The Urinary Tract
The abdominal ureter is a muscular tube, approximately 25 cm long and 5 mm wide, extending from a slight constriction at its junction with the pelvis of the kidney and descending vertically in a line parallel with the tips of the lumbar transverse processes to the midpoint of the ureter. This midpoint lies at the origin of the external iliac artery, where the ureter then enters the lesser pelvis. The blood supply of the ureter includes small branches from the renal and ovarian arteries, as well as the aorta and the common, internal iliac, uterine, and superior vesical arteries. These branches form longitudinal anastomoses that lie on the surface of the ureter. Because of this anastomotic network, branches can be divided without interfering with the blood supply.
The pelvic ureter runs posteroinferiorly anterior to the internal iliac artery and deep to the peritoneum of the lateral wall of the pelvis (Fig. 1.).
It travels along the lateral fornix of the vagina inferior to the broad ligament and uterine artery turning superiorly into the broad ligament. It enters the bladder wall to open into the superolateral angle of the trigone of the bladder.
(Fig 1.) Innervation of uterus, bladder, and vagina, viewed from the perineum. 1, Inferior vesical nerves; 2, superior vesical nerves; 3, uterine artery; 4, uterine plexus (uterovaginal); 5, plexus pelvinus (pelvic ganglion, inferior hypogastric plexus); 6, pelvic nerves (parasympathetic); 7, superior hypogastric plexus (sympathetic); 8, vaginal ramus; 9, uterine nerves; 10, vagina; 11, uterus; 12, ureter; 13, urinary bladder.
The internal surface of the bladder is ridged by folds of mucous membrane, whereas on the posterior wall there is a smooth triangular area previously mentioned as the trigone of the bladder. The median internal urethral orifice is located at the inferior angle of the triangle. Fibrous bundles between the anteroinferior part of the pubic symphysis and the urethra represent the pubourethral ligament, which stabilizes the urethra and forms the inferior boundary of the retropubic space.