chapter 15- vision Flashcards
what is apart of the visual system
eyes
accessory structures
optic nerve
tract
pathways
3 roles for the visual sytem
sight
eye movement
provide info for pastural and limb control
stimulus may be billions of miles away and still be detected
visual stimuli
info regarding light vs dark, movement and color
visual input
pathway for how eyes respond to light
initiate afferent AP-> optic nerves-> optic chiasma-> optic tracts to brain
how many pathways does the visual association area have and what are they
2
ventral & dorsal path
ventral path is where in the brain
temporal visual cortex
dorsal path is where in the brain
parietal virtual cortex
ventral path asks what question
what
dorsal path asks what questions
where
what does the frontal eye field do
interpret location of objects
7 bones surround eyeball and adipose tissues as well (posterior)
eye orbit bones
hair superior to eye orbit. prevent perspiration from running into eyes and irritating, it also shades from direct sunlight
eyebrows
palpebrae; works with eyelashes to protect from foreign objects, lubricates eye, regulates light entering eye, rapid blinking (25x/minute)
eyelids
what muscle opens eye
levator palpebrae
what muscle closes eyelid
orbicularis oculi
space between 2 open eyelids
palpebrae fissue
angle- join medial/lateral margin= blank= modified sebaceous/ sweat glands
canthus
5 layers
skin, areolar CT, skeletal muscles, tarsal plate (dense CT), and papebral conjunctiva
what forms shape of eyelid
tarsal plate
what lines inner eyelid
palpebral conjunctiva
2-3 layers of hair at free edge of eyelid
brush away dust/ foreign objects from eye
eyelashes
sweat glands that lubricates eyelash follicles
ciliary glands
gland inflammation at base of eyelash, usually bacterial infection, pain
stye
tarsal=sebaceous glands at inner margins of eyelids
sebum lubricates tears and restrains tears from flowing over eyelid margi. airtight
meibomian glands
meibomian cyst is
chalazion
chalazion=meibomian=
infection/ blockage of oil gland
is there pain in chalazion
lack pain
treatment for chalazion
warm compresses for 10-15 min/ 3-4 time a day
massage
antibiotics
I&D
steroid injection
opthalmologist
thin, transparent mucous membrane on eyelid, surface of eye, lubricate eye
conjunctiva
cover inner eyelid
palpebral conjunctiva
covers anterior white surface of the eye
bulbar conjuctiva
inflammation of conjuctiva
conjuctivitis
inflammation of conjuctiva=
pinkeye
is pinkeye contagious
yes
causes for conjunctivitis
bacterial
viral
allergic
foreign body or chemical splash
S&S for conjunctivitis
redness, itchy, gritty, discharge with crust, tearing, photophobia
treatment for conjunctivitis
contacts out
compresses
antiinflammatory drops
decongestants
steroids
antivirals
antibiotic eye frops
pataday
artifiical tears
what is innervated by parasympathetic fibers of facial CN VII
lacrimal gland
role in eye protection
lacrimal apparatus
producing tears ->
lacrimal ducts and across anterior eye surface
lacrimal gland goes into
lacrimal sac and through nasolacrimal duct into nasal cavity
what moisturize eye surface, lubricate eyelids, wash away foreign body
lacrimal gland
what is tear composition
predominately H2O, salt, mucus, lysozyme, immunoglobulins
6 extrinsic eye muscles
superior, inferior, medial, lateral rectus
superior, inferior oblique
4 extrinsic eye muscles are controlled by? and what are they
oculomotor CNIII, SR,IR, MR, IO
1 extrinsic eye muscle are controlled by
abducens and trochlear
abducens controls what muscle
LR
trochlear controls what muscle
SO
hollow sphere filled with vitreous humor
eyeball
3 tunics comprise wall:
fibrous tunic
vascular tunic
nervous tunic
outer. sclera and cornea
fibrous
middle. choroid, cillary body and iris
vascular
inner. retina
nervous
white of the eye, posterior 5/6. firm, opaque tissue= dense CT with elasticity
maintains shape of eye, protects internal area, attachment for muscles
sclera
anterior, avascular, transparent structure, stratified squamous epithelium
inner surface is simple squamous. allows light into the eye. focuses
cornea