Term
| T/F Vision is the dominant sense to adapt to change in the environment. |
|
Definition
|
|
Term
| where does all sensory input go to? |
|
Definition
|
|
Term
| what are the levels of processing for the visual sense? |
|
Definition
eyes->
thalamus->
primary visual cortex |
|
|
Term
| what is phototransduction? |
|
Definition
| convert light energy into action potentials |
|
|
Term
| what is parallel processing? |
|
Definition
| information is processed at multiple locations at the same time |
|
|
Term
| give an example of parallel processing. |
|
Definition
the brain divides what it sees into color, motion, shape, and depth.
These components are individually analyzed and then compared to stored memories |
|
|
Term
| what is hierarchal processing? |
|
Definition
| information is processed first at one level then output to another higher level |
|
|
Term
| give an example of hierarchal processing. |
|
Definition
| objects can be viewed as a collection of lines, then shapes, then into objects |
|
|
Term
| explain conscious visual perception. |
|
Definition
| active focus on the visual stimuli to interpret what was seen |
|
|
Term
| where is visual information from the retina relayed to? |
|
Definition
| the lateral geniculate nucleus of the thalamus to the primary visual cortex |
|
|
Term
| where is the lateral geniculate nucleus located? |
|
Definition
|
|
Term
| what is the central visual system (CVS)? |
|
Definition
| a pathway in which information from out visual field is processed |
|
|
Term
| what is a binocular visual field? |
|
Definition
| the sum of both eyes is interpreted as one picture |
|
|
Term
| T/F visual stimuli from each eye only projects to one side of the brain. |
|
Definition
false
each eye projects to each side of the brain |
|
|
Term
| what are the three components of the retina? |
|
Definition
retina
interneurons
ganglion cell |
|
|
Term
| name the ten layers of the retina. |
|
Definition
1-Pigment Epithelium
2-Rod and Cone Layer
3-External Membrane
4-Outer Nuclear Layer
5-Outer Plexiform Layer
6-Inner Nuclear Layer
7-Inner Plexiform Layer
8-Ganglion Cell Layer
9-Optic Nerve Fiber Layer
10-Internal Limiting Membrane |
|
|
Term
| what are the three types of interneuron? |
|
Definition
bipolar cells
amacrine cells
horizontal cells |
|
|
Term
| what is the function of the interneurons? |
|
Definition
| further sort visual information |
|
|
Term
| what is the pigment epithelium? |
|
Definition
deepest layer
absorbs excess light |
|
|
Term
| what is the rod and cone layer? |
|
Definition
|
|
Term
| what is the external membrane? |
|
Definition
| intercellular junction binding Mueller cells |
|
|
Term
| what is the outer nuclear layer? |
|
Definition
| cell bodies of rods and cones |
|
|
Term
| what is the outer plexiform layer? |
|
Definition
| synaptic area with terminals of rods and cones and horizontal and bipolar cells |
|
|
Term
| what is the inner nuclear layer? |
|
Definition
| cell bodies of interneurons |
|
|
Term
| what is the inner plexiform layer? |
|
Definition
| synaptic area of terminals of interneurons and ganglion cells |
|
|
Term
| what is the ganglion cell layer? |
|
Definition
| cell bodies of ganglion cells |
|
|
Term
| what is the optic nerve fiber layer? |
|
Definition
| axons of ganglion cells form thick bundles of the optic nerve which terminates in the lateral geniculate nucleus of the thalamus |
|
|
Term
| what is the internal limiting membrane? |
|
Definition
| membrane made of basal lamina between vitreous body and Mueller cells |
|
|
Term
| what is a general description of the retina? |
|
Definition
| thin layer of cells at the back of the eyeball which converts light into nervous signals |
|
|
Term
| T/F the retina detects light but also plays an important role in visual perception. |
|
Definition
|
|
Term
explain the rods.
how many?
what do they detect?
where are they located? |
|
Definition
100-120 million
stimulated by low levels of light
located at the periphery |
|
|
Term
explain the cones.
how many?
