Urinary bladder Urinary bladder The urinary bladder is a hollow muscular organ in humans and some other animals that collects and stores urine from the kidneys before disposal by urination. 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 (10.14 and ) before the urge to empty occurs, but can hold considerably more. In humans, the bladder is a hollow muscular organ situated at the base of the pelvis. Urine
Urinary bladder lateral ligaments of the bladder into the internal iliac veins. The lymph drained from the bladder begins in a series of networks throughout the mucosal, muscular and serosal layers. These then form three sets of vessels: one set near the trigone draining the bottom of the bladder; one set draining the top of the bladder; and another set draining the outer undersurface of the bladder. The majority of these vessels drain into the external iliac lymph nodes. The bladder receives motor innervation from both sympathetic fibers, most of which arise from the superior and inferior hypogastric plexuses and nerves, and