Transcript Eye Dissection

Eye Dissection
NAME: _________________ Period: ____
The white part is the ________, the
outer covering of the eyeball. The blue
is the _______, which starts out clear
but becomes cloudy after death.
• Without moving your head, look up. Look down. Look all around. Six
muscles attached to your eyeball move your eye so you can look in
different directions Cows have only four muscles that control their
eyes (superior and lateral recti). They can look up, down, left, and
right, but they can’t roll their eyes like you can.
• Now we are going to cut through the sclera and divide
the eye in half, right around the middle. The cornea will
be on the front half of the eye. The cornea is made of
many layers of tissue.
•
•
If you look at your eye in a mirror, you’ll see a colored circle with a black
spot in the middle. The colored circle is the ________. The black spot in the
middle of the iris is the ___________, a hole through the iris that lets light
into the eye. In dim light, the pupil __________, letting lots of light in.
The next step is to pull out the iris. The iris is between the cornea and the
lens. It may be stuck to the cornea or it may have stayed with the back of
the eye. Find the iris and pull it out. It should come out in one piece. You
can see that there’s a hole in the center of the iris. That’s the pupil, the hole
that lets light into the eye. The iris contracts or expands to change the size
of the pupil. In dim light, the pupil opens wide to let light in. In bright light,
the pupil shuts down to block light out.
• Here is the back half of the eye. With the cornea and the
iris out of the way, you can see the _______. It looks
gray in this photo, but it’s really clear. The clear goo
around the lens is the _________ _________. The
eyeball stays round because it’s filled with this clear goo.
• Here, the _______ works like a magnifying glass,
making the words look bigger. The lens of the cow’s
eye (like the lens of your eye) is shaped like the lens
of a magnifying glass. It’s thicker in the middle than it
is at the edges. This is called a _____________
lens.
• Here’s the back of the eye with the lens and vitreous
humor removed. It’s shaped like a bowl. On the inside of
the bowl is a thin film with red blood vessels running
through it. The _________ contains light-sensitive cells
that detect light.
• Here’s the inside of the back of the eye again. Behind
the retina is a layer of shiny, blue-green membrane
called the tapetum. This layer assists night vision by
reflecting light back through the retina. You don’t have a
tapetum, but cats and cows (and other animals) do. A
cat’s eyes shine in the headlights of a car because of the
tapetum.
Label the parts of the EYE
Name the parts
1. ____________ 2. ____________ 3. _____________ 4. _______________
5. ____________ 6.
N/A
7.
N/A
8.
N/A
9. _____________ 10. ____________ 11. ___________ 12. ____________