L111: Pain and Nociception

Question 1

What type of nerve fibres perceive ‘normal’ pain?

Answer 1

• Aδ. (dull and aching);
• C-fibres (dull, slow-acting).

(both afferent nerves)

Question 2

What type of nerve fibres perceive ‘sharp’ pains?

Answer 2

Aα and β

Question 3

What factors perceive pain?

Answer 3

• Genetic;
• Molecular;
• Cellular;
• Anatomical;
• Physiological;
• Psychological;
• Social.

Question 4

How is pain modulated at a segmental level?

Answer 4

• Stimulation of other nerve fibres (e.g. Aβ), by rubbing/ touch;
• Large branch (new stimulus, Aβ) goes to the sensory cortex (brain);
• Small branch (initial stimulus) goes into the dorsal horn and inhibits;
• Blocks second order pain.