Circulation Excitation

During my first class the other morning we were learning about the Circulatory System. This followed our study on Blood. While the students had seemed indifferent about what blood is made of, they seem excited to learn about how the heart works and how blood gets moved around the body.

courtesy of Pixabay CC0 Public Domain

While the students asked many good questions, some of the questions had me shaking my head and trying hard not to laugh.

One student asked me if the blood vessels help hold our bodies together. He was looking at a drawing of the circulatory system in the text book and noticed how it looked like a net. I asked a few questions to determine how he’d come up with his question and was impressed with his thinking. He recalled from previous lesson on blood clotting how platelets underwent a chemical change to form fibrin and how the fibrin basically formed a net that captured other platelets and blood cells to form a clot to stem bleeding. He extrapolated from that knowledge the idea of the blood vessels acting as a net to hold the body together.

We decided after discussing his idea that it does seem as though the blood vessels could perform this function. However, I encouraged him to revisit his idea after we finished our study of the circulatory system.

Another student then asked, using an automobile metaphor, if our blood was more like motor oil than gasoline. He reasoned it was more like motor oil since it got pumped around our body like oil gets pumped around an engine over and over again where gas gets burned up and is gone. I’m still thinking about that one.

One of the best comments came from a young lady while we were discussing what happens to blood when it flows from the heart through the lungs and back. She likened the blood flowing to the heart as a car full of old fast food bags going to a drive up. The car stops at the trash receptacle to dump out the old used up paper bags and wrappers – the carbon dioxide - before pulling up to the drive up window to replenish with fresh food - oxygen.

It is classes like this, when the students start making their own connections and show a real understanding of the topic, that rekindle my excitement about teaching and, for a short time, I’m don’t feel quite so exhausted by my efforts to educate these kids.

As always, I remain,

The Exhausted Educator