Kidney Kidney The kidneys are two bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. 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. The nephron is the structural and functional unit of the kidney. Each adult kidney contains around 1 million nephrons. The nephron utilizes four processes to alter the blood plasma which flows to it: filtration, reabsorption, secretion, and excretion. The
Bladder pipe word which in medieval Latin was frequently used also for the bagpipe. In the earliest illustrated forms of bladder pipe, such as the well-known example of the 13th century reproduced by Martin Gerbert from a manuscript at Sankt Blasien Abbey in the Black Forest, the bladder is unusually large, and the chanter (or melody pipe) has, instead of a bell, the carved head of an animal. At first the chanter was a straight conical tube terminating in a bell, as in the bagpipe. The later instruments have a pipe of larger calibre more or less curved and bent back as