Re: How do I make a model of the circulatory system?

Model of the Circulatory System (approximately grade 6 level)

To the best of my knowledge, there is no good way out there to model the circulatory system that won’t cost you lots of money. I would suggest however, resubmitting this question again if my answer does not help so that it might be assigned to someone else on the MadSci Network that might have an idea that I haven’t seen or thought about.

There are many fairly good and basic demonstrations on the web if you have that ability in the classroom, such as this explanation of the heart and circulation from the Mayo Clinic web site http://www.mayoclinic.com/health/circulatory-system/MM00636 . It’s a bit heart-centric in nature, but gets the job done in a clear way. Another simple thing to use to explain formation of vessels and how they branch etc is examining the leaf from a tree, such as a maple, or anything that has lots of “veins”.

Now, with that all said, there are some nice interactive classroom activities that can get the classroom going. They are largely variations on the same theme and get the class up and moving. You can add varying levels of complexity depending on what points you want to make and what you think the class can handle. A very good web-link that introduces the idea is http://www.brown.edu/Departments/Swearer_Center/Projects/PSO/Lessons/heart.htm .

Basically, having kids move from the heart to the lungs to the organs etc carrying oxygen or carbon dioxide either in the form of paper or balloons, could be red and blue to demonstrate oxygenation. Different organs could be placed around the classroom and students being blood cells could make there way from one to the next leaving oxygen, or removing waste, and carrying these things throughout the system. One could use classroom chairs or desks to vary the width of paths (vessels) as the kids go from one place to the next, this works especially well if perhaps they go off in groups of five or six and need to make there way around as a group, this is also a good way to look at blood clots and what their effects could be on blocking circulation. Another variation is the same sort of activity but strictly in the heart moving from chamber to chamber, to lungs and back, where one could even look at things such as if a valve were not working properly (maybe not opening quickly or creating some back-flow), then the groups of blood will start to bump into each other a bit (which kids find fun too). All of these can be done at various speeds to simulate increased heart rate.

One kit commercially available that looks to be fairly easy to make your own version runs as follows:
Picture a giant on the floor of a large (9 m x 9 m) area. In this activity, each group of students acts as volume of blood passing through the circulatory system of that giant.
As a group, students travel to all of the circulatory organs and systems. Along the way, they pick up or leave cards that correspond to local functions (like hormones, glucose, oxygen, cholesterol, etc).
Each time the pacemaker (teacher) directs the heart to contract, a new group of students enters the system, and the preceding groups move to the next stop on their "tour". http://www.sciencekit.com/category.asp_Q_c_E_762189

A more simple activity could be:
1. Show students a poster of the Circulatory System and tell them that we are going to turn the room into a circulatory system like the one in the poster
2. Ask for student volunteers to be the lungs, capillaries, left heart, and right heart. Instruct them where to stand and explain their jobs.
3. Tell the remaining students that they represent the blood in the circulatory system.
4. Have the students follow you through the classroom circulatory system, exchanging the red balloons for blue balloons and explain what is happening along the way.
5. Once everyone is back at the front of the room, have them follow you through again, but faster, and inform them that this represents a faster heartbeat.

The only physical model that I can think of would use tubing of different diameters that would fit together in lengths of decreasing and then increasing diameter, and a matching length of a single diameter and either with a water balloon or squeeze bottle or something similar, see which is easier to push water through or which you can push more water through in the same amount of time with the same pressure (or if you can think of a way to pull water through, perhaps if your school has a vacuum line in the lab that could pull water from a tub into a flask). This goes to demonstrate ideas such as heart strength, blood pressure, decreased blood flow due to vessels that have become smaller due to cholesterol/plaques, and so on.

I hope these examples were helpful and that you can use them with your kids.

Keith Anderson
Brigham & Women's Hospital, Boston, MA