Peripheral Somatosensory Mechanism Flashcards Preview

Jonathan's Neuroscience > Peripheral Somatosensory Mechanism > Flashcards

Flashcards in Peripheral Somatosensory Mechanism Deck (21):
1

What is the primary function of skin ridges?

provide grip (they also have receptors embedded within)

2

Mechanoreceptors tend to densely occupy what kind of skin?

glabrous skin

3

What are the four types of mechanoreceptors? What kind of information do they provide to the brain?

Meissner corpuscles + Merkel complexes close to the surface Ruffini organs and Pacinian corpuscles deeper in the skin conscious sense of touch

4

T/F Mechanoreceptors have the fastest conducting axons

false, muscle proprioceptors have faster conduction

5

Where are meissner and merkel receptors found?

at the dermal ridges close to the surface

6

Where can we find Ruffini corpuscle?

embedded in the connective tissue

7

Where can we find Pacinian corpuscle

in the dermis, very close to subcutaneous layer

8

Mechanorecpetors detect _________ and use receptors that have __________ nerve endings. They can detect up ________ and also _________ of force.

distortion of the skin encapsulated magnitude frequency

9

How does physical distortion get transduced to neural signal

The proteins are tethered to each other, so physically force can pull open a series of Na channels to create action potential.

10

What is the difference between slow and rapid adaptation

slowly adapting receptors encode the stimulus over a long time frame, whereas rapidly adapting receptors give the initial impulse upon activation

11

What is the difference between receptors for tactile information and pain?

the range of response and the threshold of activation for somatosensation are smaller

12

Which receptors are slowly adapting?

Merkel and Ruffini

13

Which receptors are rapidly adapting?

Meissner and Pacinian

14

In terms of receptor number, deeper receptors tend to be __________

less dense

15

Which mechanoreceptor is most numerous

Meissner

16

What do the four types of receptors primarily detect?

Meissner - transient response to skin movement Merkel - edge or indentation Ruffini - stretch and direction of stretch. Proprioceptive Pacinian - vibration

17

When picking up an object, what do the four receptors encode individually

Meissner - rate of force (change in surface contact) Merkel - grip force Pacinian - vibration Riffini - hand posture

18

What is a receptive field?

how much territory a single fibre respond to

19

Receptive fields often ________ , and where the receptive fields are dense, there is higher __________ . On our upper limb, there are denser receptive fields on the ________, and less dense in other parts 

Q image thumb

overlap

spatial resolution 

fingertip 

20

What is the difference between the signal transmission of nociceptor and mechanosensory receptor?

nociceptors make their first synapse in the spinal cord

21

Why do deeper receptors have larger receptive fields?

Because force radiates over longer distance, and deeper receptors can respond to singals that are off target