The Excretory System Purpose: To remove waste products from the body Excess water -- Urea Salts -- Digested food Carbon dioxide -- Old RBCs Extra amino acids -- Poisons

Organs of the Excretory System Lungs – remove carbon dioxide (CO2). Capillaries release CO2 into the alveoli. The CO2 is then exhaled. Liver – removes used amino acids. Filters out old RBCs and poisons Produces urea (which is later removed by the kidney)

More Organs Kidney – Helps remove urea salts water digested food molecules from the bloodstream. Wastes mixed together and are known as urine

Urine Urine leave the kidney through the ureter It is stored in the urinary bladder When bladder is full, the urine is expelled through the urethra