The Eye Flashcards
1.2
which part of brain is dedicated to vision?
occipital lobe
schlera
thick structural layer which covers the exposed portion of the eye
white of the eye
What are two blood vessels going into the eye?
choroidal & retinal vessel
retina
contains photoreceptors that turn the light into electrical signals
cornea
A clear window which gathers and focuses the incoming light onto the eye
iris
colored part of the eye
anterior chamber
lies in front of the iris
Posterior chamber
Lies between the iris and the lens
dilator pupillae
muscle of Iris
makes pupil bigger after receiving signal from ‘fight or flight’ system
Constrictor pupilae
constricts pupil after receiving signal from ‘rest and digest’ system
Aqueous humor
fluid made by ciliary body
Fills the front part of the eye; drains out from a channel (canal of schlemm)
ciliary body
A ring of tissue behind the iris
Lens
controls how light enters the eye (bends or refracted
Accomodation
Helps eye focus on objects on different distances
Contracts muscle to constrict the pupil during ‘rest & digest’; pulls suspensory ligaments
Ciliary muscle
under parasympathetic control; component of ciliary body
Vitreous
a clear gel that helps keep retina in place
Duplexity/duplicity theory of vision
states that retina contains two kinds of photoreceptors
those specialized for light and dark
those specialized for color detection
cones
what are the forms of cones? how many?
name them
for color and fine details
Most effective in bright light
Comes in three forms: short (blue), medium (green), long (red)
Rods
More functional and sense light and dark
Low sensitivity to details; No color vision
Rhodopsin
the single pigment of rods
Fovea
center point of macula (center of retina) that contains only cones
bipolar cells
Rods and cones connect to these cells.
They help to highlight differences between adjacent rods or cones
ganglion cells
Bipolar cells connect to ganglion cells.
These cells group together to form the optic nerve, which sends visual information to your brain
where are horizontal cells and bipolar cells located ?
they are located in front of the rods and cones, closer to the front of the eye.
why does color vision can see more detail than black and white vision ?
fewer cones connect to a single ganglion cell than rods
Parallel Processing
being able to easily recognize and understand what is happening because of the color, shape, and motion
spatial resolution
Very fine details of an object
parvocellular cells
Cells that detect shape; that have a very high color spatial resolution
temporal resolution
refers to how quickly something can change or happen over time.
Magnocellular cells
detect motion
have low temporal resolution
Visual Cortex
Region of the cerebral cortex located in the occupital lobe of the brain
Processes visual information received from the eyes
optic chiasm
Forest event as the signal travels through the optic nerves towards the brain
Spot in the brain where optic nerves cross each other
lateral geniculate nucleus
Structure in the thalamus
role in visual pathway
Broadcasts information from the retina to the visual cortex
Sympathetic nervous system
dial its pupil for fight or flight
allowing more light
Parasympathetic nervous system
Constricts pupil to restrict light
Eustachian tube
joins ear and nose
