Sheep’s Eye Dissection Inside & Out:

1. Sheep’s Eye DissectionInside & Out: Taking a Closer Look

2. Learning Target: Anatomy and Physiology of the Eye I Can…Compare and contrast the structures of a sheep’s eye to that of a human eye and describe the structure and function of the components of an eye. • I Will… • Dissect a preserved sheep’s eye; • Identify the external structures of the eye • Describe the function(s) of each structure • Identify the internal structures of the eye • Describe the function(s) of each structure • Create a side view diagram of a human eye with appropriate labels

3. Materials: 2-person lab group 2 2 Lab Instructions & PowerPoint Guide

4. Learning Target: Anatomy and Physiology of the Eye External Anatomy: • Sclera • Tough white outer covering of eye that protects internal structures of eye • Cornea • Clear extension of sclera in front of the eye that allows light to enter the eye

5. Learning Target: Anatomy and Physiology of the Eye External Anatomy: • Optic nerve • Carries information from the eye (retina) to the brain (Occipital lobe) • Fatty tissue • Surrounds the eye to cushion and protect it from damage • Eye muscles • Attach firmly to the eye and pull on the eyeball causing it move

6. Learning Target: Anatomy and Physiology of the Eye Internal Anatomy: • Vitreous humor • Clear jelly-like substance • Helps hold shape of the eye • Clear to let light through • Jelly not solid so wont crack or break • Retina • Lines the back of the eye • Location of photoreceptors • Cones – detect color (RGB) • Rods – detect light/dark (greys)

7. Learning Target: Anatomy and Physiology of the Eye Internal Anatomy: • Blind spot/Optic disk • Point where retina leaves to become optic nerve • No photo receptors located there. • Tapetum • Located behind retina • Shiny and reflective • Helps animals to see in low light • NOT found in human eyes

8. Learning Target: Anatomy and Physiology of the Eye Internal Anatomy: • Lens • Round, biconcave clear disk • Focuses light onto retina • Held in place by suspensory ligament • Ciliary muscles • Adjust shape of lensto focus at different distances • Short & fat • Long and thin

10. Learning Target: Anatomy and Physiology of the Eye Internal Anatomy: • Iris • Colored area in front of the lens • Pupil • Clear opening in iris that allows light to enter eye • Size controlled by two sets of muscles in iris • Constriction – smaller • Dilation – larger • Controls amount of light

11. Learning Target: Anatomy and Physiology of the Eye Human Eye References Eye Dissection. (n.d.). Eye Dissection. Retrieved May 15, 2013, from http://science.jburroughs.org/resources/skeleton/eye/eyedissection.html

12. Learning Check: Anatomy and Physiology of the Eye I Can…Compare and contrast the structures of a sheep’s eye to that of a human eye and describe the structure and function of the components of an eye. • I Will… • Dissect a preserved sheep’s eye; • Identify the external structures of the eye • Describe the function(s) of each structure • Identify the internal structures of the eye • Describe the function(s) of each structure • Create a side view diagram of a human eye with appropriate labels