Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroscience > L22 Sensory Systems > Flashcards

L22 Sensory Systems Flashcards

1
Q

describe the common plan of sensory systems

A
  • designed to detect a physical stimulus (light, sounds etc.)
  • stimulus is translated/signal transducted into cell activities into sensory receptor cells/neurons/transducers
  • sensory receptor cells pass the signal onto second order neurons
  • passes through thalamus (relay station)
  • info reaches cerebral cortex - (sensory = parietal, occipital, temporal, insular)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the components of the common plan of sensory systems?

A

stimulus – receptor – pathway – perception/behavior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

in what part of the brain does sensory info reach consciousness?

A

cerebral cortex - trigger behavior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define perception

A

the process of interpretation of sensory input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the 6 sensory systems?

A
  • somatosensory
  • visual
  • vestibular
  • auditory
  • olfactory
  • gustatory

*olfactory and gustatory are closely related = chemical senses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the 4 basic sensory receptor classes?

A

mechanoreceptors - pressure on skin
thermoreceptors - sense temp changes
chemoreceptors - sense chemical changes
photoreceptors - sense light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what sensory receptor classes does the somatosensory system need

A
  • mechanoreceptors
  • thermoreceptors
  • chemoreceptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what sensory receptor classes does the visual system need

A

photoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what sensory receptor classes does the vestibular system need

A

mechanoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what sensory receptor classes does the auditory system need

A

mechanoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what sensory receptor classes does the olfactory system need

A

chemoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what sensory receptor classes does the gustatory system need

A

chemoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the components of a sensory receptor

A

cell body - soma, perikaryon
t
ransduction site - stimulus is converted to nerve signal

axon
synaptic terminal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what morphology (type) of neurons are somatosensory receptors?

A

pseudo-unipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is a receptor potential

A

“graded potentials” = do not follow “all or none rule”

  • variable durations and intensities
  • variability lies in the number of AP per unit time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

where do receptor potentials take place

A

transduction site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is an action potential

A

stimulus conducted from distal to proximal axon to synaptic terminal

*note - in sensory receptor neuron, AP are NOT generated in axon hillock like seen in multipolar motor neurons

18
Q

where do action potentials take place

A

trigger zone

19
Q

what are transmitter release

A

transmitter is released into cleft and binds to receptors within the postsyn membrane of the postsym cells = second order neuron of the sensory pathway

20
Q

where does transmitter release take place

A

synaptic terminals of sensory receptor

21
Q

what are the morphological characteristics of sensory receptor cells?

A
  • example - hair cell
  • specialized epithelial cells (not neuronal origin)
  • apical pole is transduction site
  • lack an axon
  • do NOT produce AP
  • have graded potential that directly induces the release of signaling substances at the base of these cells
  • form a synapse onto an afferent (sensory) fiber of the first neuron in the sensory pathway => neuron produces AP carried along its afferent fibers!
22
Q

what are the 4 attributes of stimulus

A

modality
intensity
duration
location

23
Q

define modality

A

the physical type (quality) of stimulus energy - may be light (visual system), sound (auditory system), touch (somatosensory system) etc.

24
Q

Define intensity

A

the amplitude (or quantity) of a stimulus

25
Q

define duration

A

the time between the start and the end of a stimulus

26
Q

define location

A

the place where the stimulus is located or originated - maybe some place in our 3D environment around us (light or sound) or a place on the surface of our body (touch)

27
Q

how is modality encoded?

A

labeled line code - pathways carrying sensory information centrally are therefore also specific, forming a “labelled line” regarding a particular stimulus

28
Q

how is intensity encoded?

A
  • subthreshold stimuli may elicit a small receptor potential but may not induce an AP
  • frequency code
  • population code
29
Q

what is frequency code in wrt intensity encoding

A

assuming receptor potentials are above threshold, the higher the stimulus intensity is the more AP will be generated per unit time

applies to individual neurons and their axons

30
Q

what is population code wrt intensity encoding

A
  • high intensity stimuli can activate more individual axons than a low intensity stimulus
  • example -press harder and harder on your hand = stimulates a larger area thus more axon stimulation
31
Q

how is duration encoded?

A

-receptor adaptation - the disappearance of a sensation induced by a stimulus when the duration is too long
example => disappearing feeling of wearing clothes all day even though you felt them when you put them on
-slow adapting receptors
-rapid adapting receptors

32
Q

what are slow adapting receptors wrt duration encoding

A
  • used for constant monitoring
  • important for regulatory function of tight physiologic windows
  • they remain depolarized for the duration of the stimulus and maintain a constant output of APs
33
Q

what are rapid adapting receptors wrt duration encoding

A
  • only signal at the onset of stimulus where the receptor potential quickly returns to baseline
  • no further APs are generated despite the persistence of the stimulus
  • much better equipped for sensitivity to changes and not constant stimulation
34
Q

what receptors are better in constantly monitoring levels of stimulation wrt duration

A

slowly adapting receptors

35
Q

what receptors are most sensitive to changes, not to constant stimulation?

A

rapidly adapting receptors

36
Q

define receptive field wrt location

A

the area monitored by a single neuron = the area where a stimulus would induce a response

37
Q

what happens if a stimulus is placed within the receptive field?

A

AP!

38
Q

what happens if a stimulus is placed outside of the receptive field

A

never be an AP on that neuron

39
Q

what are the 3 basic wiring mechanisms

A
  • convergence
  • divergence
  • lateral inhibition
40
Q

what is convergence?

A
  • when a second order neurons gets input from more than 1 first order receptor neuron
  • the inputs will summate and give a larger summation than the parts alone
41
Q

what is divergence

A

the signal from 1 first order neuron stimulates multiple second order neurons

42
Q

what is lateral inhibition

A

a situation where a first order neuron stimulates an interneuron which will relay that stimulus to an adjacent second order neuron only it is inhibiting that adjacent neuron

Neuroscience (54 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions