Brainscape's Knowledge GenomeTM

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


See full index

Neuroscience > Peripheral sensory mechanisms > Flashcards

Peripheral sensory mechanisms Flashcards

1
Q

What type of skin covers the palms of the hands and the soles of the feet?

A

Glabrous skin

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

What is glabrous skin specialised for?

A

Somatosensation

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

How is glabrous skin specialised for somatosensation?

A

Skin ridges

Concentrated with receptors

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

Which broad class of receptors are found in glabrous skin?

A

Mechanorecptors

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

Which four types of mechanoreceptors are found in glabrous skin?

A

Meissner corpuscles

Merkel complexes

Ruffini organs

Pacinian corpuscles

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

Describe the location of the mechanoreceptors in the skin?

A

Meissner corpuscles and Merkel complexes are located close to the surface

Ruffini organs and Pacinian corpuscles are deeper

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

Describe the axons that innervate the mechanoreceptors?

A

Large and myelinated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where do the cell bodies of the axons that innervate mechanoreceptors lie?

A

In dorsal root ganglia

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

What are the endings of mechanorecepptors composed of?

A

Connective tissue

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

What are the connective tissue endings of each type of mechanoreceptor important for?

A

Determining the type of energy that the receptor will respond to

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

Which layers of the skin are the Ruffini and Pacinian corpuscles located in?

A

Ruffini corpuscles are located in the dermis

Pacinian corpuscles are located in the subcutaneous layer

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

What are the Ruffini and Pacinian corpuscles embedded in?

A

Connective tissue

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

Which receptors detect distortion of the skin?

A

Mechanoreceptors

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

What is the range of distortion detected by the mechanoreceptors?

A

10nm to sub-damaging distortion

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

What is the sensitivity and dynamic range of the mechanoreceptors to distortion of the skin?

A

0-1000 Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the receptove field of the mechanoreceptors that detect distortion of the skin?

A

10mm^2 to entire hand

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

How do mechanoreceptors respond to mechanical distortion?

A

Mechanical distortion > Na channels opened by mechanical force > Na inflow > AP generated

18
Q

Describe why radiating forces are important for mechanoreception?

A

Force applied to skin radiates > at some point, the mechanoreceptor will experience some of that force > generate AP if stimulus reaches threshold

19
Q

When will a mechanoreceptor generate an AP?

A

When the stimulus applied is strong enough to generate a large Na inflow that reaches threshold

20
Q

What happens if a stimulus does not cause Na to reach threshold?

A

No AP generated > we have no sensory experience of the event that is occurring

21
Q

Describe the difference between slowly adapting and rapidly adapting receptors?

A

SLOW: Show an initial bit of enthusiasm in response to a stimulus

Over time, encode the size of the stimulus

RAPID: Short initial excitement

After that, only respond when there is a change in stimulus

22
Q

Does the nervous system generally act like slowly adapting or rapidly adapting receptors?

A

Rapidly adapting

23
Q

Which of the mechanoreceptors are slowly adapting? Which are rapidly adapting?

A

Slowly adapting: Merkel complexes and Ruffini organs

Rapidly adapting: Meissner corpuscles and Pacinian corpuscles

24
Q

Where are Merkel complexes and Meissner corpuscles located?

A

Merkel complexes are located at the tips of epidermal ridges

Meissner complexes are found near the skin surface

25
Q

Which particular stimuli do each of the four mechanoreceptors respond to?

A

Merkel: indentation

Meissner: transient response to skin movement

Ruffini: sustained response to skin movement

Pacinian: transient response to vibration

26
Q

What types of connections do the axons of mechanoreceptors have in the spinal cord?

A

Local connections and ascending projections to the brain

27
Q

Describe the difference in firing rate between tactile and nociceptive primary sensory afferents?

A

Tactile: don’t change firing rate with increased force

Nociceptive: increased firing rate with increased stimulus, as well as increased firing once stimulus is removed

28
Q

Describe the receptive fields of each of the four types of mechanorecptor?

A

Merkel: small, high density

Meissner: small, high density

Ruffini: large, low density

Pacinian: large, low density

29
Q

Why are all four mechanorecpetors required?

A

To build a profile of information and make judgements about what we are touching/feeling

30
Q

When performing a simple manipulation task, what do each of the four mechanoreceptors encode?

A

Meissner: rate of force

Merkel: grip force

Pacinian: vibrations

Ruffini: hand posture

31
Q

How does firing from each of the four mechanoreceptors change throughout a simple manipulation task?

A

Meissner and Pacinian have bursts of activity when there is change (rapidly adapting)

Merkel and Ruffini provide sustained information (slowly adapting)

32
Q

What are the mechanoreceptors located in muscles called?

A

Muscle spindles

33
Q

What does the two-point discrimination threshold describe?

A

Measures how much territory a single receptor is responsive to

34
Q

Why does the two-point discrimination threshold vary across the body?

A

Size of receptive fields varies across the body

Small receptive fileds > can discriminate well

35
Q

How does two-point discrimation vary between areas with large receptive fields and areas with small receptive fields?

A

Large receptive fields > hard to discriminate between two points

Small receptove fields > easier to discriminate between two points

36
Q

What is the conduction velocity of the mechanoreceptors?

A

35-75 m/s

Fast

37
Q

What is the axon diameter of the mechanoreceptors?

A

6-12 um

Large

38
Q

Why are dermatomal patterns different to spinal nerve distribution?

A

Presence of anastamoses

39
Q

Describe the endings of nociceptors?

A

Free nerve endings

40
Q

How does the spinal cord arrangement differ for mechanoreceptors and nociceptors?

A

Mechanoreceptors have an ipislateral arrangement

Nociceptors have a contralateral arrangement

41
Q

Describe the spinal cord connections of nocicpetors?

A

Make their most significant connections in the spinal cord at the level that they enter

Neuroscience (51 decks)

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