Body Systems: Nervous System: Brain Model

The human brain, at full-size,  is about the size of a full sheet of newspaper (or a pillow case), that's folded up to fit in your skull.

Keep your eyes open for a sheet of newspaper that has a full page ad that has some writing, but a large white space.  When you're born, your brain already has a lot of information stored in it, represented by the writing on the page.  But there's also a lot of room to learn more.  That's the white space on the paper - the brain space that's left to "write" on.
 
It's difficult to put numbers on how "full" one's brain is at birth and how much "room" there is for future learning, as the more you learn the more connections your brain makes.  It appears that there's always room for more learning to take place and that the brain is never "full" (to our current knowledge). 

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Sound: The Clanging Hanger

This is a simple demonstration that helps make the point that sound needs something to travel through and that air is not a very efficient material for that purpose.

You only need a wire coat hanger and a long length of string.

Tie the string onto the hanger, so that the hanger hangs from the middle of the string.

Swing the hanger from the string so that it bumps into something (a table, chair, wall, etc.) and take note of the sound it makes.  It's kind of a short, clang-y sound.  Nothing very dramatic or melodic about it.

Now, wrap one end of the string around one of your index fingers and the other end around the other index finger.

Place your fingers in your ears (gently, there's no need to jam them in).

Swing the hanger so that bumps into something once again and take note of the sound it makes.  Louder and more like a gong or large bell ringing.

In the first trial, the sound made when the hanger hit the object had to travel through the air to reach your ear drum.  A lot of the sound was lost on the way to your ear.  In the second trial, the sound vibrations travel from the hanger through the string and your fingers to your ear.  Much less sound energy is lost in route and it makes an audible difference. 

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Body Systems: Nervous System: The Importance of Cerebrospinal Fluid

Cerebrospinal fluid (CSF) is the liquid that surrounds your brain and prevents your brain from smashing in to your skull. 

Here's a simple little demonstration that shows just how crucial that fluid is.

You'll need a small container (with a tight-fitting lid), 2 eggs and some water.

Throughout the demonstration, the egg yolk will represent your brain and the container will represent your skull.

Crack one egg into the container and put the lid on. 

Agitate the container - you can just shake it, or you can have a student run a few laps around the room with it for it.

Open the container and observe - scrambled brains!

Clean out the container and crack the second egg into the container. 

This time, before putting on the lid, fill the remaining space in the container with water. 

Agitate the container once again.

Open the container and observe - the egg yolk remains intact.  (The egg what froths up a little bit, making it difficult to see at first, but the whole yolk is there).

The water cushions the egg yolk, just as the CSF cushions your brain. 

Great visual explanation!

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Jello Brain Update!

Remember the free Jell-o brain molds I told you about? 

Well, they arrived a couple of weeks ago. 

For size comparison - that's a 5 year old head it's next too (albeit a rather large 5 year old head....)

I haven't put mine to use yet (have to remember to get more Jell-o at the grocery store...), but my friend Susan got hers and tried it...


Photo from Susan at Learning ALL the Time



Fun stuff! 

If you're interested, you have through Monday (October 31) to get a free mold (only pay $2.95 shipping and handling).  After Halloween, it's regularly priced - $2 + Shipping. 

If you'd like one, head to the Kraft Corner Store!  You'll have a head start on next Hallween, and some interactive Central Nervous System lessons in the meantime!

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How Much Does Taste Depend Upon Smell?

Ever noticed that food doesn't seem to have as much flavor when you have a stuffed-up nose? 

A large part of your taste sensations come from smell, so when you can't smell very well, your sense of taste declines as well.  I've used Dum-Dum lollipops for this experiment, since they come in a multitude of flavors and we always seem to have a large number of them around the house after Halloween!

Have students work in pairs to do this experiment.

One student, the taster, closes her eyes and uses one hand to plug her nose.  The other student, the assistant, will then unwrap a randomly chosen lollipop.  He then hands it to the taster, who puts it in her mouth, while keeping her eyes closed and nose plugged.  The taster tries to identify the flavor of the lollipop.  The assistant records the taster's hypothesis. 

After making an initial hypothesis, the taster is then allowed to unplug her nose.  She tries again to identify the flavor of the lollipop.  Again, the hypothesis is recorded by the assistant.

And finally, the taster can open her eyes to view the lollipop, and make any final changes to her flavor guess. 

At that point, the flavor of the lollipop can be revealed and the two students can switch positions.


Of course, you don't have to use lollipops - any candy that comes in multiple flavors will work.  An experiment was put together as a follow-up to a Newton's Apple episode, in which jelly beans are used.  Check out the experiment, the explanation, and make sure you read the "Try This" suggestions at the end - I think I want to try the potato and apple experiment!

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Body Systems: Nervous System: FREE Brain Mold

Looking for a fun prop for your Central Nervous System lecture?  Or a little Halloween fun? 

Jell-O/Kraft Foods is giving away free brain molds (you pay $2.95 for shipping). 

As previously mentioned, Education Innovations sells a brain mold with instructions for making a gelatin model the same size and mass as a human brain. 

I don't know how the free mold compares in size - I doubt it has the accuracy of the Educational Innovations model, but it's free!  It could certainly be useful for pointing out the parts of the brain in a basic anatomy lesson.  And, assuming you can find a bike helmet in which it fits appropriately, you could use it for a lesson in bike safety and the importance of helmets.  (Drop one gelatin brain without a helmet and another in a helmet and compare the damage).

I've ordered a free one and will do some experimenting with it once it arrives.  I'll keep you posted.  In the meantime, go here to get yours. 

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