Wednesday, April 2, 2014

Science Class

Sarabeth and Christopher recently got to dissect cows' eyes in science class at Friday Addition, their homeschool enrichment program. The moms were recruited as lab assistants by the science teacher, so guess who ended up actually doing most of the handling and cutting?

As the big day approached, Sarabeth was pretty sure this dissection plan was the most horrific idea she'd ever been exposed to. She wanted to be released from the class and was quite surprised when I refused to excuse her. Christopher wasn't as adamant in his opposition, but he was also very reluctant.

When the day arrived, both children were fully prepared to be offended, disgusted, and grossed out. They both insisted they would not participate in the dissection. As one of the official dissectors, I wasn't sure how I would feel about it either, but I calmly put on a brave face.

In the end, the dissection was so cool! Cows' eyes are very similar to human eyes, so the children were able to see firsthand what the different parts of a human eye are. After initially leaning back in their seats and shielding their eyes, Sarabeth and Christopher both ended up finding themselves fascinated with the cow's eye, begging to do some of the cutting, and confidently holding and manipulating the various eye parts so they could look at them close up.

A fantastic learning experience on so many levels... and the children even brought an eye home to show Daddy.

Christopher... all ready to explain everything to his daddy

Our cow's eye parts, on their official scientific dissection plate

The cornea  -- scratched up by our scalpel to demonstrate
how tough and protective the cornea is for the cow

The iris...
...and the hole in the center is the pupil --
Human pupils are round, but cows' pupils are oval.

The lens (which rests in the clear, jelly-like vitreous humor,
which had evaporated by the time we got home)

The retina (the white stuff) covers the entire back of the eye in a thin,
smooth layer. (Ours got a little "detached.") In the back of the eye, the retina
connects with the optic nerve, which takes the image information to the brain and tells you what you're seeing.
Or something like that....

The eye ball -- We first cut the top, to get to the cornea and iris.
Then we cut through the center of the eye ball to get to the rest of the parts.

The muscles and fat that surround the eye ball and the optic nerve.
A cow's eye has four muscles, whereas human eyes have six muscles. 





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