1. EQ: How does our body eliminate cellular wastes?
The Excretory System
EQ: How does our body eliminate cellular wastes?

2. Function of the Excretory System
Removes excess water (H2O), urea, carbon dioxide (CO2), salt, uric acid, and other wastes from our blood.

3. Structures of the Excretory System
Skin
Lungs
Liver
Urinary System
Think – Pair – Share: Can you guess how these structures are a part of the excretory system?

4. Skin
Wastes such as excess water, salt, urea and uric acid are removed from the body in sweat.

5. Lungs
The lungs is a part of what other system?
The respiratory system

6. Lungs
Excess carbon dioxide waste is removed from the body when we exhale.
CO2

7. Liver Liver The liver is a part of what other system?
The digestive system
Liver

8. The Liver and Waste Liver
The liver produces urea and uric acid as a by-product of the breakdown of proteins.
Urea and uric acid are sent to the kidneys to be processed.
Liver

9. The Kidneys
Kidneys –filter the blood to form urine, which is excess water, salt, urea and uric acid.
Every drop of blood in your body is filtered by your kidneys more than 300 times per day!

10. How the Kidneys Work 1—Arteries bring blood to the kidneys.
2—Blood vessels branch off to nephrons.
3—Nephrons filter urea.

11. Eliminating Waste
Ureters – tubes that take urine from the kidney to the urinary bladder.
Urinary Bladder – a sack that stores urine.
Urethra – small tube that leads urine out of the body.

13. Excretory/Urinary System Video