what do they detect?
where are they located? |
|
Definition
6-7 million
stimulated by high intensity light and mediate sharp vision and color
centrally located |
|
|
Term
| T/F cones detect shades and dark. |
|
Definition
|
|
Term
| T/F cones detect light and detail. |
|
Definition
|
|
Term
| T/F interpretation of visual stimulus does not require conscious thought. |
|
Definition
|
|
Term
what is the outer segment of rods and cones?
what is it? |
|
Definition
dendritic end
photosensitive-modified cilium |
|
|
Term
| the inner segment of the rods and cones house what? |
|
Definition
|
|
Term
| explain the discs in the rods and cones. |
|
Definition
rods: discs form within the cytoplasm
cones: discs are infoldings of the outer segment |
|
|
Term
| what is a general description of the retina? |
|
Definition
| thin layer of cells at the back of the eyeball which converts light into nervous signals |
|
|
Term
| T/F the retina detects light but also plays an important role in visual perception. |
|
Definition
|
|
Term
explain the rods.
how many?
what do they detect?
where are they located? |
|
Definition
100-120 million
stimulated by low levels of light
located at the periphery |
|
|
Term
explain the cones.
how many?
what do they detect?
where are they located? |
|
Definition
6-7 million
stimulated by high intensity light and mediate sharp vision and color
centrally located |
|
|
Term
| T/F cones detect shades and dark. |
|
Definition
|
|
Term
| T/F cones detect light and detail. |
|
Definition
|
|
Term
| T/F interpretation of visual stimulus does not require conscious thought. |
|
Definition
|
|
Term
what is the outer segment of rods and cones?
what is it? |
|
Definition
dendritic end
photosensitive-modified cilium |
|
|
Term
| the inner segment of the rods and cones house what? |
|
Definition
|
|
Term
| explain the discs in the rods and cones. |
|
Definition
rods: discs form within the cytoplasm
cones: discs are infoldings of the outer segment |
|
|
Term
| what is the pigment of rods? |
|
Definition
|
|
Term
| what is the pigment of cones? |
|
Definition
|
|
Term
| what triggers the rods and cones? |
|
Definition
|
|
Term
| where does phototransduction being and end? |
|
Definition
begins: rhodopsin in the disk membrane
ends: in plasma membrane hyperpolarization |
|
|
Term
| what happens when light strikes a photoreceptor? |
|
Definition
| it it initiates a process that reduces the release of glutamate |
|
|
Term
| what does glutamate affect in visual processing in the retina? |
|
Definition
| the activity of bipolar and horizontal cells |
|
|
Term
| what do bipolar cells synapse with in visual processing in the retina? |
|
Definition
| amacrine and retinal ganglion cells |
|
|
Term
| the transduction of visual information from the eye to the brain uses what types of cells? |
|
Definition
| bipolar and ganglion cells |
|
|
Term
| what is the role of horizontal cells in the visual processing in the retina? |
|
Definition
| modulate the synaptic activity of receptor cells |
|
|
Term
| what is the role of amacrine cells in the visual processing in the retina? |
|
Definition
| modulate synaptic activity of the retinal bipolar and ganglion cells |
|
|
Term
| what happens when cGMP concentration decreases? |
|
Definition
|
|
Term
| what happens to cGMP concentrations in dark conditions? |
|
Definition
|
|
Term
| what happens to cGMP concentrations in light conditions? |
|
Definition
|
|
Term
| what receptors are embedded in the disc membrane? |
|
Definition
| G-protein couples receptors |
|
|
Term
| what is important to note about G-protein coupled receptors? |
|
Definition
| they have second messengers |
|
|
Term
| the combination of rhodopsin and vitamin a make what? |
|
Definition
|
|
Term
| what are the steps of phototransduction? |
|
Definition
1-light is absorbed by rhodopsin->makes metarhdopsin->activates transducin
2-transducin binds to GTP
3-the alpha subunit-GTP complex activates phosphodiesterase
4-phosphodiesterase breaks down cGMP to 5'-GMP (decreases cGMP concentration)
5-sodium channels close causing hyperpolarization
6-hyperpolarization causes VGCC to close reducing glutamate concentration
7-decreased glutamate causes depolarization of ON center bipolar cells and hyper polarization of OFF center bipolar cells |
|
|
Term
|
Definition
| light is absorbed by rhodopsin, with combination of vitamin a metarhodopsin is made and then transducin |
|
|
Term
| how is metarhodopsin 2 made? |
|
Definition
