Visio GPC遠(yuǎn)景預(yù)測(cè)

1、07 nov. 2012vision-lab.ppt1vision eye converts electromagnetic radiation (light) to action potentials impulses carried over optic nerves & optic tracts to primary visual cortex07 nov. 2012vision-lab.ppt2eye: accessory structures eyebrow eyelids eyelashes07 nov. 2012vision-lab.ppt3eye: accessory

2、structures orbicularis oculi muscle closes eye conjunctiva mucous membrane under lid and over surface of sclera07 nov. 2012vision-lab.ppt4eye: accessory structures lacrimal apparatus lacrimal gland excretory ducts lacrimal punctum lacrimal canal nasolacrimal duct07 nov. 2012vision-lab.ppt5eye: extri

3、nsic musclessix muscles aim each eye superior rectus inferior rectus medial rectus lateral rectus (abducens) superior oblique (trochlear) inferior oblique07 nov. 2012vision-lab.ppt6eye three layers (tunics) fibrous tunic sclera cornea vascular tunic choroid ciliary body iris sensory tunic = retina07

4、 nov. 2012vision-lab.ppt7eye anterior segment aqueous humor secreted by ciliary body drained through scleral venous sinus (canal of schlemm) posterior segment vitreous humor07 nov. 2012vision-lab.ppt8eye: refraction cornea more refraction fixed (not focusable) lens connected to ciliary body by suspe

5、nsory ligaments changes shape to focus flatten for distance thicken for near vision07 nov. 2012vision-lab.ppt9focusing, accomodation lens changes shape to focus flatten for distance thicken for near vision07 nov. 2012vision-lab.ppt10regulating light intensity bright light stimulates parasympathetic

6、reflex to constrict pupils dim light stimulates sympathetic reflex to dilate pupils atropine (norepinephrine mimic) used to dilate pupils07 nov. 2012vision-lab.ppt11eye sensory tunic = retina extension of brain optic disc attachment, origin of optic nerve central artery & vein macula lutea &

7、 fovea centralis07 nov. 2012vision-lab.ppt12eye: retina retina built “backwards” light passes through 3-4 layers of cells before reaching photoreceptors retinal cells ganglion cells cell bodies of optic nerve fibers bipolar cells rods cones07 nov. 2012vision-lab.ppt13eye: retina rods retinal + opsin rhodopsin absorbs light across whole visual spectrum cant