Physiology of Pain

Question 1

What are the sites of action of opioid analgesia effects?

Answer 1

inhibition of ascending pain pathways and/or activation of descending inhibitory pathways

Question 2

Define: Opioid

Answer 2

refers to a compound with pharmacology similar to morphine

Question 3

Define: Analgesic

Answer 3

pain-relieving, includes other drugs that are not opioids as well

Question 4

Describe the Opioid receptor signaling mechanism

Answer 4

opioid effects are inhibitory, activation of the receptor will= inhibit cAMP production, inhibit certain Ca+ channels, activate K+ channels. the response of the neuron includes decreased neuronal firing and inhibited transmitter release

Question 5

What are the effects of stimulation of Mu receptors?

Answer 5

analgesia, anesthesia, sedation, respiratory depression, emeis, decreased gastrointestinal motility, euphoria and dependence, miosis

Question 6

What are the effects of stimulation of Kappa receptors?

Answer 6

analgesia, dysphoria, sedation

Question 7

What are the effects of stimulation of Delta receptors?

Answer 7

analgesia

Question 8

Where are Mu receptors located?

Answer 8

-periaqueductal gray= pain perception
-nucleus accumbens and ventral tegmentum area= reward
-brain stem= respiratory depression
-peripheral terminals and dorsal horn= transmission of painful stimuli
-small intestine= decreased gastrointestinal motility