Discuss the role of models in science. Continue the capsule journey as it travels through the intestine to find out how the body gets the nutrients it needs.
Complete Mini Activity: Coil a Rope as a model of the size of the small intestine.
Complete Mini Activity: Shake It Up as part of the discussion of emulsification.
Continue the discussion of digestive juices including the names, location, and actions.
Use the completion of Activity 4-1: A Journey through the Intestine (Peristalsis) to model and describe the movements of the small intestine.
Complete Mini Activity: What Passes across a Membrane?
Discuss the importance of a vast surface area of the small intestine for absorption as an introduction to Activity 4-2: A Journey through the Intestine (Villi).
Discuss diffusion and osmosis as they relate to digestion. Use Enrichment 4-1: Transport of Materials-Exploring Diffusion if time permits.
Continue the capsule journey through the digestive system observing the colon, the appendix, and the liver.
Complete Mini Activity: Drawing the Actions of the Digestive System.
Draw students' attention to the key ideas using means such as posters and overhead transparencies.
Select appropriate Enrichment Activities and Projects to complete if time permits.
Use the Apply Your Knowledge and Review Questions in reviewing the section.
Coil a Rope Students coil a 1′′ inch, 25-foot rope into the smallest space possible. They compare this coiling to the coiling of the intestines. They explain what features of the rope would enable them to fit it in a smaller space (i.e., flexibility-to produce the coils and folds).
Shake It Up Students put some oil and water in a jar with a tight-fitting lid and shake it. They watch the oil and water separate and then compare this action with what happens when they add some liquid soap (clear works best) to the jar and shake. The soap enables the water and oil to mix. Students then relate this mixing to the digestion of fat in the body.
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What are gallstones?
What Do You Think?
Now that you know how different kinds of foods are digested, think about what kinds of foods you digest first and what kinds you digest last. Why do you think you are not supposed to eat fatty foods before you exercise?