The urinary bladder is a hollow, muscular sac that temporarily stores urine before it is expelled from the body. It can hold approximately 600 mL of urine prior to micturition. The bladder is retroperitoneal and located behind the pubic symphysis in the pelvic floor.
In males, the bladder is situated in front of the rectum, while in females, it is positioned anterior to the vagina and uterus. The bladder floor contains an inverted triangular area called the trigone, defined by the two ureteric orifices and the internal urethral orifice, which leads to the urethra.
The bladder wall consists of three histological layers: the mucosa, muscularis, and adventitia.
The urinary bladder is a hollow, muscular sac that temporarily stores about 600 mL of urine before micturition.
It is retroperitoneally situated on the pelvic floor behind the pubic symphysis. In males, it is positioned directly in front of the rectum, but in females, it is located in front of the vagina and below the uterus.
In the bladder floor, a small inverted triangular area called the trigone is formed by the two ureteric orifices and the internal urethral orifice, which opens into the urethra.
The bladder wall has three histological layers — the mucosa, muscularis, and adventitia.
The innermost mucosa consists of specialized folds of transitional epithelium called rugae. The mucosa permits the bladder to stretch as it fills with urine without leakage during storage.
The muscularis layer is made of a circular layer of smooth muscle fibers sandwiched between the inner and outer longitudinal layers. This forms the detrusor muscle, which regulates bladder volume.
The outermost adventitia is continuous with the ureters and is present on the posterior and inferior surfaces not covered by the peritoneum.
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