Pharmacology of Pain N28

Question 1

Pain can be described as

Answer 1

physiological sensation, emotional and physiological reaction to painful stimuli

Question 2

Pathway of pain

Answer 2

nociceptors –> substantia gelatinosa (modulated by enkephalins of descending tracts) –> STT –> thalamus–> cerebral cortex, limbic system, sensory cortex

Question 3

Perception of pain involves

Answer 3

reticular activating system (RAS), limbic system, sensory cortex

Question 4

Autocoids

Answer 4

bradykinin, histamine, prostaglandins, leukotrienes released in response to irritation or tissue injury

Question 5

Autocoids action

Answer 5

stimulate nociceptors or increase their sensitivity

Question 6

Substance P

Answer 6

present in Type C fibers, key role in pain transmission

Question 7

Endorphin/Enkephalin

Answer 7

opioids, modulate processing of pain in the spinal cord, inhibit transmission of pain and Substance P

Question 8

Serotonin

Answer 8

Modulates processing of pain in the spinal cord and thalamus

Question 9

3 mechanisms of altering pain

Answer 9

reduce irritation and inflammation ( NSAIDS, aspirin), block conduction of impulses (anesthetics), modify the pain processing (opioids)

Question 10

NSAIDS, Aspirin, ibuprofen, ect action

Answer 10

Inhibit COX and the formation of prostaglandin which reduced inflammation; decrease sensitivity of nociceptors

Question 11

Local Anesthetics (Lidocaine, procaine)

Answer 11

block Na channels to prevent depolarization and conduction of pain signals; Type C are particularly effected, cause profound analgesia, useful in nerve blocks

Question 12

Opioids (morphine, herion, codeine, meperidine, hydromorphone)

Answer 12

Pain is still present, but it alters the psychic component or reaction to pain in the limbic system, ability to modulate processing of pain in CNS

Question 13

Endorphines, Dynorphins, and Enkephalins

Answer 13

endogenous opioids, act on limbic system and spinal cord, modulate pain pathways and the emotional response to pain

Question 14

4 types of opioid receptors

Answer 14

mu, kappa, delta, and sigma

Question 15

Mu receptors

Answer 15

Brainstem and limbic areas, mediate supraspinal analgesia, respiratory depression, euphoria, dependence

Question 16

Kappa receptors

Answer 16

brainstem and spinal cord, mediate spinal analgesia, meiosis, sedation, and dysphoria

Question 17

Delta receptors

Answer 17

brainstem and limbic system, mediate dysphoria and hallucinations

Question 18

Mophine acts as endophine/enkephalin _____

Answer 18

AGONISTS

Question 19

Naloxone (Narcan) acts as endorphin/enkephalin _______

Answer 19

ANTAGONISTS

Question 20

Role of endogenous opioids in STIMULUS-INDUCED analgesia

Answer 20

Opioid peptides increase due to stimulus, use of opioid antagonist suggest that the pain has been blocked by OPIOIDS only (returns with antagonists)

Question 21

Stimulus-induced analgesia may include

Answer 21

acupuncture, exercise, stress, drugs, electrical stimulation