Busy. Please wait.
Log in with Clever

show password
Forgot Password?

Don't have an account?  Sign up 
Sign up using Clever

Username is available taken
show password

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't Know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

BIO 435


What does the eye detect? light
What factors must the eye encode of light? 1. intensity 2. wavelength (visible light has a wavelength from 400nM to 700 nM) 3. location
What part of the eye is specialized to focus light? photoreceptor cells
What is the purpose of the cornea The cornea is specialized to refract light waves to focus light on the retina
Where does information leave the eye? optic nerve
What is the beginning of the optic nerve? CN II
Why does the lens "accommodateā€¯? The lens accommodates to help with refraction; accommodation allows for focusing on close objects
What does the lens do when it is unaccommodated? The lens is smaller
What does the lens do when it is accommodated? Widens; the lens also widens when an object is close
What does the accommodation reflex require? The accommodation reflex requires an intact midbrain and oculomotor nerve (CN III)
As you age, what ability do you lose? the ability to accommodate your lens and help with light refraction.
What do photoreceptor cells in rods do? detect visible light
What do photoreceptor cells in cones do? detect specific wavelengths of visible light
What NTs do photoreceptor cells release? Glutamate
What kind of action potentials occur in photoreceptor cells? graded potentials
Where are photoreceptor cells located? In the back of the retina
Where are there lots of cones in the eye? macula/fovea
Where is the area with the highest visual acuity (the ability to distinguish two points near each other)? macula/fovea
What are cones responsible for? color and form, fine detail, daytime vision
What are rods responsible for? movement and low-light situations (night vision)
Where are there no cells in the retina? In the blind spot
Where does transduction of light occur? In the outer segments
What do photoreceptor cells do when exposed to light? hyperpolarize
What happens when photoreceptor cells are in darkness? lots of Na+ channels open causing cells to depolarize and reach -30mV and some Glu is released
What happens when photoreceptor cells are in the light? Na+ channels close, cell hyperpolarizes, and the release of Glu is stopped
What is the rhodopsin GPCR made of? opsin and retinal
What happens when light hits retinal? It is activated
What is retinal converted to when it is deactivated? 11-cis
How do photoreceptor cells respond to light? Proportionally, cells hyperpolarize the most in bright light and the least in dim light
Why does each cone respond to a different wavelength? Because each cone has a different receptor
What is the wavelength that each cone responds to? blue
How would you describe someone's visual field? part of space that you can see in one position without moving your head
What is the receptive field of photoreceptor cells? The spot on the retina where the light influences the photoreceptor cell
What do bipolar cells receive input from? photoreceptor cells
What do ganglion cells receive input from? Bipolar cells
Where do ganglion cells project to? the brain
What do horizontal cells allow for? Horizontal cells allow for communication between photoreceptor cells
What do amacrine cells do? Amacrine cells modulate input to ganglion cells
What results in high acuity integration in bipolar neurons? When there is one photoreceptor cell and one bipolar cell in the fovea
What results in low acuity integration in bipolar neurons? When there are many photoreceptor cells and one bipolar cell outside of the fovea
What must be absent for glutamate to be released in bipolar cells? No action potentials can be occurring
Describe what occurs in on-center bipolar cells - Metabotropic receptors -inhibited by glutamate -stay depolarized when the photoreceptor cells is in the light
Describe what occurs in off-center bipolar cells - Ionotropic receptors -depolarized by glutamate -only release NTs when photoreceptor cell is in the dark
Describe the receptive field of bipolar cells -larger receptive fields -there are 1 to several direct synapses (in the center) -lots of indirect synapses via horizontal cells (in the surrounding) -receptive fields of neighboring bipolar cells overlap
What are horizontal cells activated by and what do they do? Horizontal cells are activated by glutamate and inhibit neighboring photoreceptor cells by releasing GABA
When are on-center bipolar cells maximally depolarized? When there is light in the center and the surrounding is dark
When are off-center bipolar cells maximally depolarized? When there is darkness in the center and light in the surrounding
What type of glutamate receptors do ganglion cells have? Ionotropic
What type of cells do ganglion cells do the exact same thing as? Bipolar cells; they are center-surrounded
Why are ganglion cells able to have action potentials unlike bipolar cells? They are really long
Describe the occurrence of action potentials in off-center ganglion cells - When it is dark inside the receptive field = there are more action potentials -When it is all light/all dark in receptive field = the baseline response is present
Describe the occurrence of action potentials in on-center cells - light in the center of the receptive field= increase in the number of action potentials -all light/all dark in all receptive field= baseline response rate
How are ganglion cells differentiated? By size
Describe M-type ganglion cells LARGE; respond most to change; receive most input from rods and recognizes movement
Why do M-type cells have rapidly changing response rates? Because M-type ganglion cells recognize movement
Describe P-type ganglion cells SMALL; respond to less stimulus than M-type; receive input from cones and recognize color more
Where do ganglion cell axons leave the eye? Through the optic nerve (CN II)
Where do most (90%) of retinofugal projections from ganglion cell axons go? the lateral geniculate nucleus of the thalamus
What other places in the brain do retinofugal projections from the ganglion cell axons and optic nerve go? superior colliculus, hypothalamus
Where do axons in the nasal half of each eye decussate at? The optic chiasm
Does information from the right visual field (from either eye) go to the right side of the brain on the left side of the brain? left
What type of cells are the receptive fields of LGN cells most identical to? Ganglion cells
What might the lateral geniculate nucleus do? focus attention
Where does the LGN project to? primary visual cortex (V1); responsible for optic radiation
What are the spatial maps of visual field called? retinotopy
From where do most of V1 process information? Fovea
Where does the input from layers in the V1 go? 1. M cells input in LGN go to 4ca (4C alpha) 2. P cells input in LGN go to 4CB (4C beta)
What are the two layers in the LGN? M-type layer P-type layer
From which layers in the primary visual cortex is output mostly from? Layers 3 - goes to other cortical layers layers 5 and 6 - subcortical
In which layer of v1 is information from each eye still separate? Layer 4
Where do most neurons in layer 4c project to? Layer 3 (this is a connection within the striate cortex)
In which layer are there binocular cells and in which layers cells is input from both eyes combined? Layer 3
What are some cells outside of layer 4c described as? These cells have receptive fields that use bars of lights as best stimulus Ganglion cells with orientation-specific receptive fields
What most likely underlies orientation-specific receptive fields? spatial summation
Where does information from the V1 go to? -the visual cortex (V2) -dorsal pathway (for localization) -ventral pathway (for identification)
What type of neurons have large receptive fields that require specific types of motion? Dorsal stream neurons
What disease results from damage to the dorsal stream neurons? akinetopsia
What type of neurons have large receptive fields that require very specific objects? ventral stream neurons
Created by: keiannaowens
Popular Neuroscience sets




Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
restart all cards