eye Flashcards
sensory receptord
interface between the nervous system and the internal and external environemnt
general senses
temperature, pain touch, proprioception
special senses
small, taste, balance, hearing, vision
simplest receptors
free nerve ending
retina receptors
specific and only respond to light
receptive fields
receptors far apart and hard to localize stimulus
exteroceptors
information about the external environment
proprioceptors
inormation about body position
interoceptors
inforation about the inside of the body
eye accessory structures
-Palpebrae (eyelids)
-canthus (eyelid at corner)
-palbrae fissure (btwn eyelid)
-lashes
-conjunctiva (epithelial linning eye)
-glands
what triggers blink
root hair plexus
conjunctiva
inside linning eyelid
-produces fluid to keep wet
-ocular conjunctiva= outer
-palbral= inner
glands
protection or lube
glands of zeis
-sebacesous
-eyelashes
tarsals
-keep eyelid from sticking together w lipid rich product
-inner amrgin of eye
lacrimal gland
make tears
lacrimal carnumcle
-thick secretions
-canthus area
cyst
from infection of tarsals gland
sty
infection of any other gland
lacriminal apparatus
-lacrimal gland
-canaliculi
-sac
-nasolacriminal duct
tear flow
-made in lacrimal gland to the ocular surface then the nasolacrimal canal (foramen), enters nasal cavity (runny nose tears)
eye tunics
fibrous tunic, vascular tunic and neural tunic
posterioir cavity
vitreous fluid
posterioir chamber
aqeuous fluid
blind spot
optic disk
-there is no retina there
eye layers
retina to choiroid to sclera
fovea
only cones
vascular tunics (MIDDLE)
choiroid and ciliar body and iris
-blood vessels, intrinsic and lymphatics
-regulate light entering eye
-secrete aqueous fluid
-accomodation
-pigment of eye
fibrous tunic (OUTER LAYER)
cornea and sclera
-attach extraocular muscles
nueral tunic
neural part (inner) and pigmented part (outer)
RETINA
accomodation caused by
cilliary body contraction
-changes focal length to focus on diff diatances
-18 dioptres
anterioir cavity
made of anterioir ad posteiroir chamber
-aqueous
aqueous fluid enters through?
posterioir chamber and flows trough pupil area and enters through anterioir chamber through canal of schlemm and enters venous circulation
canal of schlemm
maintain homeostasis by drainging aqueous fluid to systemic n.s.
build up of fluid in schlemm
glaucoma
detached retina
aquious fluid is not putting enough pressure against the retina
vitrious fluid
support eye shape, lens, retina
limbis stem cells
keep cornea functioning
layers of the cornea
stratified squamous, stroma and posterioir epithelium
lens
epithelium and laminated fibers
-has germinal zone, capsule, fibers
-no organelles bc would block light
-refracts light
-10mm diameter
lens fibers
secondary anucleated
-terminal differentiation
best color vision
fovea centralis
optic nerve
cranial nerve 2
do all fibers cross at the chiasm
no
what regulates light enetering eye globe
iris whihc is in front of the eye
what hold the lens
suspensory ligaments
does the lense grow through life
yes
lens parts
capsule, epithelium and fibers (fibers on anterioir)
does the lense have nerves, bv or c.t
no
crystaline lense capsuel
basement membrane completely surroinding it
-made of collagen 4 whihc is made by the epithelium
lense epithelium
maintain homeostasis of pressure and everything
-nak pump and ions
-progineter for new lens fibers
lens fiber
4-7 micro diameter and 12mm long
-honecomb
-new fibers get added to the outer cortex
-no organelles or nuc (denucleate)
thickest base membrane in the body?
lens capsul
lens if
64 water and 35 protein
get nutrient
diffusion