|
|
Term
| what converts cGMP to 5'-GMP? |
|
Definition
|
|
Term
| what gates close when the concentration cGMP decreases? |
|
Definition
|
|
Term
| what happens when metarhodopsin 2 hits the GProtein? |
|
Definition
| the alpha subunit triggers phosphodiesterase |
|
|
Term
| what is the key molecule of phototransduction? |
|
Definition
|
|
Term
| what depolarizes OFF bipolar cells? |
|
Definition
|
|
Term
| what hyper polarizes ON cells? |
|
Definition
|
|
Term
|
Definition
| detect dark objects in a lighter background |
|
|
Term
|
Definition
| detect objects in a dark background |
|
|
Term
| what are the two modes of action of glutamate? |
|
Definition
| depolarize OFF bipolar cells and hyper polarizes ON bipolar cells |
|
|
Term
| depolarization of horizontal cells causes the release of what? |
|
Definition
|
|
Term
what cells depolarize by the release of glutamate in no light conditions?
what happens in light conditions? |
|
Definition
horizontal cells
horizontal cells are not depolarized |
|
|
Term
| explain the statement: Bipolar cells have concentric receptive fields" |
|
Definition
| Light directed on a photoreceptor that synapse with a bipolar cell produces a center response. Whereas light directed on immediately surrounding receptors produce the opposite response. |
|
|
Term
| cone-bipolar cell is color sensitive/insensitive. |
|
Definition
|
|
Term
| rod-bipolar cell is color sensitive/insensitive. |
|
Definition
|
|
Term
| OFF triggers depolarization/hyperpolarization. |
|
Definition
|
|
Term
| ON triggers depolarization/hyperpolarization. |
|
Definition
|
|
Term
| T/F bipolar cells synapse on multiple rods and cones. |
|
Definition
|
|
Term
| explain why ganglion cells are the final output neurons. |
|
Definition
| collect visual information from the interneurons and transmit it to the brain |
|
|
Term
| T/F amacrine cells are the second synaptic retinal layer. |
|
Definition
|
|
Term
which direction do amacrine cells shift information?
how? |
|
Definition
laterally
through extensive dendritic trees |
|
|
Term
| P ganglion cells make synaptic contact with ____bipolar cells. |
|
Definition
|
|
Term
| characterize P ganglion cells. |
|
Definition
color sensitive
small concentric receptive field
produces a slow adaptive response
produces weak responses to stimuli |
|
|
Term
| T/F rods-> interneuron layers-> ganglion cells-> P ganglion cells |
|
Definition
|
|
Term
| M retinal ganglion cells synapse with ____ bipolar cells. |
|
Definition
|
|
Term
| characterize M rential ganglion cells. |
|
Definition
color insensitive
large concentric receptive field
sensitive to small center-surround brightness differences
produces rapid adaptive response
detects motion in the periphery |
|
|
Term
| T/F M retinal ganglion cells are larger than P ganglion cells. |
|
Definition
|
|
Term
| what makes up the optic nerve? |
|
Definition
| retinal ganglion cell axons and support cells |
|
|
Term
| where do most of the axons of the optic nerve terminate? |
|
Definition
| lateral geniculate nucleus |
|
|
Term
| what is the optic chiasm? |
|
Definition
| part of the brain where the optic nerves partially cross over |
|
|
Term
|
Definition
| continuation of the optic nerve from the optic chiasm to the lateral geniculate nucleus |
|
|
Term
|
Definition
| loop into the temporal lobe (memory) to get to the visual cortex |
|
|
Term
| what would happen if there was damage to the temporal lobe, what could happen to vision? |
|
Definition
| possible to lose vision in the part of the eye that deals with that quadrant (superior quadrant) |
|
|
Term
| what is the pathway of optic radiation? |
|
Definition
photoreceptors->
bipolar cells->
ganglion cell bodies->
optic nerve->
quadrants->
cross at chiasm->
LGN->
fan out at Meyer's Loop->
visual cortex |
|
|
Term
| what is the purpose of Meyer's Loop? |
|
Definition
| feed visual information to a memory structure |
|
|
Term
| visual information goes to what memory structures in the brain? |
|
Definition
|
|
Term
| what does the parietal lobe deal with? |
|
Definition
|
|
Term
| what is another name for optic radiation? |
|
Definition
|
|
Term
| explain association cortex. |
|
Definition
3 areas shape visual information
occipital
temporal
parietal |
|
|
Term
| what is the total visual field? |
|
Definition
| entire are that can be seen with both eyes |
|
|
Term
| T/F visual information is shared across both hemispheres |
|
Definition
|
|
Term
where does the retina project mainly?
