1. EXCRETIONAND EXCRETORY PRODUCTS Created By: Reynaldo Thomas

2. What is excretion?  The elimination of metabolic waste products  Faces include excretory products, because they include metabolic wastes ( bile and mucus).  Excretions are toxic and must be removed, because high concentrations can damage the body tissues.

3. Importance of excretion  It helps in the maintenance of salt balance in the blood.  Helps in the removal of metabolic waste that may be poisonous to the organism.

4. Removal of unwanted Substances Carbon dioxide Removed during exhalation In gaseous exchange, carbon dioxide diffuses from capillaries into the alveoli of lungs. The carbon dioxide rich air then expelled into the atmosphere.

5. Water In excess water can be very harmful to the organism. (put strain on heart) A small amount is removed from the body during exhalation as water vapour. As we sweat we lose water. Urine contains a large amount of water and is expelled during urination.

6. Salts and ions Released from body during sweating and urination. Nitrogenous wastes Released during urination via kidneys A small amount is released in our sweat.