MEDC0013 - Pain Test With Complete Solutions
gate control theory of pain - ANSWER that the spinal cord contains a neurological 'gate'
that either blocks pain signals or allows them to continue to the brain for pain to be
perceived
opiates - ANSWER opium and its derivatives, such as morphine and heroin; they depress
neural activity, temporarily lessening pain and anxiety
Which brain region is predominantly responsible for pain localisation and the emotional
experience? - ANSWER cortex
Explain how the feeling of pain arises following injury? - ANSWER 1. when the tissue is
damaged, chemical mediators are released
2. these chemical mediators depolarise the C-fibres
3. locally released prostaglandins sensitise the neurones to the action of these
mediators
4. at the central terminus in the dorsal horn of the spinal cord, the nociceptive fibres
release peptides
5. these activate the spinothalamic tract neurones that carry pain signals to the
contralateral thalamus
6.from the thalamus, pain signals pass to the cortex and other CNS regions to elicit the
conscious sensation of pain and the emotional response
How do opioids prevent pain? - ANSWER they inhibit transmission of pain in the dorsal
horn mainly by presynaptic inhibition of afferent impulses
How can we manage pain at the site of injury? How do they work? - ANSWER - NSAIDS
- COX inhibitors
they reduce the concentration of mediators such as bradykinin, prostaglandins, ATP
What do NSAIDs and COX inhibitors reduce - ANSWER concentration of mediators such
as bradykinin, prostaglandins, ATP
What are the 2 types of pain fibres? - ANSWER C-fibres
A-delta fibres
C fibres - ANSWER transmit the longer-lasting, duller pain that persists after the initial
injury
, A-delta fibers - ANSWER transmit the initial sharp pain one might feel right away from a
sudden injury
How can we block pain at the level of the C-fibre? How does this work? - ANSWER give
Na channel blockers stopping the signal being transported to the dorsal horn
dorsal horn - ANSWER a region at the rear of the spinal cord that receives inputs from
receptors in the skin
Which fibres are responsible for the non-painful stimulus in the gate control theory of
pain? - ANSWER A beta fibres
A-beta fibers - ANSWER touch and pressure
What are the 2 main categories of opioid drugs? - ANSWER 1. morphine and related
compounds such as heroine and codeine
2. synthetic analogues of morphine such as pethidine, methadone, buprenorphine
What are the side effects of opioids? - ANSWER - pain relief
- euphoria
- constipation
- cough supression
- pupil constriction
- vomitting
- itching
- respiratory depression
What are the 3 types of receptors opioids act on? - ANSWER - mu
- delta
- kappa
How do opioids cause respiratory depression? - ANSWER Normally there has to be a
buildup of CO2 for the brainstem to initiate a breath. Opioids decrease the brainstems
response to CO2, resulting in respiratory depression.
Why do addicts prefer heroine to morphine? - ANSWER heroin is more lipid soluble and
so it can pass the BBB faster causing a euphoric effect quicker
What was the initial function for morphine? - ANSWER used as an anti-cough medication
What compound similar to morphine was discovered after working on pig brains? -
ANSWER enkephalins
gate control theory of pain - ANSWER that the spinal cord contains a neurological 'gate'
that either blocks pain signals or allows them to continue to the brain for pain to be
perceived
opiates - ANSWER opium and its derivatives, such as morphine and heroin; they depress
neural activity, temporarily lessening pain and anxiety
Which brain region is predominantly responsible for pain localisation and the emotional
experience? - ANSWER cortex
Explain how the feeling of pain arises following injury? - ANSWER 1. when the tissue is
damaged, chemical mediators are released
2. these chemical mediators depolarise the C-fibres
3. locally released prostaglandins sensitise the neurones to the action of these
mediators
4. at the central terminus in the dorsal horn of the spinal cord, the nociceptive fibres
release peptides
5. these activate the spinothalamic tract neurones that carry pain signals to the
contralateral thalamus
6.from the thalamus, pain signals pass to the cortex and other CNS regions to elicit the
conscious sensation of pain and the emotional response
How do opioids prevent pain? - ANSWER they inhibit transmission of pain in the dorsal
horn mainly by presynaptic inhibition of afferent impulses
How can we manage pain at the site of injury? How do they work? - ANSWER - NSAIDS
- COX inhibitors
they reduce the concentration of mediators such as bradykinin, prostaglandins, ATP
What do NSAIDs and COX inhibitors reduce - ANSWER concentration of mediators such
as bradykinin, prostaglandins, ATP
What are the 2 types of pain fibres? - ANSWER C-fibres
A-delta fibres
C fibres - ANSWER transmit the longer-lasting, duller pain that persists after the initial
injury
, A-delta fibers - ANSWER transmit the initial sharp pain one might feel right away from a
sudden injury
How can we block pain at the level of the C-fibre? How does this work? - ANSWER give
Na channel blockers stopping the signal being transported to the dorsal horn
dorsal horn - ANSWER a region at the rear of the spinal cord that receives inputs from
receptors in the skin
Which fibres are responsible for the non-painful stimulus in the gate control theory of
pain? - ANSWER A beta fibres
A-beta fibers - ANSWER touch and pressure
What are the 2 main categories of opioid drugs? - ANSWER 1. morphine and related
compounds such as heroine and codeine
2. synthetic analogues of morphine such as pethidine, methadone, buprenorphine
What are the side effects of opioids? - ANSWER - pain relief
- euphoria
- constipation
- cough supression
- pupil constriction
- vomitting
- itching
- respiratory depression
What are the 3 types of receptors opioids act on? - ANSWER - mu
- delta
- kappa
How do opioids cause respiratory depression? - ANSWER Normally there has to be a
buildup of CO2 for the brainstem to initiate a breath. Opioids decrease the brainstems
response to CO2, resulting in respiratory depression.
Why do addicts prefer heroine to morphine? - ANSWER heroin is more lipid soluble and
so it can pass the BBB faster causing a euphoric effect quicker
What was the initial function for morphine? - ANSWER used as an anti-cough medication
What compound similar to morphine was discovered after working on pig brains? -
ANSWER enkephalins
