Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
what is the importance of myelin to the optic nerve?
|
increase resistance, decreases capacitance
-no leaky - thus less energy is required to maintain ionic gradients |
|
|
what is a possible result of loss of myelin on the optic nerve?
|
-loss of myelin would result in changes in resistance and capacitance
-this could result in complete loss of conduction |
|
|
what is uhthoffs phenomenon?
|
transient worsening of MS symptoms
-due to a loss of conduction due to increased temp |
|
|
what is the difference between pallor and excavation?
|
pallor- no loss of tissue; just a color change, tissue looks sick
excavation -- a loss of ganglion cells -- less rim tissue -- quantity |
|
|
what is the most common type of optic neuropathy?
|
glaucoma
|
|
|
true or false
Death of retinal ganglion cells is reversible. |
false
death of retinal ganglion cells irreversible |
|
|
What cells are involved in the vertical retinal pathway? Function?
|
photoreceptors, bipolar cells, ganglion cells
Transmit signal |
|
|
what is the function of the horizontal retinal pathway? and what cells are involved?
|
Modify signal
horizontal cells, amacrine cells |
|
|
which pathway has a larger receptive field, M or P?
|
Magno neurons have large receptive field
|
|
|
what pathways are used for movement contrast?
|
where, when
magno |
|
|
what pathways are important for differentiation of fine detail and color?
|
what, who
parvo |
|
|
which pathway M or P determines the where and what pathways?
|
Magnocellular- Where
Parvocellular- What |
|
|
which type of neuron is excited by specific wavelengths?
|
parvo neurons
|
|
|
what type of neuron response can be (+) or (-) in color coding?
|
parvo neurons
|
|
|
which type of neuron is important for the perception of color?
|
parvo neurons
|
|
|
which type of neuron has the same response regardless of wavelength in color coding?
|
magno neurons
|
|
|
what type of temporal response is seen by parvo neurons?
|
sustained response throughout the duration of the stimulus
temporal low frequencies |
|
|
which type of neurons is responsive to low temporal frequencies?
|
parvo neurons
|
|
|
what type of neuron has a transient response to stimulus?
|
mango cells
-AP is generated right after its turned on or off |
|
|
which type of neuron has a faster transmission speed? why?
|
magno
-has a larger axon diameter |
|
|
which type of neuron has a slower transmission speed?
|
parvo
|
|
|
which type of neuron is more sensitive to low spatial frequencies?
|
magno neurons
|
|
|
what kind of spatial frequency are parvo neurons sensitive to?
|
high spacial frequencies
|
|
|
what are the parts of the retinogeniculate pathway?
|
optic nerve-- optic chiasm-- optic tract-- lateral geniculate nucleus
|
|
|
which ganglion cell is more prevalent, P or M?
|
Parvo
|
|
|
Damage to layers 3-6 would result in?
|
-reduced color vision
-poorer VA |
|
|
What would be expected of a patient who damages layers 1-2 of their LGN?
|
-greater difficulty in detecting large objects
-poor detection for high frequency flicker |
|
|
which type of neuron is not useful in detecting color
|
magno
|
|
|
Which neuron is better at detecting contrast?
|
Magno
|
|
|
Which layers of the LGN are contralateral and which are ipsilateral?
|
1-6
CIICIC |