what two other structures? |
|
Definition
lateral geniculate nucleus
superior colliculus
hypothalamus
pretectum |
|
|
Term
| where does the LGN relay information? |
|
Definition
|
|
Term
| what is the superior colliculus in charge of? |
|
Definition
|
|
Term
| what does the pretectum control? |
|
Definition
|
|
Term
| T/F 10-20% of visual information goes to the LGN. |
|
Definition
false
80-90% to the LGN
10-20% to the SC |
|
|
Term
| explain the pathway of optic projection. |
|
Definition
Retina->
LGN->
VI+ (PVC)->
the projects forward |
|
|
Term
| the multiple sites of visual processing is an example of |
|
Definition
|
|
Term
| the thalamus is synonymous to |
|
Definition
|
|
Term
| the thalamus is responsible for what? |
|
Definition
| initial processing of all sensory information except olfaction |
|
|
Term
| what is the lateral part of the thalamus responsible for? |
|
Definition
| integration of sensory information and sends nerve impulses to the parietal, temporal and occipital lobes for further processing |
|
|
Term
| how many layers are there in the LGN? why? |
|
Definition
6
because there are 6 layers of the visual cortex |
|
|
Term
|
Definition
| primary relay center for visual information from the retina |
|
|
Term
| where does the LGN come into play in optic radiation? |
|
Definition
rods and cones project to the->
LGN projects to the cortex |
|
|
Term
| if visual information comes in at the right side of the eye what hemisphere does it project to? |
|
Definition
|
|
Term
| what are the cell types of the LGN? |
|
Definition
|
|
Term
| what is the source of information for M cells? |
|
Definition
|
|
Term
| what is the source of information for P cells? |
|
Definition
|
|
Term
| what is the point of splitting information from each side of the brain? |
|
Definition
| the angle at which light enters each eye is different at different angles |
|
|
Term
|
Definition
| in the midbrain posterior to the thalamus |
|
|
Term
| T/F the SC is part of the thalamus. |
|
Definition
|
|
Term
| where does sensory input to the SC come from? |
|
Definition
vestibular apparatus
retina
PVC |
|
|
Term
| what is the tectospinal tract? |
|
Definition
| projection to the level of the spinal cord |
|
|
Term
| no matter the source of input to the SC what track is taken? |
|
Definition
SC->
brain stem->
AMN->
muscles of the head and neck |
|
|
Term
| give an example of the SC and reflexive control of the head and neck. |
|
Definition
flash of light to your left causes you to turn your head to the left
1)retina projects to the superficial layers of the right SC
2)superficial layers to the intermediate and deep layers
3)long crossed tectospinal axons to the left side of the cervical spinal cord
4)spinal cord neurons on the left side innervate head and neck muscles
5)turn your head to the left |
|
|
Term
| T/F specific areas of the SC handle specific information |
|
Definition
|
|
Term
| what does the topographical map the SC creates represent? |
|
Definition
represents visual space around us with input from auditory and somatosensory sources
creating spacial awareness |
|
|
Term
|
Definition
| the eyes are directed toward a motionless object, with eye movements to compensate for movements of the head |
|
|
Term
|
Definition
| the eyes move steadily to track a moving object |
|
|
Term
|
Definition
| the eyes move rapidly from one location to another (jumps) |
|
|
Term
|
Definition
| the eyes move simultaneously in opposite directions to obtain or maintain single binocular vision |
|
|
Term
| T/F there are six layers in the PVC just like the LGN. |
|
Definition
|
|
Term
| what are the layers that have reasonable information. |
