Brainscape's Knowledge GenomeTM

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


See full index

PSYC 363 - FUNDAMENTALS OF SENSATION AND PERCEPTION > Chapter 13 - Encoding Touch > Flashcards

Chapter 13 - Encoding Touch Flashcards

1
Q

Name the types of receptors found in the dermis and epidermis, and what each of them encodes.

A
  1. free nerve endings (pain)
  2. Merkel disks (touch)
  3. Krause end bulbs (touch)
  4. root hair plexus
  5. Meissner corpuscles (touch)
  6. pacinian corpuscles (pressure)
  7. Ruffini endings (pressure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe mechanoreceptors

A
  • They are bipolar neurons
  • their cell bodies are located in the dorsal root ganglion (right next to the spinal cord)
  • when pressure is applied, the pressure is transmitted to the receptor itself (the strain is what causes the cell to depolarize)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are mechanoreceptors?

A

Sensory receptors that transduce
mechanical deformations of the
skin into neural signals that are
sent to the brain

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

What are the three different kinds of mechanoreceptors?

A
  1. encapsulated receptors: Capsules surround the
    nerve ending, detect light touch, vibrations and
    constant pressure
  2. Separate Accessory Structure: Associated with types of
    epithelia cells, encode light touch
  3. Free nerve endings: No specialized terminal
    structures, responsible for detecting thermal changes
    and pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can we further categorize each of the three kinds of mechanoreceptors?

A
  1. Type of stimulation
    ‣ Pressure / Vibration / Temperature
  2. Size of the receptive field
    ‣ Area of the body that elects a receptor response
  3. Rate of Adaptation
    ‣ Fast versus slow
    - fast rates of adaptation encode changes in touch (like adjusting to a pair of socks)
    - slow rates of adaptation encode constant pressure (like holding a pen)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What mechanoreceptors belong to encapsulated neurons?

A 
Meissner Corpuscle
‣ Specialized nerve ending
associated with fast adapting
nerve fibers (FA I)
‣ Small Receptive Fields - Light
Touch
 Pacinian Corpuscle
‣ Specialized nerve ending
associated with fast adapting
nerve fibers (FA II)
‣ Large Receptive Fields -
Vibration
Ruffini Ending
‣ A specialized nerve ending
associated with slow adapting
fibers (SA II)
‣ Large Receptive Fields - Steady
Pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What mechanoreceptors belong to the separate accessory structure?

A

Merkel Cell Neurite Complex
‣ Specialized nerve ending associated with slow adapting
fibers (SA I)
‣ Small Receptive Fields - Light Touch

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

What does FA and SA stand for?

A 
FA = fast adapting
SA = slow adapting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is rate adaptation generally determined by?

A
  • size of receptor

- myelination

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

Name the slow adapting fibers?

A

Merkel and Ruffini - only respond to continuous pressure

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

Name the fast adapting fibers?

A

Meissner and Pacinian - will only respond to the onset and offset of pressure

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

If a receptor has a large receptive field, are we more or less likely to be able to locate where the stimulus is coming from?

A

Less likely, the opposite is true if the receptor field is small

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

Do receptive fields in the surface of the skin have smaller or larger receptive fields? What is the consequence of this on our ability to perceive the location of the stimulus?

A

Receptors in the superficial layers of the skin have small
receptive fields - fine detail
‣ Merkel and Meissner

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

Do receptive fields deep in the skin have smaller or larger receptive fields? What is the consequence of this on our ability to perceive the location of the stimulus?

A

Receptors in the deep layers of the skin have larger
receptive field - Course Details
‣ Ruffini and Pacinian

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

Are absolute thresholds for perceiving changes in pressure large or small?

A

Very small; facial areas are the most sensitive to pressure (mostly the nose, lip and cheek), extremities are not as sensitive

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

In what way can we assess spatial resolution?

A

Through the use of a two point touch threshold

17
Q

What mechanoreceptor is specialized for detailed perception of spatial patterns?

A

Merkel cells

18
Q

Which mechanoreceptor responds strongly to low frequency vibrations?

A

Meissner

- makes it ideal for perceiving slip and maintaining control over grip force

19
Q

Describe how Ruffini cells provide information on tactile sensitivity?

A 
How the hand is configured - flattened out on a table, rounded to pick up a glass
‣ Also plays a crucial role in encoding
movement across the skin
‣ Things moving across your hand
(or grasping objects) will pull and
stretch you skin
20
Q

What mechanoreceptor is very sensitive to high frequency vibrations?

A

Pacinian

  • very sensitive to amplitude
  • allows us to identify texture
21
Q

What is proprioception?

A

Perception of the position and movement of body
parts, based on the information in neural signals
from specialized sensors within those body parts

22
Q

What are proprioceptors?

A

Proprioceptors (muscle spindles, Golgi tendons,
and joint receptors) are found at the terminal ends
of nerve fibers
- are located in the muscles themselves and are either afferent or efferent
‣ Specialized at detecting stretching and contraction
of muscles

23
Q

What proprioceptor is mostly responsible for our proprioception?

A

Muscle spindles

24
Q

What is thermoception?

A

Sensory nerves that encode changes in temperature

  • either warm fibres (that fire with increases in heat between 29-43 degrees)
  • or cold fibres (that fire with decreases in heat between 17 to -40 degrees)
25
Q

What is physiological zero?

A

Where the cold and warm fibres meet, at 37 degrees for humans

26
Q

Describe thermoreceptors

A
  • Have relatively small receptive fields
  • They respond best to changes in temperature
    (contrast) and will adapt during prolonged
    exposure to a particular temperature
  • The rate of change will also affect their firing
    rate
    ‣ Small gradual changes will only evoke weak responses
    ‣ Large shifts in skin temperature (5 degrees a minute) will stimulate them maximally
27
Q

What is nocioception?

A

perception of pain

28
Q

What did Charles Scott Sherrington suggest?

A

First to suggest that pain perception stems from dedicated receptors sensitive to noxious stimuli
‣ Primary purpose is to quickly identify tissue damage

29
Q

What are nocioceptors and where are they located?

A

Nociceptors are free nerve endings located in the skin, joints, muscles and other organs

30
Q

How can we classify nocioreceptors?

A

Based on the type of stimulus they respond to

  • mechanical (cutting, tearing, pinching or punching)
  • thermal (intense heat or cold)
  • chemical aggression (corrosive acid)
31
Q

Why is pain perception so important?

A

It keeps us from further damaging ourselves

PSYC 363 - FUNDAMENTALS OF SENSATION AND PERCEPTION (22 decks)

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