| A | B |
|---|
| excretion | the process by which wastes are removed from the body |
| urea | a chemical that comes from the breakdown of proteins and that is removed from the body by the kidneys |
| kidney | a major organ of the excretory system; eliminates urea, excess water, and other waste materials from the body |
| urine | a watery fluid produced by the kidneys that contains urea and other waste materials |
| ureters | a narrow tube that carries urine from one of the kidneys to the urinary bladder |
| urinary bladder | a sacklike muscular organ that stores urine until it is eliminated from the body |
| urethra | a small tube through which urine flows from the body |
| nephron | one of a million tiny, filtering structures found in the kidneys that removes wastes from blood and produces urine |
