ML3 Nociception

Question 1

How are free nerve endings classified

Answer 1

classified according to the properties of the axon not the nerve ending

Question 2

Three classes of nociceptors (& associated fibres)

Answer 2

Polymodal (C fibres)
Að mechanosensitive
Að mechanothermal

Question 3

What are TRP channels

Answer 3

Transient receptor potential channels

• structurally similar to voltage-gated K+ channels or cyclic nucleotide-gated channels
• six TM domains with a pore between 5 and 6
• respond to dif levels of heat/cold
  e. g. VR-1 and VLR-1

Question 4

Two components of the central pain pathway

Answer 4

1. Sensory discriminative

2. Affective motivational

Question 5

What does the sensory discriminative component detect?

Answer 5

• location
• intensity
• quality

Question 6

Where does the sensory discriminative component relay to?

Answer 6

Primary SS cortex

Question 7

What does the affective motivational component do?

Answer 7

• signals the unpleasant quality

- enables fight or flight

Question 8

Where does the affective motivational component relay to?

Answer 8

Cortex and brainstem

Question 9

What is dissociated sensory loss?

Answer 9

Unilateral lesion will result in
loss of ipsilateral mechanosensory perception
loss of contralateral pain perception