Pain and Thermosensation

Question 1

Most analgesics that are normally used to treat pain have limited use in pathological pain, however what are some options?

Answer 1

Atypical analgesics e.g. antidepressants, anticonvulsants and local anaesthetics

Question 2

Nociceptors are usually activated by what?

Answer 2

Intense stimuli (thermal, mechanical or chemical) that are noxious

Question 3

What order neurones are nociceptors?

Answer 3

First order

Question 4

Pain is only felt when?

Answer 4

Once nociceptors have passed on their information to the CNS

Question 5

Nociceptors are what type of neurones? They have what type of nerve ending?

Answer 5

Pseudounipolar / free nerve endings

Question 6

Complete the sentence: nociceptive input causes ? of the free nerve ending which produces an ? which progresses along the soma of the neurone and causes the release of ?

Answer 6

Depolarisation / action potential / neurotransmitter

Question 7

Activation of the first order neurone (nociceptor) should only respond to intense, noxious stimuli. What happens if these are activated without stimuli?

Answer 7

Hyperalgesia/allodynia

Question 8

What type of nerve fibres are nociceptors?

Answer 8

A delta and C

Question 9

What are the different types of stimuli that can activate the peripheral terminal of polymodal nociceptors?

Answer 9

Chemical, mechanical and thermal

Question 10

The soma of the first order neurone (nociceptor) is found where?

Answer 10

Either in the dorsal root ganglion or the trigeminal ganglion

Question 11

What happens when fibres from a nociceptor reach the dorsal horn of the spinal cord?

Answer 11

They synapse and cross over

Question 12

After a nociceptor synapses with its second order neurone in the spinal cord, the axon of the second order neurone then carries the information up which spinal cord tracts to the CNS?

Answer 12

Spinothalamic and spinoreticulothalamic

Question 13

Peptidergic polymodal nociceptors are a subset of which type of nociceptor fibre?

Answer 13

C-fibres

Question 14

Complete the sentence: afferent aspects of nociceptors transmit nociceptive information to the CNS via the release of ? and ?, within the ? horn of the spinal cord

Answer 14

Glutamate and peptides / dorsal

Question 15

Describe visceral pain?

Answer 15

Tends to be poorly localised and have a dull, aching character

Question 16

The brain interprets nociceptive information arising from the viscera as originating from an area of skin that may be distant to the internal organ. What is this known as?

Answer 16

Referred pain

Question 17

Visceral pain that is perceived at a distant site from the affected organ is often associated with what features?

Answer 17

Nausea, vomiting, sweating and pallor

Question 18

Referred pain around the umbilicus can come from where?

Answer 18

Appendix

Question 19

Referred pain around the epigastric region can come from where?

Answer 19

Stomach/pancreas

Question 20

Referred pain down the arm and in the jaw can come from where?

Answer 20

Heart

Question 21

Referred pain to the shoulders can come from where?

Answer 21

Liver/diaphragm/gallbladder

Question 22

Viscerosomatic pain is usually sharp and well localised - what causes this?

Answer 22

When inflammatory exudate from a diseased organ contacts a somatic structure

Question 23

Pain evoked by activity in nociceptors can be reduced by simultaneous activity in where?

Answer 23

Low threshold mechanoreceptors (A beta fibres)