Wednesday, November 16, 2011

Body Systems: Digestive System: Peristalsis

Although gravity aids in the swallowing of food, it doesn't work alone.  Our body actively pushes each food bolus through the digestive system, a process called 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.

The food bolus is represented by a large plastic egg. 

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.. 

You can return the set-up to the table and have students determine the best way to move the food through the tube. 

They will quickly realize that the egg moves best when the tights/pantyhose above it are squeezed.

This is comparable to the muscles in the esophagus constricting and pushing the food throughout the digestive system.

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. 

5 comments:

  1. Superb blog.The human digestive system is constructed of hollow tube like organs. You may wonder to know that if you place digestive system parts one after the other, the formation will be 9 meter long!

    For more information related to this Please visit : digestive system and excretory system , medical animation and Focusappsstore.com

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  2. Thanks very much, we used your ideas in a digestive system project this week - here is my blog post with links to your site! great stuff! http://little-blossoms-childminding.blogspot.co.uk/2013/04/learning-about-digestive-system.html

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    Replies
    1. Thanks for the link! I really liked your experiment with acid secretions. I may have to play with that idea myself :)

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  3. My daughter has achalasia. She has zero peristalsis, so this made me laugh. It really is a great visual demonstration. It's just that gravity is ALL a person with achalasia has. I told my daughter she would need a really stretched out pair of panty hose.

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