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Substitute Teacher. Dr. Whittaker Chemist PhD, scientist with IBM and Pfizer Subbed for a year in Wake County Schools I do not have SPAN or Blackboard Access I will have Ms. Ewing post these PowerPoint presentations. Warm Up. Keep in your notebook on separate pages.
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Substitute Teacher • Dr. Whittaker • Chemist PhD, scientist with IBM and Pfizer • Subbed for a year in Wake County Schools • I do not have SPAN or Blackboard Access • I will have Ms. Ewing post these PowerPoint presentations
Warm Up • Keep in your notebook on separate pages. • Turn in on the day of the next test. • What are the effects of the sympathetic and parasympathetic nerve response on the iris and ciliary muscles?
Warm Up Discussion • What is sympathetic and parasympathetic responses? • Sympathetic: Response to tense situation. • Parasympathetic: Happens when not threatened. • What are the two systems & how do they respond • Iris: Sympathetic; Dilates pupils • Parasympathetic; Constricts pupils • Ciliary muscles: Symp. Inhibits to improve distance sight • Para. Stimulates for close vision
What are the 5 senses? • Two types of sense receptors. • Why is vision key • Most studied • Most receptors and most complex system • 25% will suffer major low vision as they age • 75% adults have corrected vision (Vision Council of America) Special Senses The Eye and Vision
Anatomy of the Eye Page 241 … Figure 8.1
How does the eye work? • What does the Iris do? • What does the Cornea do? • What does the Lens do? • What does the Retina do?
Eye Protection • Jot down as many functions that protect the eye that you can think of: (I have 6) • Bone of the orbit • Fatty tissue • Eye lashes • Eye lids • Meet at the medial and lateral canthus • Eye brows • Moisture/Lubrication/Antibiotics & Lysozymes • Tears • Lacrimal apparatus • Glandular • Lubrication from meibomian and ciliary glands • Conjunctiva
The Eyeball • Three Tunics or Layers • Sclera • Choroid • Retina • Scary (Sclera)Cadavers (Choroid)Run! (Retina)
Retina One photon of light Cascade chemical Electrical Impulse Sent to brain via optic nerve Rods 75 – 150 x 106 Low Light .. B/White Cones 7 x 106 Daytime .. Color Key Regions Blind Spot Macula (temporal to blind spot) Fovea most sensitive
Photoreceptors • Man has 3 types of cones • Most mammals have 2 (no red) • Some animals have 4 (+ UV)
discussion What is the problem with the mammals backwards visual receptor?What is an advantage of the backwards design?
Humor Me • Aqueous Humor – before the lens • Vitreous Humor – Inside the eyeball.
If the pressure is too high. Glaucoma Leads to blindness
Problems with the Eye Tomorrow