Introduction to Pain

Question 1

How is pain sensed?

Answer 1

Nociceptors can respond to stimuli over a certain threshold which gives the feeling of pain

Question 2

What are the 3 fibres types, function and marker?

Answer 2

Alpha beta - touch - neurofilament
Alpha gamma - fast pain - neurofilament
C - slow pain - IB4 or neuroepetides

Question 3

What are the 2 ascending pathways and their purpose?

Answer 3

Spinothalamic - discriminative aspect of nociception. fast pain
Spinoreticular - responsible for arousal and affective aspects (dull pain)

Question 4

What are opiods?

Answer 4

when they reach opioid receptors and they can relieve pain

Question 5

What are the PAG and RVM in descending pain modulatory system?

Answer 5

PAG = periaqueductal gray - rich in opioid receptors
RVM = rostral ventromedial medulla - allows inhibition and facilitation of nociceptive processing

Question 6

What factors affect the pain gate?

Answer 6

Amount of activity in pain fibres
amount of activity in other peripheral fibres
messages descending from the brain