great sacro-sciatic foramina. Prolapse of the bladder backwards into the vagina is called vaginal cystocele, and into the rectum rectal cystocele. Rupture of the bladder, caused by blows or falls when the bladder is distended, generally occurs at the upper and posterior surface, which, being covered by peritoneum, causes invasion of the peritoneal cavity. The bladder may, however, be wounded, frequently about the base, and therefore extraperitoneally, by a fractured pelvis, while it has also been wounded through the sciatic notch, thyroid foramen, rectum, abdomen, etc. Fistula may connect the bladder with the rectum, colon, or vagina (a bi-mucous fistula), or with the suprapubic region, or perineum (muco-cutaneous fistulas). Where the bladder communicates with the bowel, flatus and even faecal matter may be passed per urethram. Stones in the bladder frequently rest upon the vascular and sensitive trigone, causing pain and haemorrhage, but sometimes they become arrested in one of the pockets of mucous membrane. Tumours, such as papilloma or epithelioma, and ulcerative processes, such as tubercle, frequently occur in the region of the trigone. Most of these conditions become complicated sooner or later by cystitis, or inflammation of the bladder wall. In order to treat such conditions it is frequently necessary to open the bladder. Cystotomy is generally performed suprapubically, a vertical incision being made immediately above the pubes, after the bladder has been distended, so as to raise the peritoneum. The superficial tissues are cut, recti and pyramidales separated, transversalis fascia divided, prevesical fat pushed aside, and the bladder exposed and treated. The bladder may also be reached through the perineum, vagina, or rectum, but the latter route is seldom employed, and is dangerous. Stones are sometimes extracted entire per urethram in the female, and in the male by previous crushing (lithotrity) and washing out through a large catheter (litholopaxy).