Hi guys! In case you were not aware, February is National Heart Month! Yes, it is that time of year where we bring awareness to heart disease and ways to prevent it. I hope you are all managing your risk factors and keeping yourself healthy no matter what month it might be. Here are some risk factors for heart disease:
1. Being overweight
2. High blood pressure
3. High cholesterol
4. Having diabetes
5. A sedentary lifestyle
6. A family history of heart disease
It is also good to have an annual physical with your doctor where these risk factors and more are assessed. As for myself, I need to work on including more aerobic type exercise in my daily routine. Working full-time and with kids, daily life can get hectic fast, making it difficult to squeeze in a workout. The good thing about heart disease, is that in most cases, it is preventable. It just takes knowing the risk factors, and taking the right steps to lower them. This is very important for us to know and to share with our students as well, especially as biology and health teachers.
Not only is February National Heart Month, but it is also time for all the yummy heart chocolates and pretty flowers to fill up the store aisles as St. Valentine’s Day is right in the middle of it all (It is also Black History Month!). That's a lot of good stuff to remember and to celebrate! So, with all this heart stuff going on, I think February is a great time to introduce the circulatory system lessons, if you can ever plan it that way in your classes.
Learning about the circulatory system can be confusing for some students, as there are many new terms being thrown their way and they must understand which parts of circulatory system are shown as blue and which ones are shown as red in heart diagrams and the why behind all of this. For the teacher, it’s a piece of cake because we teach it over and over every year, but sometimes we forget that it can be difficult for students to understand. This is why I like to think of different ways for them to “get it” .
Sure, you can show them a presentation slide show on this or explain the topic to them, this helps, but for many students they will also need hands-on-instruction. Kinesthetic learners learn best by doing, seeing, and touching things, rather than simply looking at notes.
This is why I love introducing clay into science lessons for students, because no matter the age, most students enjoy working with it, and so do most adults. It is kind of therapeutic to touch it and mold it into shapes, and it's is also a UNIQUE and ENGAGING way for students to learn the differences between veins, arteries, and capillaries. This is a lesson that I came up with using soft air dry modeling clay and a straw; where students will make clay blood vessels and a heart model.
Materials You Will Need:
-Red modeling clay (to represent the arteries, pulmonary veins, and left side of the heart)
-Blue modeling clay (to represent the veins, pulmonary artery, and right side of the heart)
-Purple modeling clay (to represent the capillaries)
-Yellow modeling clay (to represent plaque buildup inside artery walls)
-White modeling clay (to represent valves and the septum)
-Plastic straws, two straws for each student (to represent arteries and veins).*If you do not have enough clay, you can cut the straws in half. By cutting them, students would make shorter blood vessel models, in case you wanted to save on clay (like if you have large classes and not so much clay).
-Coffee stirrers (one per student, to represent capillaries)
*I have a Clay Blood Vessels and Heart Student Worksheet (3 pages) in my TPT store that I made to go with this lesson activity. It includes instructions on how to build a heart model too, and comes with a scoring rubric as well. As for the clay, you can purchase clay online or at any craft store. The one I like to use is the super light Sago Brothers air-drying modeling clay, It is easy to shape and won't take long to dry and it also comes in a big bag, so it goes a long way. But of course, there are a lot of good soft, air drying clays out there that you could use that work just as well. Just be sure to try it out first before using it for your classes.
*And as always, see too if parents can donate clay to your classes or go to DonorsChoose for help getting the clay for this lesson. This will save you money!
How to create a blood vessel clay model:
When you are ready to begin, take one of your straws and place red clay around it. Roll it and smooth it out with your hands until you get the desired thickness you want. This will represent an artery. See the picture below. Make a thick layer on it to represent the walls of arteries being thick-walled.
Roll it on a smooth surface, making sure to keep it a thick layer. You may need to keep adding clay as you smooth it out by rolling it. Insert a pencil inside each side of the straw as you work the wall to your desired look. This will prevent clay from entering the blood vessel model while you are smoothing out the wall, and will keep it hollow inside. When you are through with the shaping and molding of the blood vessel wall, then you may remove the pencils from each end of the straw. Students should be able to look through the straw after they are done and see a clear view of the other side (no clay inside) to represent a healthy blood vessel.
*You can even have students make a diseased artery model, representing atherosclerosis, using yellow clay as the cholesterol build up in the artery walls. See the picture below. Then students can place this model next to the healthy artery model and compare. One they can look through and see the other side of the room (healthy), the other they will not be able to, or not as well (diseased). Let them know that the diseased artery is likely to contribute to a heart attack or stroke if left untreated. In my cardiovascular disease presentation, it goes over the risk factors for heart disease.
Diseased Artery
Healthy Artery
*Now you will do the same thing for the vein, but using the blue clay instead of the red, and you will make the walls thinner than the artery model. For this one you will need to work in valves (white in picture) at two the opening of the straws. It will be a bit tricky to get the valves in, but with a little patience and a few trial and errors, it should come together okay. See the vein model picture below and the vein and artery side by side picture. Notice, the artery model's wall is a little thicker than the vein model's wall.
Finally the capillary, for this model, students will use the coffee stirrer sip straw-the thinnest of the straws to represent a capillary. Remind students that in the body these are tiny, microscopic vessels, they are so narrow that red blood cells travel through them single file! For these models, we just want them to be able to show that the capillary is the thinnest of the other two, as we can't make them microscopic :). The point is for students to know they are then thinnest of all the vessel types, so as long as they can show this in their model comparison, it is all good. Once these models dry, they are easy to handle and can be displayed on their desk at home.
A Cool Extension:
You can also have your students make a model of the capillaries with them connected to the arterioles, venules, veins, and arteries. They can make these on a small-sized poster board with their names on it. For this model, unlike the individual capillary model shown above, students will NOT use coffee stirrer sip straws to make the capillaries. This way they will be able to shape and bend them in their model. They will just make thin strips of clay to form the capillary network and connect this to the individual artery and vein blood vessels that they made first in this lesson. Students can make the capillaries purple and then it connect them to venules and veins and arterioles and arteries (as in the picture below).
Or if you prefer, you can have them use red and blue clay for the capillaries, instead of purple. The red in the model represents oxygen-rich blood going from the arteries to arterioles (smaller arteries) then leading to capillaries where oxygen diffuses from the capillary to go to cells, and carbon dioxide is picked up. This is why the other side of the capillary net is blue, it is deoxygenated and leads to venules (smaller veins) and then moves to veins to return to the right atrium. Once back to the heart, blood is pumped back to the lungs to get rid of the carbon dioxide and pick up more oxygen.
If they choose to represent the capillaries with red and blue clay, then their model would something look like the one below. When they are finished, you can even have them write on an index card a brief explanation of their model and toothpicks with labels to identify the different blood vessels in their model.
Okay, one last clay model suggestion! If you'd like your students to make a model of the human heart too, they can create a heart model using a heart template that they will place the clay over. My clay blood vessel model worksheet includes a template in it, along with instructions on what to include in their clay heart model in case you wanted to check it out.
Like I said, February is the perfect time for including circulatory system lessons, but whatever lesson you choose to teach in February, just be sure to take the time out to remind students the importance of keeping up with their heart health. After all, they only have one heart.:)
Extra Heart Fun in Your Class
Your students will enjoy playing a round or two of bingo, too, while studying the heart unit. I have a Cardiovascular System Thinking Bingo in my store that is educational and fun, and can make for a great in class review.