eye/ear (neuro system) Flashcards
what is the external eye protected by
skull, eyebrow, eyelash, conjuctiva, exocrine, lacrinal glands
ciliary muscle
help change shape of lens
-smooth muscle
-ligament
-found in choroid layer
ciliary muscle contracting
suspense ligament relax’s, thick lens
for close vision
ciliary muscle relaxing
suspense ligament tightens, thin lens
for distant vision
aquous humor
fills cavity between cornea and lens
-supplies nutrients to cornea
-anterior/front
-refracts light
-sclera layer
pupil
only opening for light to enter the eye
-not a structure
-choroid layer
cornea
transperant for light to enter
-curved (helps light reach)
-focusing light
-clear image
-sclera layer
iris
change pupil diamter
-colored part of the eye
-regulates light entering
-choroid layer
ligaments
connect muscles to other things
lens
focus light on retina
-inverted
-choroid layer
vitrious humor
supporting chamber
-back chamber
-jelly like
-focus’s light onto retina
-choroid layer
folrea centralisis
high concentration of cones
-for detail, like reading
-on retina
optic nerve
sends an electric signal to occiputal lobe
-pathway
blind spot
point where optic nerves attached
-not a structure
-no rod or cones
sclera
tough elastic outer layer
-protection/shape
choroid
dark middle layer
-vascularized, supplies the eye with nutrients/blood
-prevents interal light reflection
retina
light sensitive cells
-innermost layer
-electrical impulse to occipal lobe
-pigment layer
-rod and cones
extrensic muscles
move the eyeball
-up down side to side diagnol
-sclera layer
pigment layer
layer with light sensitive ce4lls
rods and cones
interpret light signals
-a light stimulus turns into action potential that goes to occiptical lobe
rods
respond to all light
-black and white vision
cones
more sensitive to RGB
-less cones than rods
-detail
-color vision
bipolar cells
synapse with rod/cones to rekay optic nerve
-rods contain many
-cones contain a 1:1 ratio
ganglion cells
axons from optic nerve to brain
right to left magnified eye layers
-sclera
-choroid
-rod/cones
-bipolar cells
-ganglion
-terminal to occipital lobe
myopia
near sightedness
-eyeball too long, ray focusing infront of retina
hyperopia
far sightedness
-eyeball too short, ray focusing behind the retina
fixes for myopia and hyperopia
-need concave
-need convex
astigmatism
lens and cornea irregularily shaped, light bounces in different direction adding extra “lines”
focusing on near objects
ciliary muscles contract
-ligaments are loose
-lens round
focusing far objects
-ligaments tight
-lens flatten
why would someone need glasses
lens harden over time. no longer bend as well
glaucoma
buildup of aqueous humor/inner pressure
-retinal bloodvessels collapse
-lead to blindness
catracts
lens is opaque, and less light can pass through
rhodopsin
a pigment found in rod cells that absorbes light
contains
-opsin
-retinene
opsin
protein
retinene
derivation of vitamin A
-pigment part
what happens when rhodopsin absorbs light
retinene changes form, breaking chemical bond w opsin
-H+ ions release
-depolarize bipolar cells
-AP
rhodopsin resynthesizes due to
absence of light
fovea centralis
high concentration of cones
three types of cones
-red
-blue
-green
different combinations create all colors
white and black stimulation/color
white : all equally firing
black : nothing is firing
color blindness
one or more cone types if defective
ear mechanoreceptors
-sound waves (pressure)
-orientation (static equilibrium)
-motion (dynamic equilibrium)
outer ear
cartiledge portion
pinna
ear flap, ear lobe
-collects and directs sound waves
auditory canal
carries sound to the eardrum
-protects ear
ceruminous glands
specialized sweat glands that produce earwax
-first line protection
middle ear
air filled space
-begins at eardrum
tympanic membrane
eardrum
-vibrates with sound
eustachian tube
connects middle of the ear with nose and mouth
-air pressure
ossicles
amplify vibrations of tympanic membrane
-transfer to oval window
-hammer (malleus)
-anvil (incus)
-stirrup (strapes)
inner ear
fluid filled cochlea
cochlea
snail shaped tube/hollow
-oval window
ovil window
attached to stapes, recieves sound
-vibrations cause waves to pass along cochlear fluid
organ of corti
after passing through ovil window
-ears primary sound receptor
-specialized hair cells
