08/05/2025
In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organs[1] that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation.[2][3] They are located on the left and right in the retroperitoneal space, and in adult humans are about 12 centimetres (4+1⁄2 inches) in length.[4][5] They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder.