Chapter 9 Midterm 2 Flashcards
Each sensory systems receptors are designed to respond to what?
A narrow band of energy, for each sense it’s:
Vision: Light energy produces chemical energy.
Auditory and Balance: Pressure produces mechanical energy.
Somatosensory: Mechanical energy
Taste and olfaction: Chemical molecules
Stimuli is being brought in through what? What do they produce?
senses and they produce action potentials
Perception of a sensory system is though to be what?
a function of the unique neural wiring in each sensory system
Perceptual experiences are _____ interpretations of the world?
Neural
When female is giving birth what can they do to stop pain?
give tap in spinal cord that shuts down pain signals reducing pain
Visual migraines can effect occipital lobe in what way?
They can cause blurryness in vision, the more frequent the migraines are the more blurred ur visual field becomes, change sin brain in areas responsible for processing visual information
What are migraines? What can they be triggered by?
Is a change in blood pressure in brain can be triggered by weather changes.
What are potential aids to migraines?
Have drugs that hit both pain pathways as well as other pathways that drop blood pressure
What causes red green color blindness?
individuals are deficient in specific cells in the eyes that process these wavelengths. It is based on the
loss of a pigment in a cone in the retina.
What is the homunculus?
There’s a greater amount of brain surface area dedicated to larger part of the man then smaller parts
How do visual signals end in the cerebral cortex?
Go to visual receptors, thalamus, cerebral cortex
How do auditory signals end up in the cerebral cortex?
hit receptors, hindbrain, midbrain, thalamus, then cerebral cortex
How touch signals end up in the cerebral cortex?
Hit somatosensory receptors, spinal cord, brainstem, thalamus, and then cerebral cortex
What is the visible light spectrum?
wavelengths we can detect, small portion of all light, varies from 400 to 700 nm
What does light bend through?
The iris and lense
Why are iris and lense important?
allows you to see with greater acuity
What does light hit in the back part of your eye?
Retina
What is the retina made of?
Rods, cones, and cells responsible for transduction of photo signals to the primary visual cortex
When light enters eye what occurs?
You get stimulation of different cells which tranduce the information into nerves, that take info from eye, from back of retina, to visual cortex (occipital lobe)
Everything that you see is what?
An inverted version of everything. The brain just interprets it as right side up.
What focuses light?
The lense
What is the white of the eye?
The sclera
What is the fovea?
is the region of sharpest vision and has the densest distribution of photoreceptors specialized for color
What forms a blind spot in the eye? Why?
the optic disk (is where blood vessels enter eye and axons from optic nerve leave eye) has no receptors so forms blindspot. Is on retina
What does light go through as it enters eye?
bent first by cornea, travels through pupil, then bent again by lens, small muscles adjust curvature of lense to focus up close and far away
What is myopia?
nearsighted (can see things closer not far away)
What is hyperopia?
farsighted (can see things fara away not close)at
What determines if ur near sighted or farsighted? (TEST)
It depends on where the black dot appears on back of retina, nearsighted means that focus of eye happens prior to retina- gives negative score based on how far forward the light is, in farsighed ness you have larger plane of light on retina, as the black dot is further behind, measured in plus.
Foveal vision means? Is it more acute?
Is vision exactly where your staring, and yes is more acute
Why do we fill circle with yellow covering one eye?
Because our blind spot stops us from seeing the red, brain just fills it in with yellow to make sense
Why are we not always blind, why only covering one eye?
our optic disc is in a different location in each eye. The optic disc is lateral to the fovea in each eye, which means that it is to the left of the fovea in the left eye and to the right of the fovea in the right eye. Because the two eyes’ visual fields overlap, the right eye can see the left eye’s blind spot, and vice versa.
What are the specific receptors in brains that transmit info to the rest of the visual pathway?
Rods and cones, defines as receptors that are responsible for detecting color and fine detail (cones) and rods (black and white, used for night vision to see stuff with less stimuli)
Why do pupils dialate?
to let in more light so rods are stimulated
What happens when light hits back of retina?
