The Urinary Organs

The urinary organs (Organa uropoiëtica) are the kidneys, ureters, bladder, and urethra. The kidneys are the glands which secrete the urine; they are red-brown in color, and are situated against the dorsal wall of the abdomen, being in most animals almost symmetrically placed on either side of the spine. The ureters are tubes which convey the urine to the bladder. The latter is an ovoid or pyriform sac, situated on the pelvic floor when empty or nearly so; it is a reservoir for the urine. The urine accumulates in the bladder until that organ is full, and is then expelled through the urethra.