Active Teaching of Action Potentials

Kids 3One of the most difficult concepts for my students to grasp during Project Lead the Way’s Human Body Systems course is the concept of an action potential.  Before learning about action potentials, we do some basics with neuron structure.  Students start by putting together a puzzle of a neuron and coloring it.  I then take the 3 best colored/labeled neurons and we hang them on the wall, connecting them to represent a sensory neuron, interneuron and motor neuron.

Giant Neurons

Students work in teams to make labeled 3-D models of a motor neuron and they research what the parts of a neuron do.

Neuron Poster

Once students have grasped the basics of neuron structure, they do some research to learn about action potentials.  My favorite site to use is the Harvard Action Potentials Animation.  Students should go through it slowly several times, taking careful notes.  Below are my sample notes from my own interactive notebook.  Students can make the 3 flap shutterfold by folding a piece of paper in half and cutting 3 flaps.  I show students how to do that step.  I allow students to CHECK their notes off mine, but they cannot view my Notes Journal until they complete their own notes.

I give each student a copy of the action potential summary table to fill out as well.  I find that the table really helps them to process all of the information.

Action Potential Table

After laying the ground work, I want to give kids a kinesthetic experience with all that they’ve learned.  I tried a couple activities from other people and ultimately synthesized them into my own.  The one that I drew the most inspiration from was Pom Pom Potentials and it’s a great alternative to the one I came up with (and simpler to set up).  For my activity, I wanted to physically add in the channels and pumps, so I took it a bit further. Below are my students completing this activity.


To do my activity you need the following materials:

  • 6-8 pool noodles (for 24-32 students respectively)
  • 6-8 orange Solo cups (substitute any color)
  • 6-8 green Solo cups (substitute any color)
  • 6-8 paper plates
  • A hot glue gun
  • A box cutter
  • A Sharpie
  • Duct tape
  • 450 wooden blocks separated into a pile of 150 and a pile of 300
  • Orange and Green spray paints (substitute any color, but make sure they match cups)

Here’s how to set it up.

  1. Use duct tape to show which is the “inside” and which is the “outside” of the membrane (pool noodles).Noodles 2
  2. Use the box cutter to cut an opening in the bottom of every cup.  Make sure the opening is large enough to let your blocks pass through.  You may want to leave the flap of plastic there so you can represent the channel opening and closing.
  3. Label all of your orange cups Na and glue them to the pool noodle with the arrow showing the the sodium ions will pass from the INSIDE to the OUTSIDE of the membrane. Glue one to each pool noodle.Noodles 4
  4. Label all of your green cups K and glue them to the pool noodle with the arrow showing the the potassium ions will pass from the OUTSIDE to the INSIDE of the membrane.  Glue one to each pool noodle.
  5. Label each of your paper plates to show that 3 Na ions will pass to the OUTSIDE and 2 K ions will pass to the INSIDE.  Glue one to each pool noodle.Noodles 3
  6. Spray paint 300 of your blocks orange to represent the sodium ions and 150 green to represent the potassium ions (if using a different color, make sure they match the cups).
  7. Lay out all of your pool noodles on the floor as shown below.  The insides of the “membrane” should face each other.  Put the sodium ions on the outside, spread evenly and the potassium ions on the inside, spread evenly.  This represents the neuron at resting potential.  Interactive Set up
  8. Consider putting some “DNA” on the inside to help explain why the inside has a negative charge.  In the pictures of my students, you’ll see 2 students standing inside the membrane holding boxes of DNA models for this purpose.Kids 1
  9. Randomly assign 1/4 of the students to be potassium channels and have each claim a green cup and sit on the INSIDE of the membrane at their green cup.
  10. Randomly assign 1/4 of the students to be sodium channels and have each claim an orange cup and sit on the OUTSIDE of the membrane at their orange cup.
  11. Put the remaining half of your students in teams of 2.  Each team will run a sodium potassium pump together.  Have one student sit on each side of the pump.  Give these students a small bag of candies (I gave them chocolate chips).Kids 3
  12. Instruct the sodium potassium pump students that they MUST work together with their teammate.  Every time there are 3 sodium ions inside and 2 outside, they need to lay them on the plate, push them to the other side of the membrane and eat a chocolate chip to represent ATP.  They do this EVERY CHANCE THEY CAN.
  13. Have the students determine which end of this axon should be the dendrite end and then stand at that end.  Instruct the sodium channel students NEAREST TO YOU to open the channels and start pushing sodium ions through (only the 2 students closest to you should do this).  Interactive Action Potential BeginsStudents should count out loud as they push them through.  When students reach 15, that’s the “thresh-hold” and should trigger the potassium channels next to them to open.  Have those students start passing potassium ions out of the membrane.  Remind the Na/K pump students to operate the pump ANY TIME THEY CAN.  The picture above shows how the ion concentration will change as the action potential starts.
  14. As the potassium channels nearest you finish passing 15 potassium ions through, move down the axon to show the action potential moving.
  15. Have students switch roles and run the simulation again.

