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Neuro Test 1
1/27 Sensory transductin
34
Dentistry
Graduate
01/30/2014

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Cards

Term
What are the 4 attributes of a stimulus?
Definition
MODALITY (vision, hearing, somatosensory)

INTENSITY (how loud, bright, painful)

DURATION (how long or short it happens)

LOCATION
Term
What type of response is there only when the stimulus is turned on or off and doesn't use as much energy?

What type of response is there the entire period the stimulus is present but is metabolically costly?
Definition
transient response

sustained response

(nervous system uses both)
Term
If the modality is vision, what is the stimulus energy, receptor class, and receptor cell type?
Definition
Light

photoreceptor

rods, cones
Term
If the modality is hearing, what is the stimulus energy, receptor class, and receptor cell type?
Definition
sound

mechanoreceptor

hair cells (cochlea
Term
If the modality is balance, what is the stimulus energy, receptor class, and receptor cell type?
Definition
Gravity

mechanoreceptor

hair cells (vestibular labyrinth)
Term
If the modality is touch, what is the stimulus energy, receptor class, and receptor cell type?
Definition
pressure

mechanoreceptor

cutaneous mechanoreceptor of dorsal root ganglion neurons
Term
If the modality is proprioception, what is the stimulus energy, receptor class, and receptor cell type?
Definition
displacement

mechanoreceptor

muscle and joint receptors of dorsal root ganglion neurons
Term
If the modality is temperature sense, what is the stimulus energy, receptor class, and receptor cell type?
Definition
thermal

thermoreceptor

cold and warm receptors
Term
In the somatosensory sense, what type of ganglion/receptor do you expect?
Definition
a single afferent fiber with transduction occurring in a specialized region of the axon (simple)
Term
In the auditory/vestibular sense, what type of ganglion/receptor do you expect?
Definition
mechanoreceptors are specialized hair cells which transduce/signal second order motor neuron which generates AP and transmits information to the brain
Term
In the visual system, what type of ganglion/receptor do you expect?
Definition
photoreceptor signals to interneuron (bipolar) cells using graded potential and then synapses the retinal ganglion cells (third order cell)
Term
What is the only way the brain knows how to interpret series of action potentials?
Definition
location of the labeled line to the axonal trajectories of the cells (AP of different sensory modalities are the same)
Term
Mechanoreceptor, chemoreceptor, or photoreceptor:

pore is usually closed when not stimulated but opens when there is a stimulation causing nonspecific flow of Na and K which depolarizes the cell
Definition
mechanoreceptor (direct)
Term
Mechanoreceptor, chemoreceptor, or photoreceptor:

Receptor-ligand (2nd messenger-cAMP) interaction produces channel opening
Definition
chemoreceptor (olfactory and certain gustatory)
Term
Mechanoreceptor, chemoreceptor, or photoreceptor:

In response to light, there is a decrease in cGMP and channels close (hyper polarize rods and cones)
Definition
photoreceptor
Term
In a mechanoreceptor that is a stretch receptor, do you (increase or decrease) depolarization with increasing stretch?

Do receptor potential (increase or decrease) as you apply more force on the membrane?

Do the channel open (wider or longer) in response to more pressure?
Definition
increase

increase

longer (longer amount of pressure=open longer, short amount=open and close quickly)
Term
Hair cells found in the auditory and vestibular system are very sensitive to sounds and vestibular stimuli but they rely on ______________.
Definition
mechanoreceptors
Term
As the stereocilia move toward the kinocilia, the hair cell will (depolarize or hyper polarize)

If they move away, the hair cell will (depolarize or hyper polarize)
Definition
depolarize

hyperpolarize
Term
__________ connect channel gate to adjacent taller stereocillium, thus increasing the probability that the channel will open.
Definition
Tip links (mechanical amplification system-makes hair cells sensitive)
Term
In vision, what is the 2nd messenger?

What is the membrane channel?

What is the sensory response (channel open or close)?

Cell body output?
Definition
cGMP

cationic: inward current

closed channel

synapses
Term
In olfaction, what is the 2nd messenger?'

open or closed channel?

cell body input?
Definition
cAMP

open channel

impulses (direct signal)
Term
Do sweet/bitter or salt/sour transduction use Na and K channels (not much signaling)?
Definition
salt/sour
Term
Do sweet/bitter or salt/sour transduction use cAMP amplification system?
Definition
sweet/bitter
Term
In mechanoreception, is there a synaptic or impulse (direct) cell body input?
Definition
synaptice
Term
When comparing stimulus detection and stimulus intensity, what shape would you expect the graph to be?
Definition
sigmoid (the stronger the intensity, the more likely you will detect it)
Term
What is the lowest level at which a given stimulus can be detected?
Definition
absolute sensory threshold (A stimulus that is less intense than the sensory threshold will not elicit any sensation)
Term
Ideally, you can plot stimulus intensity in (linear or logarithmic) terms and discharge.

What does this allow?
Definition
logarithmic (If it is 10x brighter or louder, it may fire a factor of 2-3x more, not 10x)

can code over large magnitudes of stimulation intensities
Term
What is the only sensory system that does the opposite of ideal -- when you double the stimulus, it is perceived as 8-10x more powerful?
Definition
pain (intensity of electric shock exponent=3.5; easy to feel pain)
Term
What are the 2 types of adapting receptors?
Definition
rapidly adapting (signals on and off)

slowly adapting sustained signal (increase firing when stimulus is on, decrease a little due to adaptation but maintains fairing as stimulus is on)
Term
Rapidly adapting cells can follow (high or lower) frequency stimulation
Definition
higher
Term
What is any region whereby the stimulus will change the activity/firing rate (increase or decrease) of the neuron for somatosensory and visual?
Definition
receptive field
Term
What type of receptive field is in the cochlea?
Definition
frequency tuning (one region of the cochlea is most sensitive to a stimulus that would be the intensity needed to a induce a response)
Term
What does lateral inhibition in somatosensory and visual increase?
Definition
increase in the contrast between the stimulation of the primary cell and inhibition of the surrounding cells = sensory transduction
Term
In the somatosensory system, what is mostly represented in the thalamus and cortex?

In the visual field map, what is most of this area devoted to?
Definition
mouth, tongue, and tip of index finger

central 10 degrees of the visual field (little devoted to visual periphery beyond 40 degrees)

(Each organism has specific magnifications that they use for processing)
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