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Neuro Block 2-RG > Sensory Pathology > Flashcards

Flashcards in Sensory Pathology Deck (20)
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1

What are the 3 fundamental steps in information processing?

-transduction
-transmission
-perception

2

What is nociception?

stimulation of nerve cells

3

What are the required steps of transduction?

1. stimulus
2. receptor w/ transducer protein present
3. ion channels open or close
4. membrane potentials change
5. AP generation

4

With regard to tranduction, where does the first AP occur?

first node of Ranvier

5

What are the two types of receptors for sensation and how do they act?

-somatosensation: 1˚ afferent has receptors
-special senses except olfaction: receptive cells releases neurotransmitter onto 1˚ afferent

6

What is a receptive field?

spacial region where a stimulus will produce a response (dendrite-defined)

7

What is a sensory unit?

1˚ afferent + all receptive cells that define its receptor field

8

What is s stimulus modality?

receptors responding to one type of stimulus preferentially

9

What is an adequate stimulus?

stimulus TYPE that is the correct modality for a receptor to interpret

10

What are the three types of energy we can sense?

mechanical
chemical
electromagnetic

11

What is a nonadequate stimulus?

stimulus not of normal modality for receptor, may be perceived incorrectly as adequate stimulus (conditioned response)

12

2 ways stimulus intensity can be increased

-frequency
-population (# of cells)

13

Frequency coding

increased # of APs

14

Population coding

receptive field overlap

15

Tonic adaptation

slow adaptation

16

Phasic adaptation

fast adaptation

17

What is the inherent problem with acuity?

larger receptive field = decreased acuity
more receptors stimulated, less acute interpretation

18

Where does lateral inhibition occur?

in CNS

19

Describe lateral inhibition

most stimulated neurons inhibit the signal of adjacent neurons to make the localization of the sensation more acute

20

What is the test designed to test touch acuity?

two point discrimination test