Touch & Pain Flashcards
Hottest known pepper
Pepper X
acupuncher
needles in face for back pain
How old was Ian
19
What were Ian’s symptoms
couldn’t feel limbs or walk/sit
If not looking, couldn’t tell where limbs were
could not move purposfully
Who was the man who lost his body
Ian
True or False?
Ian could move his limbs when he could see them
true
What did Ian have
proprioception
autoimmune disease that kills viruses and proprioceptors
proprioception
All sensory processing begins in _____ cells
receptor
How can a single neuron convey intensity of signal
changing the frequency of its action potentials
What is the downside of using a single neuron to convey the intensity of a signal
a neuron can only fire so fast
How can multiple neurons convey the intensity of a signal
as the stimulus strengthens, more neurons are recruited
How can different neurons be used to convey intensity of a stimulus
different neurons respond to different ranges
We use all three methods of conveying stimulus intensity in which systems
vision
hearing
touch
Which sensory system evolved first
touch
range fractionation
different cells have different thresholds for firing, over a range of stimulus intensities
Low -threshold neurons fire ____ than medium and high
easier
What is the threshold for a medium- threshold neuron
250
how many touch systems are there
4
True or False?
pain= really intense touch
false
Pain neurons are _____ to the surface of skin and _____ likely to become damaged
closer
more
What are the 4 touch systems in simple terms
pain
touch
vibration
stretch
Which touch systems are just under the skin
pain
touch
why are touch systems located just under the skin?
for fast feeling
Which touch systems are located deeper under the skin?
vibration stretch
Does vibration have spatial localization?
no
True or False?
You map out the world with vibration in the same way you do with touch
false
how many touch receptors are there
5
Pacinian corpuscle
vibration
ruffini’s ending
stretch
merkel’s disc
touch
Meissner’s corpuscle
touch
Which touch systems are more precise
touch
Free nerve endings detect _____ and _____
pain
temperature
temperature receptors use the _____ pathway
pain
Aδ fibers represent _____ pain
first
_____ fibers are used in emergencies to warn you
Aδ
Are Aδ or C fibers more valuable?
Aδ
C fibers represent _____ pain
second
are Aδ myelinated
yes
are C fibers myelinated?
no
What are the two types of skin fibers used by pain
Aδ fibers
C fibers
C fibers are (large/small)
small
Aδ fibers are (large/small)
large
C fibers are for (sharp/dull) pain
Aδ fibers are for (sharp/dull) pain
dull
sharp
Are cold and hot temperature receptors the same or different?
different
True or False?
Pain and temperature are the same
true
_____ is the spice of life
TRPV
neurotoxin in chilies that activates C fibers
Capscaicin
How does Capsaicin activate C fibers
TRVP1
Capsaicin (kills/produces) neurons
kills
Capsaicin _____ body fat
melts
Capsaicin ______ atherosclerosis
slows
Capsaicin _____ blood pressure
lowers
Capsaicin _____ diabetes
fights
Capsaicin _____ body weight
lowers
Spicy food is (good/bad) for you
good
Hottest Indian curry
Phaal curry
True or False?
Capsaicin is sold in stores
true
what disease uses capsaicin
diabetes
Why do diabetics use capsaicin
speeds up neuronal death which reduces pain
Why is Capsaicin banned in equestrian sports
hypersensitive horses are more motivated to jump hurdles
In what individuals is vibration perception inportant?
blind
The body has two _____ touch systems
parallel
What are the two parallel touch systems
tonic receptors
phasic receptors
Receptors with slow or no decline in action potential frequency
tonic receptors
Receptors that adapt quickly by decreased frequency
phasic receptors
True or False
Our sensory cortex uses the same organization as our touch systems
true
Which of the parallel touch systems tells you that you just touches something; gets your attention
phasic
the part of the world a sensory neuron responds to
receptive field
_____ neurons have receptive fields
all
Sensory neurons receptive fields differ in _____ and _____
size
shape
Neurons on fingers have _____ receptive fields than those on less important areas for touch
smaller
Receptive fields on fingers _____ overlap
don’t
larger receptive fields _____ overlap
do
True or False?
Kids put things in their mouths to map them out because the mouth has smaller receptive fields than fingers
true
test that assesses a person’s ability to distinguish between two separate points of touch
Two-point discrimination test
What does the two point discrimination test measure
density of sensory receptors
touching the center of a receptive field results in _____ firing
maximal
Touching surrounding areas of a receptive field results in _____ firing
decreased
What does touching far away from a receptive field result in?
no effect on firing
Most sensory pathways pass through the ____ to end in the sensory cortex
thalamus
What are the two touch/pain pathways
dorsal column
spinothalamic
Which touch/pain pathway goes from spine to thalamus
spinothalamic
Which touch/pain pathway is for touch and vibration
dorsal column
Which touch/pain pathway is for pain and temperature
Spinothalamus
Homunculus
somatosensory cortex
A _____ _____ represents the innervation of a body region
cortical map
What is significant about the genitalia on the cortical map
sensitive but small area because not used to explore world
Humans have large regions of the cortical map donated to the _____ and _____
face
fingertips
the somatosensory cortex _____ after hand amputation
reorganizes
neuropharmacology is _____ based on treating pain
largely
What do free nerve endings have specialized receptors to respond to?
