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 only distinction being the form and size of the air-chamber, either the bladder or the wind-cap, in which the reed was set in vibration. The player blows air into the bladder through the insufflation tube, or through the raised, slit-shaped opening of the wind cap, placed against the player's lips. This earlier Italian form of bladder pipe is found illustrated at the end of the 15th century in the Book of Hours, known as the "Sforza Book". An allusion to the bladder pipe occurs in an old English ballad: This excerpt suggests the early English bladder pipe retained a distinct