1. The Excretory System

2. The daily activities of cells involve many chemical reactions as they use energy from food. Waste products are formed as a result of these activities and they pass out of cells and into the blood. In order to maintain a balance in the body, the blood must be cleaned of these wastes. This process is called excretion.

3. The Kidneys
There are several organs in the body that get rid of wastes. (They are also parts of other systems.) The kidneys are the organ that are responsible for cleaning the blood.

4. Your kidneys are 2 bean shaped organs about the size of your fist
Your kidneys are 2 bean shaped organs about the size of your fist. They are located in the back just above the ribcage.

5. The kidneys contain about a million small structures called nephrons that filter the blood. They remove waste products and extra water which becomes urine.The urine flows through tubes called ureters to the bladder to be stored until you go to the bathroom.
Did you know that your kidneys filter about 2 gallons of blood in one hour?

6. Other Excretory Organs
Your large intestine is an excretory organ that gets rid of solid waste. What other system is the large intestine a part of?
Your lungs are another excretory organ. What waste do the lungs excrete? What other system are they a part of?
Your skin is an excretory organ. What waste do you think the skin excretes? What other system is the skin part of?

7. Some of the waste products your body gets rid of include:
Water
Carbon dioxide
Salt
Nitrogen
Urea (chemical that comes from the breakdown of proteins; contains nitrogen)
Heat

8. Individual cells must also get rid of wastes
Individual cells must also get rid of wastes. The organelle in a cell that eliminate wastes is the lysosome. A cell’s vacuole stores waste until it can be eliminated.

9. Excretion is:
The wastes your body must get rid of include:
The organs that get rid of wastes are:
In a cell, the organelles that do the job of excretion are:
The excretory system in your body is like what service provided by the city?