Nervous System PNS. Incredible Human Machine SIGHT HEARING.

Human Eye

Nervous SystemPNS

Incredible Human Machine SIGHT

https://www.youtube.com/watch?v=JddHE5l0y68

HEARING (6:09)https://www.youtube.com/watch?v=JddH

E5l0y68 SMELL (8:28)

https://www.youtube.com/watch?v=9MDn5GgyxyU -

External Anatomy See p.281MUSCLE Turns

EYE…Controlled by…

1. SUPERIOR RECTUS

Superiorly (up)

III Oculomotor

2. INFERIOR RECTUS Inferiorly (down)

III

3. LATERAL RECTUS Laterally (to side)

VI Abducens

4. MEDIAL RECTUS Medially (towards center)

III

5. SUPERIOR OBLIQUE

Inferiorly & laterally

IV Trochlear

6. INFERIOR OBLIQUE

Superiorly & laterally

III

Internal Anatomy See pp. 281-284Eye part Class Notes Textbook

Notes

1. Sclera The “white” of eye (:

2. Cornea Most anterior part of the sclera – your “window” to the world

3. Lens Refracts light

4. Iris Pigmented “diaphragm” of eye

5. Ciliary body Contains muscle that controls the shape of the lens

6. Ciliary zonule

Attaches the lens to the ciliary body

7. Aqueous humor

Fluid in the anterior segment that provides nutrients to the lens and cornea

Eye Part Class Notes Textbook Notes

8. Vitreous humor

Gel-like substance that helps reinforce the eyeball

9. Cones & Rods

Photoreceptor cells in the retina; CONES = daylight & color / RODS = dim light

10. Retina Layer containing the rods & cones at the back of the eye

11. Choroid Nutritive (vascular) layer of the eye

12. Fovea centralis

Area of acute vision; a dimple in the retina where cones are concentrated

13. Optic disk “BLIND SPOT”; Area of retina that lacks photoreceptors

14. Canal of Schlemm

Drains the aqueous humor of the eye

Colorblindness TEST

http://colorvisiontesting.com/ishihara.htm

What causes colorblindness???

Can you read thenumbers in each circle???

Homeostatic Imbalancesof the EYE

Disorder Cause Effect

Night blindness (p. 284)

Skip 4 lines

Color blindness (p. 284)

Cataracts (p. 286)

Glaucoma (p. 286)

Strabismus (p. 301)