1.The Excretory System

2. Part of Homeostasis
Helps to maintain homeostasis
Removes metabolic wastes
If not removed, these wastes could be harmful
3. Different Waste Products
Your body produces many waste products
Some examples are salt, carbon, dioxide, urea
Urea: toxic compound produced when amino acids are used for energy
Wastes leave body through excretion
4. The Skin
The skin is an organ of excretion
The skin excretes water and urea in sweat
5. The Lung
The lungs are organs of excretion
They expel the waste product carbon dioxide.
6. The Liver
Converts amino acids into useful compounds
Nitrogen wastes are created in the process
The nitrogen becomes urea, which is expelled out of the body
7. The Kidneys
Remove waste products
Maintain blood pH
Regulate water content and volume of the blood
8. 9. Nephrons
Converts amino acids into useful compounds
Nitrogen wastes are created in the process
The nitrogen becomes urea, which is expelled out of the body
10. 11. Reabsorption
Some materials (water, amino acids, etc.) are reabsorbed into the blood
This primarily takes after filtration in Bowmans capsule in the loop of Henle
12. Secretion
Secretion is the process in which some molecules move from the blood to the filtrate
This takes place after filtration
Molecules secreted into the filtrate include hydrogen and other light compounds
13. Urine Formation
Urine: material that is not reabsorbed into the blood
Urine includes urea, salt, water,, and other substances.
Urine is located in the loop of Henle
Nephron Collecting Duct Ureter Urinary Bladder Urethra
14. Summary
15. Bibliography
Miller, Kenneth R., and Joseph S. Levine. "The Excretory System." Prentice Hall Biology. N.p.: Person Education, Inc., 2007. 985-989.


"Treatment Methods For Kidney Failure: Kidney Transplantation." National Kidney and Urologic Diseases Information Clearing House. 9 Jan. 2009 .
"Your Kidneys and How They Work." National Kidney and Urologic Diseases Information Clearinghouse. Aug. 2007. 11 Jan. 2009 .