Touch

Question 1

somatosensation

Answer 1

blanket term for touch

the collective sensory signals from skin, muscle, tendons, joints, and other internal receptors

Question 2

2 receptors included in somatosensation

Answer 2

proprioception
- our sense of where our body moves

kinesthesia
- our sense of how our body moves through space

Question 3

difference between proprioception and kinesthesia

Answer 3

pro - sense of body

kin - more about body movement through space

Question 4

do you know where your nose is?

this is considered __________

now touch your nose

this is considered ________

Answer 4

proprioception; kinesthesia

Question 5

outer layer of the skin

Answer 5

epidermis

Question 6

secondary layer of the skin

Answer 6

dermis

Question 7

3 criteria of tactile receptors

Answer 7

type of stimulation to which they respond

size of their receptive fields

rate of adaptation (fast vs. slow)

Question 8

fast vs slow rate of adaptation in touch

Answer 8

fast - quick touch

slow - ex. forget what the clothes on your body feel like since they have been in contact for a while

Question 9

4 tactile mechanoreceptors

Answer 9

meissner corpuscles
merkel discs
pacinian corpuscles
ruffini endings

Question 10

meissner corpuscles

Answer 10

low frequency vibrations and grasp stability

• fast adapting (FA I Fibers)
• small receptive fields
• close to the surface of skin

Question 11

merkel discs (neurite complexes)

Answer 11

coarse texture and pattern

• slow adapting (SA I Fibers)
• small receptive fields
• close to the surface of the skin

Question 12

pacinian corpuscles

Answer 12

high frequency vibrations and fine texture

• fast adapting (FA II Fibers)
• large receptive fields
• deep in the skin

Question 13

ruffini endings

Answer 13

finger position

• slow adapting (SA II Fibers)
• large receptive fields
• deep in the skin

Question 14

tactile receptors closer to the surface have … (2 things)

Answer 14

smaller receptive fields
higher acuity

Question 15

tactile receptors not close to the surface have … (2 things)

Answer 15

large receptive fields
low acuity

Question 16

what does myelination do to neurons

Answer 16

coating allows for signals to get across faster

Question 17

a-alpha fiber/associated receptor

Answer 17

fastest with the most myelination; proprioceptor

Question 18

a-beta fiber/associated receptor

Answer 18

2nd fastest, good amount of myelination; mechanoreceptor

Question 19

a-delta fiber/associated receptor

Answer 19

3rd fastest, a little myelination; pain and temperature

Question 20

c fiber/associated receptor

Answer 20

slowest fiber, no myelination; pain, temperature, itch

Question 21

our muscles, tendons, and joints also have mechanoreceptors for ______ & ________

Answer 21

kinesthesia; proprioception

Question 22

muscle spindle

Answer 22

inside our muscle wrapped around it to sense as muscle contracts to allow brain to regulate tension

Question 23

people who have a loss of proprioception are unable to …

Answer 23

coordinate properly

Question 24

thermoreceptors

Answer 24

separate warm and cold fibers that cover different ranges of temperatures (non-painful temps)

Question 25

thermoreceptors have ion channels that respond to ________ changes as well as some that respond to ________

Answer 25

temperature; chemical

Question 26

what are thermoreceptors generally measured in comparison to your actual ...

Answer 26

skin temperature

Question 27

cold fibers have a _____ range while warmth fibers have a _____ range

Answer 27

wider; sharper

Question 28

nociception

Answer 28

pain, can detect damage, excessive heat/cold, chemical/noxious stimuli

Question 29

2 types of nociception/pain fibers

Answer 29

a-delta - medium sized, myelinated to quickly transmit pain and temperature information - quick sharp pain (ex. when someone stabs you) c-fiber - narrow, unmyelinated that transmit a slower signal of pain and temperature information - slower, throbbing sensation to make you aware that you are still hurt

Question 30

TRPs

Answer 30

thermo and chemical receptors type of receptor dictates type of sensation

Question 31

nociception is at the ____ of the temperature scale

Answer 31

ends

Question 32

if you lack a-delta fibers, you will ...

