Vocabulary/Definitions
Adrenal Gland: A gland that sits on top of each kidney and produces hormones.
Bladder: The sack in the lower abdomen that holds urine.
Bowman's Capsule: A small nodule of tissue consisting of an outer wall and a small bunch of
capillaries bunched together inside separated by a space; functions as a part of the filtering system,
allowing wastes to pass through the walls of the capillaries and into the proximal tubule; named for
William Bowman.
Collecting Duct: Tubes inside the kidneys that collect waste products from the rest of the filtering
system and move the wastes into the ureter.
Dialysis: The process of separating substances in solution by diffusion through semipermeable
membranes; hemodialysis refers specifically to purifying blood by dialysis.
Excretory System: The system made up of bladder, kidneys and connecting tubes that cleans the
blood and excretes waste from the body (also called the urinary system).
Glomerulus: Small bunches of blood vessels or capillaries inside each Bowman's capsule that act as
waste expulsion stations for salts, minerals and other waste products expelled from the blood stream.
Henle Loop: U-shaped loop in the proximal tubule that slows the passage of waste to allow reabsorption of water.
Nephron: The filtering unit inside the kidney used to filter impurities and waste from the blood.
Proximal Tubule: A tube connecting glomerulus to collecting ducts within the kidney.
Renal Artery: The main artery that brings blood into the kidney to be cleaned.
Renal Vein: The main vein that takes cleaned blood out of the kidney and back to the heart.
Ureters: Tubes connecting the bladder and the kidney.
Urethra: The exit tube from the bladder.
Urinary System: The system made up of bladder, kidneys and connecting tubes that cleans the blood
and excretes the waste from the body (also called the excretory system).
Urine: Liquid waste expelled from the body.