temperature change
chemicals
tissue injury
what a substance P
a pain neurotransmitter
What is the benefit of pain
tells you to stop doing something to stop tissue damage
Inherited mutated sodium channel in pain fibers in dorsal root ganglia
congenital insensitivity to pain
What did the man on fire have
Congenital insensitivity to pain
What do babies who chew fingers off have
congenital insensitivity to pain
What area is significant to congenital insensitivity to pain
dorsal root ganglia
What was the man on fire syndrome
hypersensitive pain receptors
skin blotches when feels something hot
patient feels like they’re on fire
_____ level of pain during everyday tasks tells us when a certain movement or prolonged posture is harmful
low
During sleep, mild pain makes us toss/turn to prevent ______
bedsores
Canadian woman was born with _____ _____
pain insensitivity
What happened to the Canadian woman with pain insensitivity
Died at 28
_____ system transmits pain/temperature
spinothalamic
_____ _____ in the midbrain is involved in pain perception; opioid receptors
periaqueductal gray
Where emotions and pain come together
cingulate cortex
where is the periaqueductal gray
around the aqueduct
aqueduct
lake of spinal fluid
high emotions _____ pain
reduce
Where can pain be blocked?
In the spinal cord.
What theory explains spinal pain blocking?
Gate Control Theory of Pain.
How can the pain gate be closed?
By increased activity in A fibers.
What do A-beta fibers signal?
Touch sensation.
What non-physical factors can influence the pain gate?
Attention, emotions, and cognition.
How is pain blocked in the spinal cord?
By gating mechanisms.
What is TENS?
A method that delivers electrical pulses to the skin.
How does TENS reduce pain?
It activates A-beta fibers to close the pain gate.
What theory explains how TENS works?
Gate Control Theory of Pain.
Where does TENS stimulation ultimately send signals?
to the brain
non-drug treatments for pain
meditation/prayer
acupuncture
massage
physical activity
Chronic pain persists ____ after an injury has healed
long
True or False?
In chronic pain, the pain and disability can worsen over time
true
Which age group and gender is mostly affected by chronic pain
young women
What is another name for Reflex Sympathetic Dystrophy?
Neurogenic pain.
What happens in Stage I of RSD?
Severe localized pain, skin sensitivity, and swelling.
How long does Stage I of RSD usually last?
A few weeks.
What happens in Stage II of RSD?
Pain worsens and spreads; swelling increases.
What physical changes occur in Stage II of RSD?
Brittle hair/nails and muscle wasting.
What type of cycle is involved in RSD?
A vicious cycle of chronic pain.
What fuels the vicious pain cycle in RSD?
Persistent pain leads to overactivity in pain pathways and inflammation.
How does the nervous system contribute to the RSD cycle?
It becomes hypersensitive, amplifying pain signals.
What breaks the cycle of neurogenic pain?
Early treatment and nerve pathway modulation (e.g., physical therapy, medications, TENS).
What causes neurogenic pain?
Inappropriate signaling of pain by neurons.
What do spinal cord neurons take up during pain?
Substance P.
What effect does substance P have on spinal neurons?
It causes dendritic remodeling.
What happens to light touch input in neurogenic pain?
It activates hyperexcitable pain pathways.
What change occurs in GABA neurons during chronic pain?
They switch from inhibitory to excitatory.
What does chronic pain do to the spinal cord?
It remodels connections between neurons.
What happens to red and blue neurons in chronic pain?
They become cross-linked, misrouting sensory input.
True or False?
Chronic pain remodels sensory cortex
true
Patients in chronic pain have _____ somatosensory cortex, even at _____
overactive
rest
Where does pain become emotional?
In the anterior cingulate cortex (ACC).
What happens in the ACC as pain unpleasantness increases?
ACC activity increases.
Does pain unpleasantness increase activity in the somatosensory cortex?
No, only in the ACC.
What areas are activated by painful heat?
Somatosensory cortex and ACC.
What did Tito have?
Sensory integration disorder
What is Sensory Integration Disorder?
Difficulty processing and responding to sensory input.
What is hypersensitivity to touch?
Overreaction to tactile input; avoids touch.
What are signs of hypersensitivity?
Hates grooming, picky with textures, avoids barefoot walking.
What is hyposensitivity to touch?
Underreaction to touch; seeks tactile input.
What are signs of hyposensitivity?
Craves touch, rough play, self-harming behaviors.
What is synesthesia?
A stimulus in one sense creates a sensation in another.
What does synesthesia involve in the brain?
Mixing of inputs in association areas.
What’s an example of synesthesia?
“This food tastes blue” – taste triggering color perception.
Name some types of synesthesia.
Music-color, grapheme-color, taste-shape, sound-taste.
What can cause synesthesia?
LSD, seizures, sensory loss, or it may occur spontaneously.
What is “DIY synesthesia”?
Induced synesthetic experiences through drugs or altered states.
What causes DIY synesthesia?
Psychedelic hyperconnectivity in the brain.
What does psychedelic hyperconnectivity do?
Increases cross-talk between brain regions, blending senses.
What is phantom limb pain?
Pain felt in a limb that is no longer there.
What does Melville’s Moby Dick illustrate about phantom limbs?
That the limb is gone to the eye, but still felt by the “soul”—a vivid description of phantom sensation.
How does the brain create phantom limb pain?
The brain’s map of the body (somatosensory cortex) still includes the missing limb.
What sensation does a phantom limb often produce?
Tingling, itching, or pain in the missing limb.