Answer 32

know you are in pain but won't be able to identify where exactly it hurts

Question 33

if you lack c fibers, you can ...

Answer 33

tell someone you have been hurt but won't feel it long term

Question 34

tactile information passes to the _____ ____ of the spinal cord before extending up to the brain

Answer 34

dorsal horn

Question 35

spinothalamic pathway

Answer 35

spine --> thalamus carries the slower signals, generally about skin temperature and longer pain

Question 36

dorsal column-medial lemniscal (DCML) pathway

Answer 36

carries the faster signals from skin, muscles, etc. supports proprioception need to constantly be sensing your body position, so needs to be fast

Question 37

which pathway is faster: spinothalamic or DCML

Answer 37

DCML

Question 38

what type of organization does the somatosensory cortex maintain?

Answer 38

somatotopic

Question 39

another word for somatotopic

Answer 39

homunculus: a body map in the brain

Question 40

is the homunculus 1-to-1? subject to remapping?

Answer 40

no; yes

Question 41

what does the homunculus do to areas that need to be particularly sensitive, similar to the fovea

Answer 41

cortical magnification

Question 42

2 major networks for touch/pain in the brain

Answer 42

sensory-discriminative - S1, etc. your basic sense of touch emotional-aversive: anterior cingulate, PFC - more tied to pain responses - also cognitive/emotional aspects - helps down regulate pain if need to power through

Question 43

pain can be heavily modulated by ________ and ________ factors

Answer 43

emotional; cognitive

Question 44

gate control theory

Answer 44

pain can incorporrate modulating signals from the brain, and can even be blocked by other local signals at the dorsal horn of the spine, such as from rubbing or scratching ex. if you were bit by a mosquito, you can block the pain temporarily by itching it

Question 45

analgesia

Answer 45

pain relief, come in many forms

Question 46

hyperalgesia

Answer 46

heightened response to pain consequence of an injury can get ongoing pain from issues in the nervous system: neuropathic pain

Question 47

neuropathic pain

Answer 47

pain system malfunction

Question 48

touch is relatively ______

Answer 48

fast

Question 49

touch is faster than ______ but slower than ______

Answer 49

vision; hearing

Question 50

haptic perception

Answer 50

knowledge of the world derived from info about touch and proprioception know how to position hand to grab something and know what most things feel like before touching it

Question 51

different materials produce different ____

Answer 51

timbres

Question 52

course materials, like sandpaper, are perceived by _____ fibers

Answer 52

SA I

Question 53

finer materials, like fabric, are perceived by _____ fibers

Answer 53

FA II

Question 54

the FA II afferents fire in _____ with the vibrations from the fabric as it moves across the skin

Answer 54

synchrony

Question 55

haptic guide action

Answer 55

our experience of touch and proprioception allow us to pre-plan actions and maintain actions

Question 56

haptic object knowledge

Answer 56

aka "What" system can recognize objects by their 3D properties but can't recognize a 2D outline of an object

Question 57

what features pop out during haptic search? what don't?

Answer 57

do: rough vs smooth, hard vs soft, cool vs warm don't: shifts in the same texture (horizontal to vertical lines)

Question 58

why is braille raised dots and not letters? why do we trace them with our fingertips?

Answer 58

we are bad at identifying 2D objects; maximum acuity at the fingertips

Question 59

tactile agnosia

Answer 59

inability to recognize objects via touch, usually in one hand (**contralateral** to the damage)

Question 60

is visual object recognition fine with tactile agnosia?

Answer 60

yes

Question 61

the "where" system of touch

Answer 61

you have some knowledge about here things are via touch, can often find your alarm in the morning without seeing it evidence that, like vision, this system is tied to the parietal cortex

Question 62

hemineglect extends to ...

Answer 62

touch and proprioception

Question 63

example of sensory integration

Answer 63

rubber-hand illusion