urinary bladder

Definition : The urinary bladder is a hollow muscular organ in people and animals that collects and stores urine from the kidneys before disposal by urination. Adj. vesical

In the human, the bladder is a hollow muscular, and distensible (or elastic) organ, that sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra. The typical human bladder will hold between 300 and 500 mL (10.14 and 16.91 fl oz) before the urge to empty occurs, but can hold considerably more.

The outside of the bladder is protected by a serous membrane. The bladder wall itself is smooth muscle. The inner side of the bladder is lined with a mucosal membrane consisting of a surface glycocalyx that protects the cells beneath it from urine, the urothelium (a form of transitional epithelium), a basement membrane, and the lamina propria.