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Flashcards in sensory physiology Deck (70)
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1
Q

what is modality and quality for sensory system

A

what is being sensed

2
Q

examples of Modality and quality

A
Vision
Audition
Balance
Somatosensation
Taste
Olfaction
Visceral
3
Q

what are the submodalities of somatosensation

A

Pressure
Pain
Temp

4
Q

what are the submodalities of taste

A
Sweet
sour
bitter
salty
Umami
5
Q

what is the intensity of a sensation

A

how much

6
Q

what is the lcoation of a sensation

A

where

7
Q

what is the duration of a sensation

A

When

8
Q

are all stimulus the same importance for each sesnory system

A

No

9
Q

where do unique expereinces associated with a particular modality begin

A

at the receptor

10
Q

what is the initial interaction of a stimulus with a receptor

A

transduction

11
Q

what is transduction

A

transformation of a physical energy into a neural signal

12
Q

the type of energy that a given receptor type is most sensitive to

A

adequate stimulus

13
Q

the stimulation site that elicit neural response

A

Receptive field

14
Q

types of thresholds

A

neural threshold

Perceptual threshold

15
Q

neural threshold

A

the amount needed to depolarizae a neuron

16
Q

preceptual threshold

A

absolute, difference

- how much it takes for one to notice

17
Q

law of specific nerve energyeis

A

Central connection determine modality

i.e. stimulation of optic nerve bypassing receptors mean light

18
Q

relates physical properiteis of stimulus to sensation

A

Psychophyscs

19
Q

what types of sesnations have sensory receptors on the primary afferent neuron

A

Somatosensory (mechanoreceptors, thermoreceeptors, chemoreceptors, nociceptors)
Olfaction (chemoreceptors)

20
Q

what types of sensations have sensory receptors on a recetpor cell that comunicates with the primary afferent neuron

A

Vision (photoreceptors)
Audition (mechanoreceptors)
Balance (mechanoreceptors)
Taste (Chemoreceptors)

21
Q

what is a physical (direct) interaction of a stimulus

A

what interaction with membrane preotein opens ion channels

22
Q

what senations do physical (direct) interaction

A

somatosensory
Vestibuluar
Auditory
taste

23
Q

what is a molecular interaction with a stiulus

A

interactions with a membran protein (G-protein)

24
Q

what sensations do molecular interaction

A

vision
taste
olfaction

25
Q

how does direction transduction occure in the taste system

A
  1. Na+ enters through ENaCs(epithelial Na+ channels): depolarization of cell
  2. Action potential leads to Ca++ entry
  3. Release of ATP as neurotransmitter (not stored in vesicles)
26
Q

what mechanoreceptors are used in direct transduction pathways

A

Piezo1 and piezo 2

27
Q

what are piezo1 and piezo2

A

A unique family of large + transmembrane segments for direct transduction

28
Q

key evidence of piezo 1 and piezo2

A

Dorsal Root Ganglion cell
Response to pressure
Knockouts show reduced response

29
Q

what is TRP receptors

A

A direct transduction pathway of 31 types with 8 families

30
Q

full name for TRP recptors

A

TRansient Receptor Potential receptors

31
Q

discovery of TRP receptors

A

Family of ion channels first found in Drosophila then mammalian cells

32
Q

what makes up TRP receptors

A

6 transmembrane domains with channel between 5 and 6

33
Q

actions of TRP receptros

A

cation ion channels that can pass Ca++

34
Q

activation of TRP receptors

A

large variety of activating mechanisms

  • intracellular Ca++
  • temp
  • chem
  • sound
  • light
  • pH
  • osmolarity
  • mechanical can open
  • different TRP channels
35
Q

what does the VAnilloid REceptor (TRPV1 or V1 respond to

A

capsaicin
heat ( >42 degrees C)
Protons

36
Q

Stimulation of Vanilloid REceptor (TRPV1 or V1) leads to

A

influx of cations (Na+ and Ca++)

