Urinary bladder collects in the bladder, fed from the two ureters that connect the bladder with the kidneys. Urine leaves the bladder via the urethra, a single muscular tube ending in an opening – the urinary meatus, where it exits the body. Anatomists divide the bladder into:. The apex (prev."vertex") is directed forward toward the upper part of the pubic symphysis, and from there the median umbilical ligament continues upward on the back of the anterior abdominal wall to the umbilicus. The peritoneum is carried by it from the apex on to the abdominal wall to form the middle umbilical fold. The
Urinary bladder that protects the cells beneath it from urine, the urothelium (a form of transitional epithelium), a basement membrane, and the lamina propria. The mucosal lining also offers a urothelial barrier against the passing of infections. The detrusor muscle is a layer of the urinary bladder wall made of smooth muscle fibers arranged in spiral, longitudinal, and circular bundles. Stretch receptors in the bladder signal the parasympathetic nervous system to stimulate the muscarinic receptors in the detrusor to contract the muscle when the bladder is extended. This encourages the bladder to expel urine through the urethra. The main receptor activated is