Bladder:A holloworganin较低的abdomenthat stores尿液．The kidneys filter waste from thebloodand produce urine, which enters thebladderthrough twotubes, called ureters. Urine leaves the bladder through anothertube,urethra．In women, the urethra is a short tube that opens just in front of thevagina．In men, it is longer, passing through theprostate glandand then thepenis．Also known asurinarybladder andvesical．
