Presentation on theme: "Do Now Research the following diseases and give a sentence summarizing them Glaucoma Conjunctivitis “Floaters” Corneal Abrasion Astigmatism Night vision."— Presentation transcript:
1 Do NowResearch the following diseases and give a sentence summarizing themGlaucomaConjunctivitis“Floaters”Corneal AbrasionAstigmatismNight vision blindness
3 Objectives To identify different visual accessory organs. To compare and contrast rods and cones.To explain various diseases of the eye.
4 Accessory Organs of the Eye Eyelids: contain skin, muscle, connective tissue, and conjunctiva.Main Eye Muscles:Orbicularis Oculi: closes lid upon contraction.Levator Palpebrae Superioris: opens lid
5 Accessory Organs of the Eye Conjunctiva: mucous membrane lining eyelids and anterior surface of eyeball (except the cornea)Lacrimal Apparatus:Lacrimal gland- secretes tearsSuperior and inferior canaliculi- collect tears*Tears contain lysozyme which acts as an antibacterial agent.
6 “Conjunctivitis”Inflammation of the conjunctiva. Can be causes by a viral infection or an allergic reaction. Most commonly caused by bacteria which people call “Pink Eye”
7 Accessory Organs of the Eye Extrinsic Eye Muscles:Superior RectusInferior RectusMedial RectusLateral RectusSuperior ObliqueInferior Oblique
8 Accessory Organs of the Eye Extrinsic Eye Muscles:
9 Eye Structure*The eye is about 2.5cm and is hollow It contains 3 layers 1) An outer fibrous layer 2) A middle vascular layer 3) Inner nervous layer
10 Outer Layer Cornea: Sclera: (the white part) focuses entering light raysMade of connective tissue + epitheliumAvascularSclera: (the white part)Collagenous + elastic fibersProtects eyeProvides a place for muscle attachment
11 Middle Layer Choroid coat: Ciliary Body: Lens: Provides blood vessels Contains melanocytesCiliary Body:Aids in focusingHolds lens in placeLens:Changes shape to focusFlat=focus on distanceConvex=focus on close objects.
12 Middle Layer Iris: Pupil: Aqueous Humor: Colored part Contains muscles that control pupil sizeDivides anterior/posterior chambersPupil:Opening in the irisAqueous Humor:Watery fluidSecreted between cornea and lensProvides nourishment
13 “Glaucoma”Excessive production of aqueous humor causes pressure on the blood supply from the optic nerve which deprives cells of oxygen causing them to die and the patient to become blind.
14 Inner Layer Retina: Optic Disc: (“Blind Spot”) Viterous Body: Contains photoreceptorsOptic Disc: (“Blind Spot”)Contains nerve fibersContains central arteries and veinsLacks receptorsViterous Body:Maintains shapeNourishes the posterior cavity
15 “Floaters”Bits of vitreous humor clump and cast shadows on the retina which causes “floaters”. They can be seen most commonly when looking at the sky or a blank wall. Do YOU have floaters?
16 Do Now What is the colored part of your eye called? The white part? What holds the lens in place?Where are photoreceptors located?What part of the eye does glaucoma effect?
17 Objectives Explain different diseases associated with the eye. Identify different parts of a cow eyeball through dissection.Perform various eye tests to observe different functions and capabilities of the eye.
18 Light RefractionLight waves enter your eye and your lens focuses and “bends” the light, projecting the image on your retina
19 Visual Receptors The eye contains modified receptors in the retina Rods: black and whiteCones: color (3 types)
20 “Color Blindness”The person usually lacks one of the 3 types of cone receptors causing them to have trouble distinguishing reds and greens.
21 “Night Blindness”A deficiency in Vitamin A reduces production of retinal which is necessary for rod sensitivity and seeing at night.
22 “Astigmatism”Curvature of the eye is incorrect and causes blurriness or distorted vision
23 Lab- Cow Eye Dissection Gather all materials necessary for the dissection.YOU MUST WEAR GOGGLES, AN APRON, AND GLOVES!!!!Complete the dissection as instructed in the lab handout and be sure to show me the pinned structures for points!