1. Excretory System
What Life Process Does the Excretory System Help to Accomplish?
What Organs Are Part of the Excretory System?

2. Excretory System Includes the kidney, ureters, bladder and urethra.
Also called the urinary system

3. Excretory System Main organ: Kidney
Function: You have two kidneys that filter wastes from the blood. The wastes include urea, excess water and salts.
The waste excreted is called urine.

4. Nephron
All diffusion takes place in the part of the kidney called the nephron.

5. Help for the Excretory System!
Your liver plays a part in excretion.

6. Liver
Cellular wastes containing nitrogen build up in our bodies as ammonia. Ammonia is very toxic!
Our liver converts the ammonia to urea which is carried in the blood plasma to the kidneys where it is filtered our and excreted.
What else do you know about the liver?

7. Help for the Excretory System!
The skin plays a part in excretion.

8. Skin
Your skin gets rid of excess water, salt and urea through your sweat glands.
The waste is called sweat.
Adults produce between 0.5 and 10 liters/day.
Sweating not only removes wastes it also helps to keep your body cool, around 37 degrees C.

9. Help for the Excretory System!
The lungs play a part in excretion.

10. The Lungs
The lungs filter the cellular waste carbon dioxide (CO2) from the blood stream.
The blood carries this cellular waste to the lungs. CO2 diffuses from a high concentration in the blood to a low concentration in the lungs.
It is then exhaled and released from the body.

11. Questions:
Where does the waste excreted by the excretory system come from?
Why isn’t feces included in our list of things excreted from the body?

12. Malfunctions/Diseases
Kidney Stones
Kidney Failure
Urinary Tract Infections