Touch

Question 1

what are the 3 main types of mechanically gated cation channels on mechanoreceptors

Answer 1

stretch sensitive
linking protein
g protein coupled

Question 2

what does fast adaptation mean

what types of mechanoreceptors are fast adapting

Answer 2

means that when stimulus is sustained, then the firing rate of a mechanoreceptor will cease quickly
______ corpuscle = fast adapting.

Question 3

where are mechanoreceptors with smaller receptive fields located

Answer 3

near skin surface

Question 4

describe merkel cells in terms of
location
receptive field size
adaptation rate
threshold for indentation/vibration

Answer 4

skin
small
slow
large

Question 5

describe meissner corpuscles in terms of
location
receptive field size
adaptation rate
threshold for indentation/vibration

Answer 5

skin
small
rapid
low

Question 6

describe PACINIAN corpsucles in terms of
location
receptive field size
adaptation rate
threshold for indentation/vibration

Answer 6

below skin surface
large
rapid
low

Question 7

describe ruffini endings in terms of
location
receptive field size
adaptation rate
threshold for indentation/vibration

Answer 7

deep in skin
large
slow
large

Question 8

what accounts for pacinian corpuscles’ fast adaptation rate and responsiveness ot high freq ap’s

Answer 8

concentric connective tissue structure

Question 9

describe how mechanoreceptors connect to PSC

Answer 9

sensory axon –> soma (DRG) –> dorsal root
may synapse in dorsal root, or continue to dorsal column nucleus and synpase here; then neuron goes to VP of thalamus; which connects to PSC

Question 10

other names for PSC?

Answer 10

area 3b, S1

Question 11

describe somatotropic map

Answer 11

adjacent regions of skin are generally represented as adjacent regions of cortex, but some discontinuity (eg. genitals next to face)

Question 12

better discrimination performance occurs for

Answer 12

higher receptor density/larger coritcal representation

small receptive fields