Wednesday, November 16, 2011
Body Systems: Digestive System: Peristalsis
Here's another hands-on model to help your students get a feel for peristalsis.
The esophagus is made from a leg from a pair of tights or pantyhose.*
Cut the toe off in order to create a tube.
Place the egg in one end of the tube. Hold the 'esophagus' vertically so students can see that the food will not just fall through the esophagus - it's going to need a little help..
They will quickly realize that the egg moves best when the tights/pantyhose above it are squeezed.
Of course, we usually consume more than one bolus of food, so you can provide your students with a whole basket of eggs they need to get through the digestive system. Create several set-ups and have teams of students race!
*Remember the plastic eggs that pantyhose used to come in, back in the day? Those were the eggs I saw used in this activity originally. I don't believe you can find those any more (at least without purging your grandmother's house), so I used a large-sized plastic Easter egg. It works well, though its smaller than the original prop, and as such, you might want to use a child-sized pair of tights to make your esophagus.