1. Excretion
Chapter 7

2. Excretion Excretion is the removal of wastes made in the body.
The three organs of excretion are the lungs, the kidneys and the skin.

3. Excretory Organs The lungs excrete Carbon dioxide and water vapour.
The skin excretes sweat (water and salts).
The kidneys excrete urine (urea water and salts). The kidneys regulate the amount of water in the body.

4. The Kidneys
Blood enters the kidneys in the renal artery and exits in the renal vein.
Urine passes from the kidneys, through the ureters, bladder and urethra to the outside.

6. Dialysis