1. JH-KEADLE
The Excretory System

2. Excretory System
Facts!
As cells perform the chemical activities that keep you alive, waste products such as carbon dioxide and ammonia are formed.
To maintain homeostasis and keep you healthy, they must be removed.

3. Functions of Excretory System
Rids blood of wastes like urea, ammonia, and carbon dioxide.
Controls blood volume by removing extra water produced by cells.
Balances salts and water so cells can function properly.

4. Excretory System Organs kidneys ureters urinary bladder urethra lungs
skin
lungs
sweat glands

5. Organs of Excretion
There are other organs in our body that can excrete substances
lungs – carbon dioxide and water vapor are exhaled
skin – excess salt is released when you sweat.

6. Organs of the Excretory System
kidneys –filters blood and eliminates cellular waste. Returns salt, ions and glucose to the blood.

7. Organs of the Excretory System

8. Organs of the Excretory System
ureters – two narrow tubes that urine flows through to get to the bladder.

9. Organs of the Excretory System
urinary bladder – sac-like muscular organ that stores urine.

10. Organs of the Excretory System
urethra – tube that urine travels to leave the body.

11. The Filtering Process
Your cells have to maintain a certain level of water and salt to function properly.
nephrons – tiny structures
that filter blood in the
kidneys.
Vocabulary Word!

12. Filtering Out Waste
After entering the kidneys, blood flows through smaller and smaller arteries.
The blood eventually reaches a cluster of capillaries called nephrons.
In the nephron, urea, glucose, other chemicals, and some water move out of the blood and into the nephron.

13. Filtering Out Waste Blood cells and proteins stay in the capillaries.
Glucose, water, and small amounts of other substances are reabsorbed into the blood stream.
Urea and other wastes stay in the nephrons.

14. Filtering Out Waste The liquid left in the tube is urine.
The urine moves down the ureters and into the bladder.
When the bladder is full, you feel the urge to urinate.

16. Filtering Summary 1. both wastes and needed materials are
filtered out of the blood
2. the needed material is returned to the
blood
3. the waste is eliminated in the urine

17. Analyzing Urine Some medical problems can be found by testing urine
Glucose – diabetes
Protein – kidney failure
Drug residue – drug abuse

19. Body systems that work with the excretory system;
circulatory system to carry waste to the kidneys.
respiratory system to remove carbon dioxide.
integumentary system to remove salt.

20. Comparing Cells to Body
What cell organelle helps to break down waste?
lysosomes
What cell organelle packages waste?
golgi body