FIELD TRIPS : SCIENCEWORKS LAB : Cow Eye Dissections

Investigate how the eye works by dissecting a real cow eye. Students connect the functions observed to the structures within the eye.

Additional materials fee: $30 per class.

Michigan Grade Level Content Expectations, Science, 2007

• Design and conduct scientific investigations. (S.IP.05.12; S.IP.06.12; S.IP.07.12)
• Describe the physical characteristics (traits) of organisms that help them survive in their environment. (L.EV.05.12)
• Relate degree of similarity in anatomical features to the classification of contemporary organisms. (L.EV.05.21)
• Recognize that all organisms are composed of cells (single cell organisms, multicellular organisms). (L.0L.07.21)
• Explain how cells make up different body tissues, organs and organ systems. (L.0L.07.22)

Cow Eye Dissections Pre-visit Materials

During Your Visit to the ScienceWorks Lab students will be expected to:

• Sit in tables of 6 students and (at least) 1 adult
• Students should be prepared to give their attention to the Lab instructors when requested to “Give Me Five”
• Work cooperatively with one another at the table
• Follow the hands-on procedures just as the Lab teacher or assistant explains them
• Handle materials and equipment carefully

It is important that teachers and chaperones:

• Help to focus the students’ attention
• Assist students with the hands-on activities and experiments when necessary
• Turn off cell phones and pagers during the class

Please Note

• Students will be expected to work in pairs to dissect a real cow eyeball and briefly use a razor
• Students will be expected to carefully follow the safety procedures for dissections

Vocabulary

Aqueous Humor: A clear fluid that helps the cornea keep its rounded shape

Blind Spot: The place where all nerves from the retina join to form the optic nerve. Each eye has a blind spot where there are no light-sensitive cells.

Cornea: A tough, clear covering over the iris and the pupil that helps protect the eye. Light bends as it passes through the cornea; the cornea begins bending light to make an image.

Iris: A muscle that controls how much light enters the eye. It is suspended between the cornea and lens. A cow’s iris is always brown, while human irises may be brown, blue, green or gray.

Optic Nerve: The bundle of nerve fibers that carry information from the retina to the brain.

Pupil: The dark circle in the center of your iris. It is a hole that gets bigger or smaller, as the iris expands or contracts, to let light into the eye.

Retina: The layer of light sensitive cells at the back of the eye. The retina detects images focused by the cornea and the lens. The retina is connected to the brain by the optic nerve.

Tapetum: The colorful, shiny material located behind the retina which is found in animals with good night vision. The tapetum reflects light back through the retina to enhance the animal's night vision.

Vitreous Humor: The thick, clear jelly that helps give the eyeball its shape.

Cones: One kind of light-sensitive cells in the retina. Cones give you color vision in bright light.

Rods: One kind of light-sensitive cells in the retina; they work in dim light.

Cow Eye Dissections Post-visit Activity

Post-visit activities will help reiterate new concepts and tie the ScienceWorks Lab experience to your classroom curriculum. Below you will find a classroom activity and a list of suggested resources for further information. We hope that you enjoyed your field trip. Visit us again!

Suggested Resources

Books

tbd

Internet