37
Q

types of Indirect G-protein coupled receptors for olfaction

A

300-650 types

  • Golf
  • Gs
    • 2 large families
38
Q

types of Indirect receptors for vision

A

a dozen types
Rhodopsin (rods)
Photopsins (cones)

39
Q

Types of Indirect receptors for taste

A

Gustductin

40
Q

what submodality of taste does Molecular G-proteins work for

A

Taste

41
Q

how does Molecular G-protein reception work for sweet taste

A

Sugars bind to REceptor coupled G-protein
Release of intracellular Ca++ activates TRPm5 channel (TRP)
Depolarization leads to AP and relase of Neurotransmitter ATP

42
Q

general steps for coding for intensity

A

Increase in stimulus intensit
Increase in receptor potential
Increased number of APs

43
Q

Correlation between neural response and Human perception

A

increased firing rate is directly related to perceptual response

44
Q

what is THreshold

A

Not a precise value;

A statistical concept as a stimulus intensity dected on 50% of trials

45
Q

what affects the threshold

A

not only a funtion of stimulus

- can be affected by psychological, neurological, or pharmacological factors

46
Q

uses of threshold

A

Diagnostic tool

47
Q

High odor threshold is predicitive of what

A

Alzheimer’s disease

48
Q

how was it determined that high odor threshold predictive of alzheimer’s disease

A

Elderly patients tested in an odor threshold test
Cognitive test 1 yr after testing
PAtients with alzheimer’s had higher thresholds in the earlier olfaction threshold test

49
Q

receptive field

A

what a receptor (or neuron) is sensitve to

50
Q

what happens to location and intensity in a single neuron

A

Location and Intensity are confounded

51
Q

roll of LAteral inhibition

A

Improves spatial localization( neurons lateral to a stimulus inhibit each other, so that only strong stimulus’s produce lots of AP

52
Q

do indiviusal fibers respond to Odors

A

Noyt, specifically tuned, but are more broadly tuned

53
Q

how do we get an infinite amount of odor qualities

A

Comparing activity across olfactory fibers

54
Q

when are rapidly adapting singals important

A

for rapidly changing stimuli such as virbation or moving stimul

55
Q

when is slowly adpating singalling important

A

for prolonged events (joint and muscle receptors that help maintain upright posture, provide signal for sustained pressure)

56
Q

what does Presynaptic excitation or inhibition lead to

A

more or less Ca++ enry to modulate neurotransmitter release

57
Q

the auditory pathway

A
  1. Hair cells (receptor cells) in cochlea (inner ear)
  2. Innervation by VIII nerve
  3. VIII nerve synapses in cochlear nuclei
  4. Ascending sensory pathway to cortex
  5. Efferent pathway from superior olivary nuclei
58
Q

what is the Auditory Efferents

A

Efferents from the superior olive synapse on hair receptor cells

59
Q

what is the synapse of the superior olive on hair receptors

A

is an inhibitory nicotinic receptor (Ca++ activated K+ Channels leading to hyperpolarization

60
Q

roll of auditory efferents

A

functions to set gain of receptor neuron to respond to different kinds of auditory events

61
Q

what is held in the olfactory cortex

A

frontal cortex

62
Q

where is the auditory cortex

A

Temporal lobe

63
Q

where is the somatosensory cortex

A

PArietal lobe

64
Q

where is the taste cortex

A

Insular cortex

65
Q

where is the visual cortex

A

Occipital lobe

66
Q

what is the somatotopic map

A

the body representation of neurons

67
Q

what is the Tonotopic map

A

auditory pitch representation

68
Q

what is the Retinotopic map

A

Visual field representation

69
Q

are sensory maps all the same

A

No dynapmic (plastic)

  • experience
  • Neurological injury
70
Q

what happens to the cortical area if you over stimulate 3 and 2 digits

A

the 3rd and 2nd digit areas becomes larger (Central sprouting)