|
Definition
|
|
Term
| V1 receives input from where? |
|
Definition
|
|
Term
| V1 is also known as what? |
|
Definition
|
|
Term
| V1 transmits information on what two pathways? |
|
Definition
ventral stream
dorsal stream |
|
|
Term
| M type cells project to what lobes |
|
Definition
medial temporal lobe
then to parietal lobe |
|
|
Term
| the P cells project where? |
|
Definition
| to V4 then into the temporal lobe |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| what type of cells detect movement? |
|
Definition
|
|
Term
| what type of cells detect shapes? |
|
Definition
|
|
Term
| the ventral stream is associated with what? |
|
Definition
form recognition and object representation and color
storage of long term memory |
|
|
Term
| the ventral stream is associated with what types of cells? |
|
Definition
|
|
Term
| what is another name for the ventral stream? |
|
Definition
|
|
Term
| the dorsal stream is associated with what? |
|
Definition
motion
representation of objects locations
control of eyes and arms |
|
|
Term
| the dorsal stream is associated with what types of cells? |
|
Definition
|
|
Term
| what is another name for the dorsal stream? |
|
Definition
|
|
Term
| what did a study of reaction time in baseball players find? |
|
Definition
| better hitters had better reaction times |
|
|
Term
| what does time to contact equal? |
|
Definition
| size of the retinal image divided by the rate of change in size of the image |
|
|
Term
| what did whiting find in his vision and catching study? |
|
Definition
| the longer people had to look at the ball before the light turned off the more catches were made |
|
|
Term
| what are the three ways the PVC elaborates the elemental information from the cells? |
|
Definition
1)each part of the visual field is decomposed into short line segments through orientation columns
2)color processing occurs in cells that lack orientation selectivity in regions called blobs
3)the input from the two eyes is combined through the ocular dominance columns, necessary for depth perception |
|
|
Term
| the ganglion cells projects to the LGN in a way that creates what? |
|
Definition
| a complete retinotopic map of the visual field for each eye |
|
|
Term
| T/F the M and P cells of the retina project to the same areas of the LGN |
|
Definition
|
|
Term
| where does each geniculate axon terminate mainly? |
|
Definition
|
|
Term
| neurons with similar response properties in different vertically oriented systems are linked by what connections? |
|
Definition
|
|
Term
| what does the SC control? |
|
Definition
|
|
Term
| T/F the SC is part of the thalamus. |
|
Definition
|
|
Term
| where do most of the projects to the SC come from? |
|
Definition
|
|
Term
where does the SC project information to?
and further? |
|
Definition
the brain stem
to the cervical spinal cord to innervate AMN to innervate muscles in the head and neck |
|
|
Term
| the SC receives input from the retina but also where else? |
|
Definition
|
|
Term
Explain the notion that the SC creates a topographic map.
what does this give us? |
|
Definition
receives stimulus from rod and cones to create a 2D map of the visual field, which can be divided into upper and lover quadrants.
subconscious recognition in space |
|
|
Term
| some retinal projects bypass the LGN and go where? |
|
Definition
|
|
Term
| what level of the visual cortex does most visual input go to? |
|
Definition
|
|
Term
| explain the pathway to the visual cortex. |
|
Definition
light->
retina->
6 layers of the LGN->
6 layers of the visual cortex |
|
|
Term
| what direction does the levels of the visual cortex share information? |
|
Definition
|
|