I found that while this activity helped them much better understand the channels and pump and how they work, they still struggled to connect all this to polarization and depolarization.  In the future I’ll have us draw the graph of an action potential on our lab tables in chalk markers as we do each step and label the parts of the graph based on what happened.

Action Potential Notes 2

I’d love to hear from you.  How do YOU teach action potentials?  What works for your kids?  If you try this activity, please let me know if it worked for you.  And if you have questions, please post them.


Become a Twitter Teacher

Never used Twitter or tried it and couldn’t quite figure it out?  I started on Twitter just a couple years ago and have found it to be an incredible tool to use to grow as a teacher and to use with my students.  In this blog post, I’ll help you get started on using Twitter.  You’ll learn how to:

  1. Create a Professional Twitter Account
  2. Follow the Right People
  3. Use Your Account

1. How to Create a Professional Twitter Account

For your account to be professional, it’s important that you use your real name and pick a handle (username) that relates to what you do.  Your username can certainly be your name (i.e. @HeidiHisrich), or you can go with something tied to your interests (my username is @2thedorkside).  Your actual name will show up along with your username, so it’s not critical that your username be your actual name, though many would consider that to be simplest and most professional.  Follow the steps shown in the slideshow below to set up your account.

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2. How to Follow the Right People

Who you follow determines what you see in your news feed, who you can message, and helps show your interests.  It also often determines who follows you back and who you interact with on Twitter, allowing you to customize your experience.  Some people use Twitter for personal reasons and solely as a social tool, but I use it only professionally, to build a professional network, learn from people with similar interests, and grow in my content area, so following the tips below will allow you to do the same.

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3. How to Use Your Account

To be a Twitter user, you have to Tweet.  Follow the steps below to compose tweets, favorite them, reply to them, and retweet.  Also learn how to check your feed and respond.

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4. What’s Next

Congrats! You’ve set up your account. Questions? Tweet at me! Mention @2thedorkside. Alternately you can comment below.

This blog post will help you get started on Twitter, but there’s SO much more you can do than what you see here. Stay tuned for upcoming posts to learn how to do the following:

  • Participate in chats linked to your interests
  • Help students create accounts
  • Get students started with their accounts via a Twitter Scavenger Hunt
  • Use Twitter and TweetDeck as a way to have students engage one another during lessons
  • Use Twitter as an assessment tool

To make sure that you get a notification about the next blog post, subscribe to this blog or to the Mailing List on the BiomedHeads website.



Raising Money by Selling Science!

It turns out Richmond kiddos can’t get enough of SCIENCE!  And who is helping kids develop a passion and understanding for science?  RHS HOSA students are!

valentines 2
Students get liquid nitrogen dribbled on their hands during Science and Romance (photo credit Pal-Item)

Our HOSA Future Health Professionals chapter formed during the 2013-2014 school year and many of our participants expressed the need for financial assistance so we immediately started brainstorming fundraising.  Over the past 3 years, we’ve tried many different fundraising techniques, but have discovered that the absolute best way for our team to raise money is to play to our strengths and sell science.

Our top 3 fundraising efforts have been:

  • Science and Romance: Valentine’s Day Baby-Sitting with a Twist
  • Science Saturdays
  • Camp Biomed

Science and Romance

The very first fundraiser we planned was called Science and Romance: Valentine’s Day Baby-Sitting with a Twist.  The idea was simple–parents get romance while kids get science.  We held the event at our high school and used 4 different classrooms, our conference room, the nursery and the cafeteria.  We scheduled the event to run from 5-9 pm and asked parents to feed kids beforehand or pack a sack dinner, though we did provide snacks.  Parents that registered kids in advance got a bargain rate of just $10/kid and those that came the night of paid $20/kid.

