7.2 The Mechanical Senses

  1. Capsaicin
    • Chemical that causes neurons containing substance P to release it suddenly.
    • Directly stimulates pain receptors sensitive to moderate heat.
  2. Dermatone
    Area of skin connected to a particular spinal nerve.
  3. Endorphins
    Endogenous morphines, produced by the body and stimulates the same receptors as does morphine. Decrease pain.
  4. Gate Theory
    Spinal cord neurons that receive pain information also receive information from touch receptors and axons descending from the brain. They can inhibit pain signals.
  5. Opioid mechanisms
    Systems responsive to opioid drugs and similar chemicals such as endorphins.
  6. Pacinian corpuscle
    Touch receptor that responds to sudden displacement or high frequency vibration on the skin.
  7. Periaqueductal gray area
    Area of the midbrain where opiate receptors are found. Other than the spinal cord.
  8. Placebo
    • Drug or procedure with no pharmacological effect.
    • Reduces pain in patients by stimulating the cingulate cortex (emotion).
  9. Semicircular canals
    • Modified touch receptor.
    • Component of the vestibular system located near the cochlea. 
    • Oriented in perpendicular planes. Filled with a jellylike substance and lined with hair cells. Acceleration of the head is detected when movement causes the jelly to push against the hair cells.
  10. Somatosensory system
    • Sensory network that monitors the movement and sensations of the body.
    • Includes discriminative touch, deep pressure, cold, warmth, itch, pain, tickle, and the position and movement of joints.
  11. Substance P
    • Neurotransmitter released by nerves that are sensitive to pain.
    • Only released in addition to glutamate in the case of sharp pain.
Card Set
7.2 The Mechanical Senses
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