Human Body - Day 9

Today was dissection day!!  If you have a weak stomach, you might want to pass on the pictures.  It wasn't as bad as I thought.  Nicolas (our gaggy one) could not watch while we were cutting, but once the piece was there to look at, he was fine.  We bought a cow's eye to dissect.  This helped us (me included!) tremendously to understand how our eyes are put together.  Still don't completely understand HOW it works, but at least we know what the inside of the eyeball really looks like.  Diagrams just can't effectively show us.  When the dissection was complete, it made it MUCH easier to fill out the diagram of the eye that we added to our lapbook.  Okay, now for the pictures.

The greyish material around the edges are the tissue and muscles.  If you look in the middle at the black X - that is the optic nerve.

So we began by cutting the tissue and muscle off from the schlera (the white of the eye.)  The coloring has changed because it's dead. :)

Next we cut the cornea from the eyeball.  This revealed the iris (the dark in the middle).  The hole in the middle of the iris is the pupil.  We were able to see that the iris can get bigger and smaller to let in more light.

The next step was cutting the eyeball in half.  This revealed a jelly like substance that fills the inside of the eye.  The left half is the front of the eye and the right is the back.  You can see the optic nerve still.

We popped the lens out.  This works as a magnifier.  We are able to see that in the word "hello" printed on a piece of paper.  You can see the 'e' and part of the 'l' is quite larger than the 'o'.  The lens was hard and like a marble, but in a live eye, it is soft.

Finally we look at the inside of the back half of the eye.  The cream colored part is the retina.  If you look at the top-right , you can see where the optic nerve comes in to the retina.  This is the only place the retina is attached to the eye.  We slid the retina down to reveal the irridescent blue.  This is what reflects light into the retina.  In animals, it is more shiny than human.  This is why animal's eyes seem to glow at night.  I have forgotton all the technical terms for these parts and am too lazy to get up and look them up.  I'm not sure we're ready for too much more dissecting at this point, but this was a fun learning experience for us.  (And it didn't smell too bad.  It had a smell, but didn't stink.)