Eyes and Vision Unit Study and Lesson Plan

This was a pretty short unit, and we have learned about some of these concepts before, in our Nervous System and Light and Optics Units. (And even way back in our Illusion Unit!) But it was a fun review, and we loved all the cool Optical Illusions books we got from the library!

The best part of our unit was visiting an optometrist's office. He is a homeschool dad, and he was wonderful at explaining to the children what he does and how all his cool equipment works. We loved it!

A couple other links of interest:

parts of the eye coloring page 

optical illusions

Motor and Sensory Neurons Body Tracing; Reflexes

I remember my brother Philip doing "body tracing" art in 5th grade---they just drew pictures of themselves wearing the clothes they were wearing, life-size. I thought it was SO cool. So, we decided to do the same here, but draw the internal view instead. :) We added two colors of yarn, one to represent the sensory nerve pathways going up toward the brain, and one to represent the motor nerve pathways coming back from the brain and spinal cord to direct muscle movement. We talked about interneurons and autonomic nerves too, but not everyone included those on his or her picture.

These pictures all turned out taller-than-life. Probably because the tracing was very, very difficult with such TICKLISH children. They couldn't hold still while being traced around (very gently, I might add!) to save their lives!

We also did some reaction time and reflex tests, as outlined in this video and this site, and of course we hit our knees with my drumsticks a lot, to test our reflexes. We love doing that.

Seb got really complicated with his. As you can see, his finger has just touched a candle flame, so he's got some reflex action going on as well.

Daisy was just happy to be included (I love how she drew her eyes and mouth on top of her brain)

Junie just got a picture, no nerve pathways. My goodness that drawing is alarming! Sam said it was because she colored her eyes yellow, but I think it has more to do with how I drew her face. *shudder*

Malachi "really just LOVES the digestive system" (his words) (??) and so wanted to include the autonomic nerves and some internal organs.

Seb + Seb

Spinal Cord model with egg carton and licorice

I found lots of ideas for spinal cord models (this one made with a pool noodle is cool, and I liked this one with gummy rings too), but since we still had licorice from our neuron models, and since I liked the idea of having the spinal cord be thick and tough, yet flexible (rather than just represented by a piece of string as it is in the models linked above), we settled on this egg carton/licorice model.

What you need:

An egg carton to cut up, for the vertebrae

Craft foam (or something kind of spongy), for the vertebral discs

Licorice, for the spinal cord

I chose to use egg carton sections because they really do look quite like vertebrae. We tried both ways: poking holes through the bottom of the egg carton section (Abe's was made like this) and poking holes through the side of the egg carton as shown above. I think I preferred the latter way just because of how it looked, but both ways are fine.

Then you just thread the vertebrae onto the spinal cord, alternating with the discs.

We really liked the way the licorice spinal cord allowed flexibility and movement of the spine. They were fun to play around with.

Sheep Brain Dissection

We got a chance to see a lot of the structures we'd learned about when we dissected this sheep's brain! I got it here (totally worth getting the kit as opposed to just the brain, as it comes with a disposable scalpel and I would have DIED if I had to use one of my kitchen knives!), and it said they used some improved process of preservation so the formaldehyde smell wouldn't be so strong, but, formaldehyde is formaldehyde I guess. Whew. It is not a smell I enjoyed being reminded of; it brings back fetal pig dissections and cadaver labs from my high school days, which I was always interested in but also sick to my stomach during. However! We are made of sterner stuff these days, so we soldiered on. Abe did the honors:

while the rest of us looked on with great interest.

That dura mater really is durable! It was hard to slice through.

We were excited to observe so many of the things we'd seen in books, including the clear difference between grey and white matter,

And several of the inner structures. The cerebellum is my favorite. It's so neatly lined and cauliflowery!

Brain hats (cerebral cortex)

We loved making this brain hat (UPDATE: if that link won't work for you, try this: Go to the link here: https://ellenjmchenry.com/ and go to "Free downloads--> Human Body". Then scroll down and under "brain" you will see a link for "brain hemisphere hat." Hope that works for you!) while we talked about parts of the brain! It just shows the functions of the cortex (we covered internal structures separately) but we made it early on in the unit and referred to it often throughout.

The hats were easy to make. Just print and cut out and tape together. Download is here.

When we talked about the parts of the brain, we also did this activity that shows the importance of the cerebrospinal fluid, the meninges, and the skill. Also what happens when you get a concussion! :)

Ooh, and while we're on the subject of brain hemispheres, you really should watch this video from The Happy Scientist of "Kneesy Earsy Nosey." First watch this from Laurel and Hardy, then watch the Happy Scientist explain why it's so hard to cross the midline! We all resolved to get good at doing this, but none of us have (yet). :)

More brain structures (I told you my children liked diagrams)

Wondering why my children always seem to be dressed as animals? They just . . . are.

This was Junie's magnum opus. She spent an hour coloring it so neatly. I quite like it.

Since the hats have since been thrown out, I promised the children I would post pictures of every single precious one. :)

Neurotransmitters

I've always thought neurotransmitters were so cool---what a clever way to transmit electrical impulses across what is, essentially, a repeatedly-broken circuit, right? We watched the animations on this page

and read some good explanations about neurotransmitters here and the action potential here. We drew lots of diagrams (because my kids like diagrams).

Bees vs. Wasps, and Stingers

Abe's drawing

Thanks to several books and websites, we now finally know the difference between a bee and wasp. Hooray! The children drew pictures showing the distinctions between them.

I was pretty impressed with Daisy's!

Malachi's drawing

Sebby's drawing

This was a little demonstration just showing how bee stingers and wasp stingers (and queen bee stingers) differ from each other. Worker bee stingers are barbed, kind of like the screw at left above. Queen bees and wasps have smooth stingers, more like the nail.

To show how the two stingers act in different materials, we poked them into cardboard and stryofoam. The barbed stinger and the smooth stinger both pull out pretty easily from cardboard (though the barbed one leaves a bigger hole). The cardboard is like another insect's exoskeleton. Thus, worker bees, queen bees, and wasps can all sting other insects without harm to themselves. 

The stryofoam is like the softer flesh of a mammal. When the smooth stinger pokes into a mammal's flesh, it can pull out again. But when the barbed stinger enters a mammal, it sticks inside and the barbs keep it in place. Thus, when the bee flies away after stinging a mammal, the stinger rips from her body, eventually killing her.

Here is a nice picture of a bee's stinger.