Lesson 8

Lesson Objectives...

• Engage in an argument from evidence supported by scientific reasoning for how a healthy digestive system rearranges matter through chemical reactions and absorbs food, and how and why M’Kenna’s digestive system is functioning differently. 

• Analyze and interpret data to identify the relationship that taller villi (structure) have more cells that work together to impact the rate of absorption (function) of food molecules into the bloodstream.

Resources for Lesson 8...

Examining the Small Intestine

Use the images to take a closer look at the small intestine.  Record your observations in the Notice / Wonder Charts in your science notebook.

Examining the Lining of the Small Intestine

Use the images to take a closer look at the zoom in to get a look at the cellular makeup of the lining of the small intestine.  Record your observations in the Notice / Wonder Charts in your science notebook.

Simulation to Examine the Function of the Villi

Use the simulation to examine the function of the villi.  Change different variables to examine the effects on the absorption of food particles into the blood.

Instructions for the simulation set-up:

1. Use your Chrome browser to go to this website: https://openscied.org/villi-absorption/
2. Adjust the “end-simulation-at” slider to be any value above 12, and keep it at that value for all simulation runs.
3. Adjust the “initial-#-small-food-particles” slider to be any value above 100, and keep it at that value for all simulation runs. You can also adjust the “large particles” slider if you wish.
4. You can adjust the “villi-height” slider to be any of the values you want to test for villi heights.
5. Press the SETUP/RESET button to initialize the model.
6. Then press the GO/PAUSE button to run the model. 
7. When the model stops running, record the percentage of food particles absorbed into the blood in a data table you make below.
8. Repeat steps 5–7 if you want to do more than one trial for this villi height. When you are ready to test a new villi height, go back to step 4, make your changes, and repeat the remaining steps.

What we figured out this lesson...

• Body systems are organized by... Systems - Subsystems - Tissues - Cells

• M'Kenna's intestinal wall surface is flat and a healthy person's is folded back and forth (forming villi).

• Increased villi height results in more surface with as they flow through the small intestine; this results in a greater rate of absorption in a healthy small intestine that in M'Kenna'a.