The event was a huge success, with ~100 kids attending and $1,000 raised (we spend around $200, but that money was covered by sponsorship donations).  As it was our very first experience, we made many mistakes that we learned from and have avoided since.  Here’s the short list:

  • We didn’t assign particular kids to particular chaperones (we had walkie talkies to coordinate, but it was sort of a zoo!)
  • We planned the thing for four hours (Need I say more?!  Four hours is an insanely long time to watch 100 kids!)
  • We accepted kids of all ages (people dropped off infants and we had a nursery… never again)
  • We required pre-payment (getting payment to me before the event was a huge pain)

We thought we had planned more than enough activities, but found that kids flew through them, leaving us at sort of a loss.  RHS HOSA kids had to improvise with games and some YouTube videos to help make it through the night.  Here’s a list of some of the science that we did:

Every fundraiser gives us an opportunity to learn and for future events we made the following changes:

  • Assign every kid to a certain chaperone and match kids to chaperones via color-coded nametags or wrist bands (link is to the style we use)
  • We limit our events to 2-3 hours
  • We accept only children that are potty trained
  • We ask people to pre-register online (using a Google Form), but we take payment at the door

This year for Science and Romance we actually coordinated with our local science museum, holding the event there and partnering my HOSA students with their museum students for a great collaboration!

Science Saturdays

Science and Romance was such a hit that we knew we needed to follow it up with some more science opportunities for young kids.  We got the idea of Science Saturdays from South Dakota HOSA Advisor Barb Schmidt, who had gotten the idea from another colleague.  In Spring of 2014, we started offering Science Saturdays, using the following set-up:

  • Theme for every Saturday (Candy Science, It’s Electric and Egg-Citing Experiments were the first few topics)
  • 9-12 am time slot
  • Snack offered midway through
  • Rotation through 4-8 stations
  • A packet for recording information
  • Online registration beforehand and payment at the door
  • Fee of $15-20, with scholarships offered (was $15 for 2 hours, $20 for 3)

This year we once again ran Science Saturdays, but with the following changes:

  • Each ran 2 hours (9-11 am) and fee was $20 for the first child, $15 for the 2nd child and $10 for each additional child in the family (this is to account for supply expenses, which we expect to be higher)
  • No snack was offered (was a pain and expensive)
  • Cap of 28 students so we could all be in my lab
  • No packets (that felt like school and many aren’t old enough to read/write so instead each table will have a white board for predictions and the HOSA volunteers will jot them down for younger kids)
  • At least 2-3 Take Home Science activities each time and the option to buy extra “take home science” packages for $10 per pack (great gifts!)

This year’s Science Saturdays were themed and included Balloonapallooza, Rockin’ Rainbow Science and Bombdiggity Blast.

Each came with a Take Home Science Kit (came with admission, but extra kits were also available for purchase at a cost of $10 each).  For example, the Balloonapallooza Take Home kit included the items below (plus a few more goodies).

For more details about Science Saturdays, visit our website.  We also send an e-mail and attaches flier to the whole Richmond Community Schools list serve and our local college (Earlham).  And we keep a running mailing list using MailChimp.  Promotion is key!

Last year we earned an average of $400-$500 per Science Saturday.  And the testimonials from parents and kids let us know we are making an impact.

My 3 year old daughter had a great time and was so excited when she came home. She was able to demonstrate the experiments and explain how they worked. The teachers and students did an amazing job and I highly recommend anyone considering this event to sign up…it is well worth it. Thanks so much to everyone involved. We will definitely be attending any Science Saturdays offered in the future!  –Kelli Barnes

Camp Biomed

We also wanted to create an opportunity for older students to have fun doing science and promote our PLTW Biomedical Science Program.  So in June of 2014 we offered our first ever Camp Biomed.

We had a group of about 18 HOSA members dedicated to planning and running camp the first year.  One thing that really helped was meeting up a couple months in advance of camp for a 6 hour retreat. We spent several hours working, planning each day and breaking down jobs, but we spent the rest of the time playing, eating a potluck meal, making up nicknames for each other, playing Red Rover like kids.  It was a blast and we got so much accomplished!  And an awesome outgrowth of our silly nicknames game is that it brought us all closer and established a special bond between everyone.  Also, when camp started, everyone had puffy painted nicknames on the back of their camp shirts and we called each others by those names and campers had a blast trying to figure out all the counselors real names.