You have cone and rods ending that take signals from light, excites them, the signal are transduced down the receptors which causes a confirmational change of proteins (rhodopsin) present which leads to signal transduction, to changes sin membrane ion permeability, to signals in optic nerve which lead to occipital lobe
What is optogenetics?
Uses opsins (protein) that can be stimulated with lights to turn off an on, allows you to manipulate cells and turn them off and on
What are the three types on cones?
blue, green, and red
Can other cones be activated by similar wavelengths?
Yes, but they have peak sensitivities at species values (blue cones at blue light) etc
Why are there few blue cones in eyes?
Because there’s so much blue so we need to tune it out
Is true blue common or rare?
rare
In order for signals to make it down to brain, many neurons are required what are they?
The amacrine cells (links bipolar and ganglion cells), bipolar cells (gets input from photoreceptors), horizontal cells (links photoreceptors and bipolar cells), makes up pathway between back of retina and retinal ganglion cells
What is retinal ganglion cell?
They give rise to the optic nerve (which tranduces info from back of eye to occipital lobe)
What are the three main routes to the visual brain?
The geniculostriate system, the tectopulvinar system, and the retinohypothalmic tract
What is the geniculo striate system? TEST
Projections from the retina to the lateral geniculate nucleus (of
thalamus) to the visual cortex
What is the tectopulvinar system? TEST
Projections from the retina to the superior colliculus to the
pulvinar (thalamus) to the parietal and temporal visual areas
What is the retinohypothalamic tract?
It a bunch of neurons in hypothalmus that help with circadian rhythm, tells us when to turn on and off
The LGN (lateral geniculate nuclues) of the thalmus has how many layers?
6 and they are fascitated in a striated fashion, home of P cells and M cells which correspond to rods or cones
All P cells send projections where?
To the LGN
Where do M cells send projections?
Through LGN or superiro colliculus (Tectopulvinar systems)
Where does the information in both geniculostriate systems and tectopulvinar systems end up?
Other visual cortical areas
What is the primary visual striate cortex (VI)?
in occipital lobe, is where all visual info ends up before an action is made
Why does everything go fuzzy in vision when you hit back of head?
Because the visual striate cortex gets rocked
Visual cortex has what when stained?
Has stripes, striated, has layers
Why is it important that visual cortex has layers?
Seeing a object close up gets stored in further up layer and matches it’s topographic layers.
What are the two visual streams?
Dorsal stream, Ventral Stream
What is the dorsal visual stream?
The how pathway (how
action is to be guided toward
objects), projects to the occipital cortex
What is the ventral visual stream?
projects to the temporal cortex, identifies an object (what pathway)
If you had injury in right side of brain where would you see effects?
In the left eye
How does info flow from eye?
Where does info flow from the eye on the side of the object? Oposite?
info from ipsaleteral side goes to LGN layers 2,3 and 5
info from contralateral side goes to LGN layers 1,4, and 6.
Layers 1 and 2 of LGN receice input from what?
M cell pathway
Layers 3, 4, 5, 6 recieve input from what pathway?
The P cell pathway
The seperation between the two eyes is maintaine dwhere?
In LGN V1
How does the LGN transfer info to the neocortex visual sub layers 5? What specifc layers to to what?
specific areas from LGN project to specific areas in visual cortex 1 (5-6 goes to alpha layer) (1-4 go to beta layer)
What are blobs in V1?
they are overabundance of mitochondria in within the blobs tissue, and these blobs make up large component of ability to see in color
What are interblobs?
in V1, responsible for form and motion perception
Memorize slide 28
Where does info from occipital cortex go to?
The temporal lobe (what pathway) and the parietal lobe (how pathway)
Is there vison beyond the occipital cortex? What about the temporal lobe?
Yes, there’s vision in parietal and temporal lobe, for temporal lobe is the fusiform face area which when damaged lead to facial agnosia and PPA to process senses
What is the visual systems in the parietal lobe?
lateral intraparietal area (LIP) contributes to eye movements; the
anterior intraparietal area (AIP) is involved in visual control of grasping; and the
parietal reach region (PRR) participates in visually guided reaching
Can you see with sound?
Yes, in the blind auditory cues cause activation in visual cortex (ex: when kid clicks)
