senses----eyes

what are the acvessory organs for sense of sight

eyelids, eyelahses, lacrimal apparatus, extrinsic eye muscles

4 layers of the eyelids are

skin, muscle, connective tissue, conjunctiva

what muscle closes eyelid

orbicularis oculi

what muscle opens the eyelid

levaor palpebrae superioris

tarsal glands function

secrete oil onto eyelashes

conjunctiva function

mucus membrane that lines the eyelid and covers protion of eyeball

what secretes your tears

lacrimal gland

canaliculi function

two ducts that collect tears

lacrimal sac function

collects tears from canliculi and lies in groove of lacrimal bone

nasolacrimal duct function

empties tears into nasal cavity

what is the name of the antibaerical componenet of tears

lysozyme

superior rectus function

rotates eye up/medial

inferior rectus function

rotates eye down immedially

medial rectus function

rotates eye medially

lateral rectus

roates eye lateraly

superior oblique

rotates eye down laterally

infeior oblique

roate eye up and laterally

what are the three layers of wall of eye (from outer to inner)

fibrous tunic, vascular tunic, nervous tunic

outer fibrous tunic contains what two things

cornea and sclera

cornea function

help focus light rays that come into eye. transmit and refract that light

sclera function

protects the eye and attacthes muscles.

what make up the middle vascular tunic of eye

choroid coat, ciliary body, iris

choroid coat functioj

provides blood supply, contains melanocytes

ciliary body function

forms rings to hold lens which changes lends shape for focusing

iris function

in front of lens, pigemented, and controls amount of light entering eye

lens

transpareant and elastic. held in place by suspensory ligaments of icliary body. job is to help focus light rays. it changes shape

what is accomodation of lens

change in shape of lens to view close objects

when focusing on closer object what does lens do

lens thickens and becomes more convex

when focusing on farther object what does lens do

thins and becomes flatter

ciliary muscle function

relaxes the suspensory ligaments during accomodation

what controls amount light thats entering eye

iris

iris consists of

connective tissue and smooth muscle

when does pupil dilatw

in dim light which stimulates radial muscles to make pupil dilate

what does bright light do to pupil

stimulates circular muscles making the pupil constrict

where is retina (which tunic)

inner tunic

layters of retina

macula lutea, fovea centralis, optic disc, vitreous humor

macula lutea

yellow spot in retina

fovea centralis

center of macula lutea, produces sharpest visiono

optic disc

blind spot, contains no photoreceptors. found where nerve fibers from retina leave the eye to become optic nerve

vitreous humor

thick gel that holds retina flat against choroid coat and help maintain eye shape

pphobia centraltis only contains

cones

visual pathway

ganglion cells of retina, optic nerve, optic chiasma, optic tract, thalamus, optic radiation, visual cortex in occipitial lobeof cerebrum