Opioids

Question 1

Tissue damage

Answer 1

Release of inflammatory chemicals (histamine, bradykinin -> prostaglandins, substance P which act as NTs that inhance movement of impulses across nerve synapses)

Question 2

Transduction

Answer 2

Energy of the stimulus is converted to electrical energy

Nocioceptor -> action potential

Question 3

Transmission

Answer 3

Dorsal horn of spinal cord, cross to opposite side, ascend to higher centers of the brain

This is usually where opioids interact

Question 4

Perception

Answer 4

Cerebral cortex interprets the signal, process information, perceives pain
Awareness of pain
Somatosensory cortex identifies the location/intensity
Associated cortex determines how an individual interprets its meaning

Question 5

Delta receptor (OP1)

Answer 5

Location: brain (pontine nuclei, amygdala, olfactory bulbs, deep cortex)
Function: ANALGESIA, antidepressant effects, physical dependence

Question 6

Kappa receptor (OP2)

Answer 6

Location: Brain (hypothalamus, periaqueductal gray, claustrum), spinal cord (substantia gelatinosa)
Function: Spinal analgesia, sedation, miosis, inhibition of ADH release, dysphoria

Question 7

Mu receptor (OP3)

Answer 7

Location: Brain (cortex, thalamus, striosomes, periaquaductal gray) Spinal cord (substantia gelatinosa) Intestinal tract
Function:
mu 1: supraspinal analgesia, physical dependence
mu2: respiratory depression, miosis, euphoria, reduced GI motility, physical dependence
mu3: ?

Question 8

Nociceptin receptor (OP4)

Answer 8

Location: Brain (cortex, amygdala, hippocampus, septai nuclei, habenula, hypothalamus) spinal cord
Function: anxiety, depression, appetite

Question 9

Pre-synaptic inhibition

Answer 9

Reduced intracellular cAMP, decrease Ca ion influx, inhibits the release of excitatory NT (glutamate, substance P)

Question 10

Post-synaptic inhibition

Answer 10

Hyperpolarization of the neuronal membrane which decreases generation of AP