W03_04_Somatosensation beyond the DC/ML Flashcards Preview

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Flashcards in W03_04_Somatosensation beyond the DC/ML Deck (15):
1

name 4 cortical sensory modalities

graphesthesia,
stereognosis,
two-point discrimination,
double simultaneous stimulation

2

name of the receptor that responds to sound, light, tissue damage, temp, touch, pressure?

exteroceptor

3

name of receptor that monitors stimuli from viscera

enteroceptor

4

definition of receptor threshold?

stimulus intensity required to activate the receptor 50% of the time

5

threshold levels for tactile sensation?

low

6

threshold levels for pain?

high

7

function of rapidly adapting receptors?

report the onset/end of a stimulus;
for hi-freq vibration, mvt of objects across skin

8

function of slowly adapting receptors?

report continuously on stimulus;
for pressure, shape, lo-freq vibration, intensity of stimulus

9

size of types of SS nerve fibres?

Aalpha>Abeta>
Agamma>Adelta>
B>C

10

name 3 projections to other areas?

interneurons in dorsal horn (pain suppression);
medullary+pontine reticular formations (alerting responses and modifying locomotor reflexes);
superior colliculus (orienting reflexes)

11

how is sensation focused?

cortical descending inhibition;
lateral inhibition of unrelated interneurons;
these keep modalities separate

12

what are the 4 regions of the SI primary SS area?

cutaneous mechanoreceptors;
proprioceptors;
2x integration for differentiating texture, size, shape, motion

13

what is the SII secondary SS area important for?

tactile memory;
note that SII projects internally to the insula along the gyrus.

14

what are the inputs of SII area?

SI and thalamus;
outputs to temporal lobe via insula

15

where are visual and SS signals integrated?

sensory association area (posterior to postcentral gyrus);
projects to motor cortex for sensory-guided movement