• Somatosensation
• Blog #2 deadline moved to Friday

• Internal (interoceptive)
  • Where am I? How do I feel?
  • Proprioception
• External (exteroceptive)
  • What’s in the world?
  • Where is it?

• Vestibular sense
  • Head position (relative to gravity)
  • Head movement (rotation, translation)

• Kinesthesia
  • Body position
  • Movement
• Pain

• Cutaneous senses (touch)
  • Hot, cold
  • Pressure
  • Vibration
  • Damage (pain)
• Plus kinesthesia (why?)

• Why are spicy foods hot?
• Why are minty foods cool?

• Menthol/mint receptor (CMR1)
  • Also signals "cool"
• Vanilloid Receptors (VR1, VRL1)
  • Also signal "hot
  • Capsaicin

• Cutaneous receptors
• Dorsal root ganglion
• Ventral posterior lateral thalamus
• Primary somatosensory cortex (S1)
  • Parietal lobe

• Dorsal column/medial leminiscal pathway
  • Touch, proprioception
• Spinothalamic tract
  • Pain, temperature

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• Perceiving Where
  • Somatotopic maps – where on skin
  • Kinesthesia – configuration of limbs
• Perceiving What
  • Patterns of smoothness, roughness, shape, temperature

• The "real" reason for brains