1000ft view vision Flashcards
what are the layers of the eye
fibrous tunic
vascular tunic
sensory/neural tunic
what is part of the fibrous tunic
cornea
sclera
what is part of the vascular tunic
iris
choroid
ciliary body
what is part of the sensory/neural tunic
retina
vitreous humor
what is the sclera
white aspect of the eye - surrounds the eye
dense CT which assists with protection/shape
attaches to the cornea at the limbus
what is the point of attachment for eye muscles
sclera
what prevents light waves from scattering by absorbing them
sclera
What is the limbus
the area where the sclera attaches to the cornea
which cranial nerves affect the eyes
Cranial nerve II (vision)
CN IV - superior oblique
CN VI - lateral rectus
CN III - all other muscles
What creates the pupil
iris
what portion of the eye is vascular
iris
what nerve innervates the pupil
CN III
What is Miosis
sphincter pupillae helps to constrict
what is mydriasis
dilator pupillae helps to dilate
what is the job of the choroid
helps deliver nutrients to the photoreceptor neurons and assists with absorption of light by preventing reflection or scattering
where is the choroid located
vascular layer that wraps from the ciliary body around the posterior aspect of the eye
What is the ciliary body
helps to pull the lens and allow for accommodation - attaches to the lens
secretes aqueous humour which fills the anterior chamber
what is the lens of the eye
transparent structure that refracts light
can be pulled to alter the shape and focus light allowing for accommodation via the ciliary body
made up of capsule, epithelium and fibers
what maintains the intracocular pressure
aqueous humour
what is vitreous humour
thick, jelly like fluid in the posterior aspect of the eye
keeps intraocular pressure
born with set amount
What is the canal of schlemm
where aqueous humour drains out of the eye
where are tears made
lacrimal gland
What is the meibomian gland
oil glands along edge of the eyelid
secretes oil which keeps tears from evaporating too quickly
what is the Zeis gland
sebaceous gland
what is the moll gland
apocrine gland
where are the moll and Zeis gland located
on the eyelid
what is the area with the highest visual acuity
macula lutea
what does the fovea centralis contain
only cones
what are the photoreceptors
rods and cones
what are the cones
color and visual acuity under well lit conditions (photopic vision)
contains photopsin which helps pick up the different colors of the visible light spectrum (ones designated to red, green, blue)
what are the rods
balck/white/grey vision in poorly lit environments. Night vision.
contrains Rhodopsin
what are bipolar cells
in-between the photoceceptors and ganglion cells
what are ganglion cells
long axons form together to create CN II (optic nerve)
what is the process of vision
photon hits photoreceptor
chemical changes within the pigmented proteins (rhodopsin and photopsin)
this will cause cellular change allowing for ion exchange
hyperpolarized the cell
releases glutamate
stimulates bipolar cells - releases more glutamate
action potential to stimulate ganglion cells
area stimulated will be on the nasal hemi retina or temporal hemi retina
receives input from opposite side
stimulation travels along ipsilateral side of the optic nerve
What is OD
Right eye
What is OS
left eye
what is IOP
intraocular pressure 11-21
what is hemianopsia
loss of one half of vertical visual fields
what is anisocoriaa
asymmetric pupil size