The first year of camp, the theme was Anatomy: We Know You From the Inside Out.  Camp cost $80/child for kids that pre-registered (by April) and $100 for late registration.  Camp was designed for kids entering grades 6-9, but a few kids going into grade 5 made special requests to come and we allowed it (same with one kid going into grade 10).

Camp from 9-2 pm every day, using the following schedule:

  • 9:00-9:30–check in, warm up icebreakers & games
  • 9:30-12:00–learning about the topic of the day, including a dissection
  • 12:00-1:00–lunch, with guest speaker each day
  • 1:00-2:00–review of day via games

Campers were divided into four different groups, based on age.  Each group had 7-15 kids and 1-2 counselors responsible for those campers.  Groups gave themselves silly names like “Nerdy Neurologists.” The counselor stayed with those kids every single day all day.  There were also 8 HOSA members who were Teachers and each had a subject to master and teach daily.  Those students stayed in the classroom in which they were teaching and taught the same concepts to a different group of kids each day, with the counselors present to help.  The themes were:

  • The Heart
  • The Eyes
  • Bones
  • Kidneys

Monday-Thursday all ran the same way, with the team that started Monday on the Heart rotating to the Eye Tuesday and the Monday Eye team rotating to the Bones, etc.  Friday was different.  We played games in the morning and in the afternoon parents were invited for an awards ceremony.  That’s when the kids received their t-shirts and the counselors gave each camper a special reward, based on something that kid was really good at or really loved.  We showed a slideshow from the week and had a big celebration.

Camp Biomed Full Group
The 2014 Anatomy Group

Camp went so well the first year, that we didn’t change much for year two.  We used a new theme, as we had many repeat campers.  Many of our HOSA members were really passionate about Forensics, so we went with a murder mystery theme.  Below is the flier we made to promote camp.

CB 2

We used much the same method of organizing camp and had a similar number of campers.  Kids loved the theme and the HOSA team had so much fun inventing mysteries for them to solve on the last day of camp.  The HOSA kids were the victims and the perpetrators and campers had to use forensic skills learned throughout the week to solve each mystery!

MM 6
The 2015 Murder Mystery Group

We are very excited to run Camp Biomed again this summer and hope to be hosting at least 60 kids to this year’s camp.  The theme is Camp Biomed: Where Fun is Contagious and it’s all about microbes and infectious diseases.

Have any questions about our fundraisers?  Awesome tips to share from your own experiences?  Please comment and share!

Heart Anatomy

What’s the size of 2 fists, beats 100,000 times per day and has been working since you were smaller than a gummy bear?  The coolest muscle in your body… YOUR HEART!

When teaching about the heart, I like to start by getting my kids interested with “Heart a Facts.”  Every kid looks up a unique fact about the heart and shares it with the class.

Here are a few examples of favorites:

  • Your heart beats ~100,000 times per day and sends 2,000 gallons of blood through the blood vessels each day.
  • Heart disease has been found in 3,000 year old mummies.
  • Your heart starts beating at 4-5 weeks, when you are smaller than a gummy bear

We then transition to the heart’s anatomy, working from the inside out.  Students complete an activity called “Draw the Heart,” in which they go through a PowerPoint and create a diagram of the heart’s interior anatomy to place in their journals.

Draw the Heart is a great start, but students need much more reinforcement to truly learn the flow of blood through the heart, so I follow it with several other activities.  The day after Draw the Heart I typically will have them draw a diagram showing blood flow through the body.  I walk them through it step by step, explaining each part of the diagram as we draw it.  I draw this on the blackboard or whiteboard, while the students draw it in their journals.  They also add notes on what the difference is between the role of the veins, arteries, chambers and valves.  We talk about etymology and important roots.  For example, pulmo- means lungs, so they can remember that the pulmonary arteries and veins connect to the lungs.  Atri- means receiving halls, so that’s a good way to remember that the atria receive blood.

Blood Flow

After doing the Blood Flow diagram, students write a paragraph explaining it to show they understand it.  They must write from the perspective of an RBC traveling through the body to deliver oxygen.  They have to name every chamber, vessel and valve they go through, as well as talking about visiting the lungs to get oxygen and visiting a part of the body to drop it off.  Below is an example of a student’s response.

