Pain

• What is the difference between 1st & 2nd pain?

  1st pain

  • fast
  • due to heavily myelinated A delta fibres

  2nd pain

  • slow
  • ache
  • due to non-myelinated C fibres

  
• A-delta & C nociceptors have different patterns of projection into the dorsal horn.

  1 neuron can project to multiple targets.
• Nociception - body


  Nociceptive signals travel through dorsal horn -> decussates immediately -> neurons project via anterolateral system through spinothalamic tract -> up to thalamus (ventral posterior lateral nucleus) -> thalamocortical neurons project to somatosensory cortex 

  
• Nociception - face


  Nociceptive signals travel from trigeminal system -> decussate -> to ventral posterior medial nucleus of the thalamus -> thalamocortical neurons project to somatosensory cortex

  
• It is possible to influence the way that you experience pain -> cortex can control pain.

  Can be conscious (detemination) & unconscious (distraction)