Excretory System

What is the function of the excretory system?

1. Removes wastes from the body2. Cleans the blood3. Produces urine4. Involves the kidney and bladder

Processing Piece• Draw a picture to show that blood:

1) Absorbs nutrients in the villi in the small intestines2) Releases nutrients into cells and takes away the cell’s

wastes in capillaries3) Gets rid of wastes in the kidneys

What does the kidney do? • The kidney cleans the blood by filtering out

waste products, like uric acid.• The kidney turns the waste products into

urine, which goes to the bladder.

What does the bladder do?• Stores urine until it leaves the body.

What are the ureters and the urethra?

• Ureters are tubes that carry urine from the kidneys to the bladder.

• The urethra is the tube that carries urine to the outside of your body.

Processing Piece

• Draw a picture to illustrate how the kidneys, ureters, kidneys and urethra are connected.

How does your body control the amount of sodium (salt) in the blood?

• Kidneys control how much sodium goes into the urine.

• If there is too much sodium in the blood, more sodium will go into the urine.

Processing Piece:Review:• In the capillaries of normal cells and tissues:

o _____________________ goes out of the blood ando _____________________ goes into the blood

• In the alveoli of the lungs: o ____ goes into the blood and ____ goes out of the blood

• In the villi of the small intestines:o ______________ goes into the blood

• In the kidneys:o _______________ goes out of the blood

Exit Ticket

1. What is the function of the excretory system?2. What do the kidneys do?3. How does the excretory system help you

maintain homeostasis?