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
Pneumatic bladder Pneumatic bladder A pneumatic bladder is an inflatable (pneumatic) bag technology with many applications. Pneumatic bladders are used to seal drains and ducts to contain chemical spills or gases. Pneumatic bladders are often used for the containment of chemical spills, oil spills or fire water on water to prevent them from entering the environment, usually in the form of booms. The Reef Ball Foundation uses a pneumatic bladder technology to float an artificial coral reef ("reef ball") into location, then deflate the bladder to sink the reef to the bottom. Pneumatic bladders, known as dunnage bags, are used to stabilize