Thanks for continuing to check the HAPSblog! I am really excited about all the possibilities that are being uncovered through this blog and can’t wait to see where our conversations take us.
Last week at Chavez we wrapped up the nervous system and will begin the circulatory system next week. One things my students seemed to struggle with was conceptualizing the “action potential”. What great activities do you have to really cement the process/visualize an action potential? At my school, we do not have access to YouTube, so finding videos on the fly is not a possibility if I find my students are in need of another visual. Many of the videos I found at home on an action potential are not very engaging anyway… Do you know of any helpful simulations or visuals? How do you teach this topic in your classes? And, lastly, what depth of knowledge do you think is appropriate for a high schooler on this topic?
Action potentials are indeed challenging. Don’t have any magic fromula but do have a pet peeve. Many animations or illustrations show APs tavelling down a neuron as a flash of light. I realize that it is challenging to picture the process of ions rapidly moving across the membrane however by showing APs as light moving down the membrane I feel introduces a misconception that is difficult to erase. I would almost prefer a cloudy, blurry area on the membrane that when zoomed in on revealed in slow motion the sequence of Na ions followed by K ions moving .
I usually set up a row of standing dominoes. This demonsrtates that it doesn’t matter how hard you push the first domino, the AP goes at the same speed and with the same force.
I really like that idea! I’m now imagining a way to incorporate the dominoes onto a model neuron to actually show the AP travelling… I will have to play around with that idea. Either way, the dominoes would make a great visual. Thanks!
That’s a great point! I will definitely keep that in mind. It is so interesting to me how the seemingly smallest details can cause profound misconceptions later on. Thank you for your input!
If your class is big enough, doing a “stadium wave” where students stand up and raise their hands above their heads then quickly sit back down can work. Has lots of similarities to an action potential in which each student is an approximation of a small segment of the axon:
1) Excited only by the excitement of the neighbor
2) Jump up to mimic charge going positive
3) Usually come back to the chair lower than where they started
4) Quickly return to resting state as if nothing ever happened.
If you imagine that the next classroom is a another axon, you can imagine the space between the classrooms as a synapse and you can pick one or two students to be the neurotransmitters to run the signal of excitement over to the next room.
Not perfect, but better than a flash of light…
I use this in my classroom and I believe it helps. It takes very little time but I am a big fan of Kinesthetic learning. Another simple example for ATP. Have 4 students stand. Two students bond by linking arms. Third student is the loose phosphate. Fourth student is energy from electron transport chain. Now the energy pushes the loose phosphate into place. Oxidative Phosphorylation has taken place.
I’ve used the concept of Kerplunk, or Don’t Break the Ice, because it illustrates how you can have graded potentials (or electrical activity in general) at a receptor site that does no t cause an AP, but when enough straws have been removed/blocks knocked out, any further cause the game to be over.