Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

Urinary BladderThe urinary bladder is a hollow muscular organ which serves as a reservoir for urine. It lies in thepelvis behind the pubic bone. The adult urinary bladder has a capacity of 300-350 milliliters.Three openings mark off a triangular area called the trigone at the base of the bladder. These arethe orifices of the two ureters and the urethra. The trigone is smooth even when the bladder isempty; the remainder of the bladder wall is in folds allowing for expansion when the bladder is full.The superior surface of the bladder may be referred to as the dome; other subsites are the lateral,anterior, and posterior walls. The trigone may also be referred to as the floor or base.In the female, the bladder is located in front of and below the uterus being separated from theanterior part of the uterus by a fold of peritoneum called the uterovesical pouch. Posteriorly, it isconnected to the cervix and upper vagina by a thick layer of connective tissue.In the male, the inferior surface of the bladder which is not covered by peritoneum is in proximityto the upper rectum and is separated from it by the rectovesical fascia which contains the seminalvesicles and vas deferens. The prostate lies just below the bladder and surrounds the proximal partof the urethra as it emerges from the urinary bladder.Figure 42. URINARY BLADDERUreterm_Yertex261