1. Excretory System

2. The Excretory System
Function - Eliminates metabolic wastes from the body
The major wastes:
Carbon dioxide
Heat
Nitrogen
Salts

3. What are Metabolic Wastes?
Metabolism is the burning of nutrients for energy within the body.
Feces is mostly just leftover digested material. It never is burned for energy
Feces never truly is within the body
(remember the digestive tract is like a tube…)

4. What organs are involved?
Main Organs
Kidneys
Ureters
Urinary Bladder
Urethra
Accessory Organs
Lungs
Liver
Skin
These organs all have one thing in common: they eliminate wastes from the body.

5. Liver ~Accessory Organ~
Functions:
Produces urea (compacted nitrogen produced in the breakdown of protein)
Regulates sugar in blood
Breaks down old red blood cells and poisons and sends them to the kidneys for disposal

6. The Kidneys Main organ of the excretory system – filters blood
Located on either side of your backbone, slightly above your belly button in your lower back
Wastes Eliminated
Water
Salts
Nitrogen

7. Blood Filtration & Urine Production
Urea travels from liver to kidney in blood
As blood enters the kidney, it is forced through capillaries filtering out urea, excess water, and salts as they pass through millions of filtering tubes called nephrons.
Wastes that remain in the nephrons are considered urine.

8. Leaving the Kidney
Filtered blood leaves the kidneys and returns to the heart for circulation
The nephrons move urine to tubes known as ureters that extend to the bladder.
The more water your body eliminates, the clearer your urine

9. Urinary Bladder
Muscular, stretchy organ that stores urine for disposal
Holds roughly one pint, or 470mL, of urine for disposal
Voluntary or involuntary from this point forward?
Voluntary – You control when the urine leaves your bladder through the tube known as the urethra.

10. Lungs ~Accessory Organ~
Wastes Eliminated
Carbon Dioxide
Water
Heat
What system transports these wastes to the lungs?
Circulatory System

11. Skin ~Accessory Organ~
Wastes Excreted
Urea
Salts
Water
Heat
Heat is lost in two ways:
Capillaries shifted closer to the skin
Sweating

12. How do the excretory system and the digestive system work together?

13. If you said……..
. These organs in both systems all work together to convert food from its raw form into nutrients the body can use, while processing and disposing of the remaining waste materials….you are CORRECT!