Pain

Question 1

Where is motor and touch information sent to?

Answer 1

Mid brain

Question 2

Where is pain information from?

Answer 2

Around spinal cord

Question 3

What is nociception?

Answer 3

Sensing a stimulus that evokes pain

Question 4

Pain can be chemical, mechanical or thermal. What is the difference between pin prick pain and deep/true pain?

Answer 4

Deep pain is more extreme

Question 5

What causes ion channels to open when experiencing chemical, mechanical and thermal pin prick pain?

Answer 5

Chemical - ion channels open with chemicals
Mechanical - ion channels open with movement
Thermal - temperatures activate distinct thermal nociceptors

Question 6

pain is usually detected by what part of a nerve?

Answer 6

Free nerve endings

Question 7

What are transient receptor potential channels

Answer 7

Ion channels that are activated by inflammation, injury, molecules found in spices or cooling agents, pressure, stretch etc

Question 8

Give an example of a molecule found in spice that activate transient receptor potential channels (TRPs)

Answer 8

Capsaicin

Question 9

Give an example of a cooling agent that activates transient receptor potential channels

Answer 9

Menthol

Question 10

What are the 4 main types of nerve fibres?

Answer 10

A alpha
A beta
A delta
C fibres

Question 11

Which are the fastest and slowest nerve fibres?

Answer 11

A alpha fastest

C fibres slowest

Question 12

Why are C-fibres slowest?

Answer 12

Unmyelinated - cannot do saltatory conduction

Question 13

Grey matter has layers. What are these called, how many are there?

Answer 13

Laminae

I to X

Question 14

What is the second layer/lamina of grey matter called?

Answer 14

Substantia gelatinosa

Question 15

What is in lamina II?

Answer 15

Substance p - acts as neurotransmitter

Question 16

What is the receptor to substance P

Answer 16

NK1 (neurokinin 1)

Question 17

What are the types of ascending pain pathways?

Answer 17

Ventrolateral (includes spinothalamic and spinoreticular)

Spinocervicular

Question 18

Where does the spinothalamic tract go? What stimuli does it detect?

Answer 18

Spine to thalamus

Detects pinprick and thermal stimuli

Question 19

Where does the spinoreticular tract go? What stimuli does it detect?

Answer 19

Spine to reticular formation

True pain

Question 20

Where does the spinocervicular tract go? Which species does not have this tract?

Answer 20

From thalamus sub nuclei, through cerebellum through medial meniscus, lateral cervical nucleus
Humans

Question 21

What activates the vomiting centre?

Answer 21

Pain
Vestibular apparatus
Chemoreceptor trigger zone

Question 22

What are the exceptions to the rule that pain = nociception?

Answer 22

Phantom limbs
Pain gate
Referred pain
Hyperalgesia

Question 23

What is the pain gate?

Answer 23

Certain stimuli (e.g. stress) can switch off the ascending signal and cannot reach the CNS

Question 24

What is referred pain?

Answer 24

Pain is felt in different place to actual injury

Question 25

What are the 2 causes of referred pain?

Answer 25

Ascending fibres packed so close together that brain cannot distinguish the source
Several nociceptive fibres synapse on the same ascending fibre

Question 26

What causes phantom limb pain?

Answer 26

Nociceptive fibres synapse on same ascending fibre

Also denervated fibres can re-innervate other tissues

Question 27

What causes hyperalgesia?

Answer 27

Local inflammation

Spinal cord re-wiring

Question 28

What can be used in research to asses pain threshold?

Answer 28

Von Frey Hairs