Touch Pressure

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TouchPressure Pain
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Touch

• Touch receptors are on the skin
• Skin is the largest heaviest organ (20 sq. ft.
  6 lbs.)
• Four basic skin senses are
• Pain, warmth, cold, and pressure
• All skin sensations are a combination of these
  four basic senses

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Pressure

• Only pressure has identifiable neural receptors
  Pacinian Corpusle located beneath the skin, it
  converts pressure stimulation into neural
  messages it sends to the brain.
• Constant pressure causes sensory adaptation and
  it either reduces the number of signals or quits
  sending them all together. (like the clothes on
  your body)
• Itch is caused by "itch-sensitive" neurons that
  respond to histamines.
• Sensory receptors are located unevenly on the
  body so certain areas are more sensitive than
  others.

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Temperature

• Temperature is sensed by specific spots that
  produce either cold or warm sensations.
• Cold spots can be triggered by cold or a hot
  stimulus.
• Warm spots only respond to warm stimulus of about
  105 degree Fahrenheit.
• If both warm and cold spots are stimulated at the
  same time you will feel hot.
• Various combinations of skin sensations produce
  different results
• Check out the Amazing Hypothermia Man (2 min)

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Cold Warm Receptors HOT!!!
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What purpose does pain serve?

• Pain is your bodys way of telling you something
  is wrong. It tells you to change your behavior
  immediately.
• Any external stimulus that can produce tissue
  damage can cause pain.
• Internal stimuli like disease or infection can
  also cause pain.
• Certain areas of the body are more sensitive than
  others

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Gate-control Theory of Pain

• Pain messages travel on one set of nerve fibers
  containing pain gates.
• The gates are open when pain is felt.
• Other sensory messages go through another set of
  fibers.
• The nonpain fibers can close the pain gates to
  stop the sense of pain.

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The Process of Gate-Control Theory

• Intense stimulus activates small-diameter sensory
  fibers called free nerve endings.
• Free nerve endings carry their messages to the
  spinal cord, releasing a neurotransmitter called
  substance P that activates other neurons to send
  their messages through the open spinal gates to
  the thalamus.
• Thalamus sends pain signals to frontal lobes and
  limbic system.
• Brain interprets pain and sends messages to the
  spinal cord to either close or open gates. If
  more gates open, pain gets worse. If gates
  close, less pain experienced.
• Endorphins can be released which inhibit the
  release of substance P thus lessening pain.
• Muscle Tension, psychological arousal and rapid
  heart beat can all produce or intensify pain.

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The Pain Process
2. Free Nerve Endings (located in skin, muscles,
internal organs)
Carries Message To
Activates
3. Spinal Cord (which releases substance P)
1. Intense Stimulus
causes
Closes the Gates
Pain is reduced
4. Other Neurons to activate send pain message
to the Thalamus through open Spinal Gates. Brain
then
Leaves Gates Open
Pain is intensified
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Biopsychosocial Perspective

• Our experience of pain is much more than neural
  messages sent to the brain.

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Can we distract ourselves from the pain? YES!

• An athlete who is injured doesnt realize it
  until after the game.
• Emotions and cultural differences can influence
  the brain's decisions on opening or closing
  gates.
• Person's mental state can influence one's
  experience of pain.
• Distraction focus on a nonpainful stimulus
• Imagery create a vivid mental image can help
  control pain.
• Positive Self Talk "It hurts, but I'm OK." Or
  redefine pain.
• Counter irritation create a strong competing
  sensations that's mildly stimulating or
  irritating. Rubbing a sore area. Stimulating
  the gate-closing nerve fibers can help lessen
  pain. Rubbing a stubbed toe creates a competing
  stimulation that will block some of the pain
  messages. Putting ice on a bruise sends cold
  messages to the brain which lessen the pain
  messages.
• Relaxation Deep breaths and relaxing deeply

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An Acupuncturist's Nightmare

• Watch Video Clip

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Virtual Reality Pain Control

• For burn victims undergoing painful skin repair,
  an illusory virtual reality can powerfully
  distract attention, thus reducing pain and the
  brain's response to painful stimulation

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Virtual Reality Distracts the Brain

• The burn victims brain is less responsive to
  painful stimulation, as shown by these MRI scans

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Pain and Phantom Pain

• The brain comes prepared to anticipate that it
  will be getting information from the limbs of the
  body. This is why amputees may experience
  sensations in a phantom limb.
• Phantom limb sensations the brain is
  misinterpreting central nervous system activity
  that occurs in absence of the normal sensory
  input from that limb. This can be true of the
  other senses as well.
• Play Phantom Limb Pain Fooling the Mind (429)
  Segment 20 from The Mind Psychology Teaching
  Modules (2nd edition).