Week 3 - Acute Pain

Question 1

What is the pain pathway?

Answer 1

• Pain signals carried by, A-delta fibres
  - myelinated = fast
  - initial sharp pain
• C fibre follows
  - non myelinated = slow
  - dull, throbbing pain that follows
• signals travel through peripheral nerve
• neurone - dorsal horn spinal cord (normally send the message up the tract to the thalamus)
• interneurons (secondary neurons)
  - synapse dorsal horn neurone
  - augment pain signal - ramp it up
  - inhibit pain signal
  - “gate-control” action (flood area with other messages, shaking finger around after slamming in door, to gate the pain signals
• travel up spinal cord to thalamus
• thalamus sends signals out to several brain regions
  - control touch
  - emotion
  - physical reaction
  - memory
• then sensory cortex
  - postcentral gyrus (location)
  - lateral parietal lobe (broader location)
  - brain decides what to feel = ‘pain’

Question 2

True or false, the amount of pain experienced is a good match for the amount of injury in the tissues

Answer 2

False