Cow Eye Dissection
COW EYE DISSECTION
Use the following link to watch a video on a cow’s eye dissection. http://www.exploratorium.edu/learning_studio/cow_eye/video_sm_all.html Aim: The purpose for a cow’s eye dissection is to learn the different parts of the eye by doing a hands on experiment. You can always see the eye from images or diagrams, but this experiment helps you get a better visual and feel of an eye.
Materials: * Scalpel * Scissors * Newspaper * Cows eye
Method:
1. Examine the outside of the eye. You should be able to find the sclera, the tough, outer covering of the eyeball. In humans, the sclera is the whites of the eyes, on a preserved cow eye; this area may appear dark brown. You should also be able to identify the fat and muscle surrounding the eye. Locate the covering over the front of the eye (the cornea). When the cow was alive, the cornea was clear. In your cow’s eye, the cornea may be cloudy or blue in colour.
2. Cut away the fat and muscle, this may only be necessary if fat is covering the cornea of the eye and is in your way. Fat around the backside of the eye can be left alone. Flip the eye over to find the optic nerve where it exits out the back of the eye. It will be stronger and more rope-like than the surrounding fat tissue.
3. Use a scalpel or scissors to make an incision in the cornea. The cornea is tougher than it appears and may require some force to puncture, be careful when using the scalpel. Once the cornea is broken, clear liquid will leak (or squirt) out – this liquid is the aqueous humor. Quick Check: Outer Tunic
A. The white of the eye is the cornea.
B. The front surface of the eye, continuous with (A) is the iris.
C. The liquid found in the front of the eye is the aqueous humor.
4. Use a scalpel to make an incision in the sclera so that you can cut around the outside of the eye. Scissors may also be used. Your goal is to separate the eye into a front and a back half.
5. Separate
Use the following link to watch a video on a cow’s eye dissection. http://www.exploratorium.edu/learning_studio/cow_eye/video_sm_all.html Aim: The purpose for a cow’s eye dissection is to learn the different parts of the eye by doing a hands on experiment. You can always see the eye from images or diagrams, but this experiment helps you get a better visual and feel of an eye.
Materials: * Scalpel * Scissors * Newspaper * Cows eye
Method:
1. Examine the outside of the eye. You should be able to find the sclera, the tough, outer covering of the eyeball. In humans, the sclera is the whites of the eyes, on a preserved cow eye; this area may appear dark brown. You should also be able to identify the fat and muscle surrounding the eye. Locate the covering over the front of the eye (the cornea). When the cow was alive, the cornea was clear. In your cow’s eye, the cornea may be cloudy or blue in colour.
2. Cut away the fat and muscle, this may only be necessary if fat is covering the cornea of the eye and is in your way. Fat around the backside of the eye can be left alone. Flip the eye over to find the optic nerve where it exits out the back of the eye. It will be stronger and more rope-like than the surrounding fat tissue.
3. Use a scalpel or scissors to make an incision in the cornea. The cornea is tougher than it appears and may require some force to puncture, be careful when using the scalpel. Once the cornea is broken, clear liquid will leak (or squirt) out – this liquid is the aqueous humor. Quick Check: Outer Tunic
A. The white of the eye is the cornea.
B. The front surface of the eye, continuous with (A) is the iris.
C. The liquid found in the front of the eye is the aqueous humor.
4. Use a scalpel to make an incision in the sclera so that you can cut around the outside of the eye. Scissors may also be used. Your goal is to separate the eye into a front and a back half.
5. Separate