The mesane, also known as the bladder, is a hollow organ in the human body that stores urine before it is excreted. It is located in the pelvis and is made of muscular tissue that allows it to expand and contract. The mesane plays a crucial role in the urinary system, which includes the kidneys, ureters, and urethra. When the mesane fills with urine, nerve signals inform the brain that it is time to urinate. The process of urination involves the relaxation of the sphincter muscles and the contraction of the mesane, allowing urine to flow out through the urethra. Proper function of the mesane is essential for maintaining fluid balance and overall health.