As we have moved on to the respiratory system, I really felt strongly about building some kind of simple, hands-on model that the students could use to visualize respiration. To build our models, we used empty water bottles, balloons, straws, and clay (with a limited budget and no lab space, activities like this are wonderful!) The students really enjoyed it and were quite proud of their models.
The process of then writing an explanation to go along with the model definitely helped to solidify the main, general points of respiration and the changes that occur within the body. I was very impressed with some of my students’ insight and detailed explanations! For being such a simple model and activity, I think it was a very successful and helpful visual tool. I know there is always room for improvement, and would love your feedback about this model. Do you see anything that could potentially be misleading or inaccurate?
Also, in our discussions of how and why breathing occurs, some of my students really struggled with the idea of air pressure (atmospheric pressure and air pressure in the thoracic cavity). What is the most straight-forward/simple explanation you can think of to describe this process? When I stepped back to think about it, there really is a lot of foundational knowledge required to understand “air pressure” and without first having a refresher over chemistry and physics (atoms, particles, vacuums and the space between particles, pressure, etc), I had a hard time coming up with a simple, yet accurate enough explanation.
I really like your models!
I explain inhalation using the analogy of a syringe – when you pull the plunger/diaphragm back, the volume inside is larger but the amount of air inside has not increased. So whatever med you have the needle in moves up into the barrel of the syringe. Students find it easier to visualize this when they think of a fluid moving up into the syringe, and then they can relate that image to air moving in.
One year I did the lung model and then had the students give their models different disorders of inhalation — wounds in the chest wall or in the lung — and see how inhalation was affected.