1. Excretory System
Key Point #1: There are three main organs in your excretory system
Skin
Kidney
Bladder

2. Skin Sweat is released out your sweat glands
Excretes extra water and salt in the form of perspiration (sweat)
Sweat is released out your sweat glands

3. Kidneys
They are located on either side of your spinal cord in your lower back.

4. Bladder
The bladder stores urine

5. The Excretory System
Key Point #2: The excretory system has four main functions
Get rid of excess water and salts in your body
Maintain the pH of blood [acid level]
Remove waste products from the blood
Control the amount of water in the blood

6. Where in the body does filtration actually occur?
Key Point #3: Blood is cleaned (filtered) in small units of the kidneys called nephrons.

7. Steps of blood filtration in the kidney
Blood filled with waste enters the kidney through the renal artery
The kidney removes urea, excess water, and other waste products from the blood
Urea= the major waste product in your blood
The clean, filtered blood leaves the kidney through the renal vein and returns to circulation

8. Where do all the wastes go?
Key Point #4: The waste products taken from the blood travel from the kidney to the urinary bladder through a tube called the ureter

9. These wastes are then stored in the bladder as urine
Eventually the wastes exit your body through the urethra

10. Summary Renal arteryKidneynephron Ureterbladderurethra
Blood must be cleaned (filtered)
Wastes in the blood follow this path
Renal arteryKidneynephron Ureterbladderurethra

11. Guided Practice
Which of the following best describes the word filtration?
Adding good things to your blood
Removing the bad things from your blood
Separating red and white blood cells
Cleaning urine before exiting your body

12. What are the 3 organs of the excretory system?

13. What is the tube called that takes urine from the bladder to outside the body?

14. Which of the following organs stores urine?
a)Urethra
b)Urerter
c) Bladder
d) Kidney

15. Which of the following organs actually filters your blood?

16. What are the small units in your kidney that filter blood?

17. What is “c” called? D A C B

18. Which structure brings blood into the kidney?

19. Which of the following is not a waste product produced by your body?
Oxygen
Urea
Carbon dioxide
Salt

20. The renal vein returns ___________ to the body while the ureters deliver _____________ to the bladder
urine; blood
Urine; urine
Blood; carbon dioxide
Blood; urine

21. Which of the following is in the correct order?
bladder, ureter, urethra, kidney
Renal vein, kidney, ureter, bladder, urethra
Renal artery, kidney ureter, bladder, urethra
Kidney, bladder, ureter, urethra