“I’m a erythrocyte on my way to my friend fingertips. I’m starting in the Right Atrium and exit through the tricuspid valve into the Right ventricle. After I hang out there for a little I go out the pulmonary valve along the pulmonary arteries to my favorite windy spot, the lungs. I go shopping for a gift of a little oxygen and ride the pulmonary vein train to the Left Atrium, chill then keep it moving. I go through the bicuspid (mitral valve) to the old buddie Left Ventricle. Almost to my fingertips “ ON MY WAY BUDDIE!!” I exit the Left Ventricle through the aortic valve along the path of aorta to my friend fingertips. I give him my gift of oxygen stay and chat awhile before heading back to my start the Right Atrium entering through the lovely vena cavas.” –Krystalynn Shirley, Freshman

I’m a big believer in kinesthetic learning, so the next step for us (ha!  pun intended!) is to “Walk the Heart.” To prepare, I either tape a heart to the floor (not anatomically accurate) or draw it using chalk outside (if weather permits).  Students then take turns walking through the heart’s structures, announcing them as they go.  They pick up oxygen (red balloons) in the lungs and drop it off and pick up CO2 (blue balloons) as they pass through the body.

Billy You of Evansville Vanderburgh School Corporation has an incredible way of teaching blood flow.  Print out the images  below onto heavy white or cream-colored paper.

yarn pics

Have students color code the pictures as shown below and use a hole punch to punch the holes.  Have each kid measure out 1 meter of red yarn and 1 meter of blue yarn.  Then, have the students thread the yarn through the holes to show how blood flows.  Students can keep this in their journals as a reference.

yarn activity pic

After learning the internal structures of the heart, we very briefly go over the exterior structures of the heart (so much less interesting than the inside!) and they complete a diagram of the outside for their journals.  Again, I emphasize roots with them.  Apex comes from Latin meaning peak or tip, and that’s the point at the base of the heart.  Coronary comes from the Latin for wreath or crown, because it wraps around the heart.  We talk about the fact that when they dissect they’ll need to use the coronary artery to determine the front side of the heart and we also discuss the coronary artery’s role in nourishing the heart’s tissue.

Finally, the big day has come: Heart Dissection day!  Students work in teams of 2-4, depending on the number of hearts available.  I’ve never tried the next activity, but plan to.  My awesome colleague Alicia Harkins-Pritchett came up with the idea of drawing a heart on every team’s lab table with chalk markers and having the students draw the flow and label the structures as a pre-lab quiz.

The beginning of our heart dissection involves identifying the coronary artery in order to figure out which side of the heart is the front.  Students also identify the right and left sides and check it with me.  As best they can, they try to figure out which vessel is which, but that’s much easier once they’ve bisected it!  We typically use preserved sheep hearts, but if a student is able to bring in a fresh heart that’s amazing!  We’ve gotten a fresh deer heart from a student whose father hunts and a fresh cow heart from a family that purchased a whole butchered cow.  Some teachers are able to get all their hearts from a butcher, but I’ve never been so lucky.  I typically get mine from Carolina Biological, though hearts from NASCO are about $3 cheaper each and pretty decent quality too.

The next step is for the students to bisect the heart.  They should use a sharp scalpel and start at the apex, cutting up each side.  I encourage them to cut it enough to open it like a book, leaving the top of the heart intact so they can examine the vessels.

Students struggle far more with the internal anatomy than the external.  Even though they technically know that they separated the front from the back of the heart, they often get confused and start to think that they separated the left side from the right.  I check in with each team to make sure they are able to identify the left vs. right side and all 4 chambers.  I just have them point things out and label them on a paper diagram, but many teachers have them use toothpicks or even make little flags to label structures.  After ensuring that they know where the septum is and which side is which, we move to identifying the valves.  The mitral and bicuspid valve are the only ones I require them to identify.

I make sure they find the chordae tendineae and tug on them to move the valve.  I always bring up the phrase “tugging on my heart strings” and tell them these are the ACTUAL heart strings.  They love that part.  The Ryan Gosling meme is a fun reminder of this.

Finally, I encourage kids to probe the vessels with their fingers, pushing through each chamber to see where their finger emerges.  They use their blood flow diagram as a reminder that each chamber has one major vessel that connects to it, so if they know which vessel connects to each chamber, they can use the probing to figure out which vessel is which.

Heart Structure 4
Taylor is equal parts horrified and fascinated!

I love getting teaching ideas from others, so if you have other ideas of how to teach the heart, please share!  And if you try out any of these ideas, let me know how they work for you.  Just comment below to share.  I look forward to hearing from you!