1. What is Homeostasis?

2. Figure out what these pictures have in common and you’ll know a little more about HOMEOSTASIS?

3. What do they have in common?
All trying to BALANCE

4. Homeostasis- state of balance
Another word we can use is…
Equilibrium- a stable,
balanced, or unchanging
system

5. The human body wants to stay balanced.
When the internal and external environments are constantly changing, our bodies will:
- Shiver - Throw Up
- Sweat - Run Fever

6. Cells maintain homeostasis by:
Diffusion- The movement of molecules from an area of high concentration to an area of low concentration
High Low

7. Notice that the black dye is very dark until it is dropped into the water.
The high concentration of color moves to the lower concentration, no mixing needed!

8. More examples of diffusion
Water soaking into the soil after the rain
Perfume flowing through a room
Nutrients moving from your blood into your body cells

9. A type of diffusion that cells use is:
Osmosis- The movement of water in/out of another membrane.

10. Elodea cells before and after soaking in salt water
Elodea cells in normal pond water
Notice the empty space between the cell wall and the green chloroplasts!

11. Wouldn’t it be nice if we could really learn this way?