| A | B |
| excretory system | removes wastes with the aid of several systems |
| skin | removes excess salts by sweating |
| urinary system | rids blood of waste |
| kidney | bean-shaped organ that filters blood |
| nephron | filtering units in kidneys |
| ureters | tubes connecting kidney and bladder |
| bladder | elastic, muscular organ that holds urine |
| urethra | tube that carries urine from the bladder out of the body |
| urine | liquid waste of kidneys that contains excess salts and water |
| lungs | removes carbon dioxide from the body |