Opiates Flashcards
The (δ/κ/μ) opioid receptor is less well defined than the others. It modulates both spinal and supraspinal analgesia while also exhibiting less capacity for dependence formation.
δ
The (δ/κ/μ) opioid receptor primarily deals with supraspinal analgesia. It also causes miosis, respiratory depression, euphoria, and development of dependence.
μ
The (δ/κ/μ) opioid receptor primarily modulates spinal analgesia. It may cause weak supraspinal analgesia, along with weak miosis, sedation, weak respiratory depression, and dysphoria.
κ
Opioid receptors are G-protein coupled receptors that span the membrane ___ times.
7 times
A(n) ______________ is an endogenous opioid that has the highest affinity for μ-receptors. It possesses decreased affinity for δ-receptors.
Endorphin
A(n) ______________ is an endogenous opioid that has the highest affinity for δ-receptors. It possesses decreased affinity for μ-receptors.
Enkephalin
A(n) ______________ is an endogenous opioid that has the highest affinity for κ-receptors. It possesses decreased affinity for both δ-receptors and μ-receptors.
Dynorphin
In the presynaptic terminal, μ-receptor activation (increases K+ conductance/decreases Ca2+ influx) in response to an incoming action potential.
Decreases Ca2+ influx
In the postsynaptic terminal, μ-receptor activation (increases K+ conductance/decreases Ca2+ influx) and thereby inhibits postsynaptic response to excitatory neurotransmission.
Increases K+ conductance
Analgesia caused by opioids is more effective against (dull/sharp) pain.
Dull
Stimulation of the μ-receptors (increases/decreases) the pain threshold while also (increasing/decreasing) the response to pain.
- Increase pain threshold
- Decrease response to pain
Analgesic effects modulated by the μ-receptors are primarily produced at the (spinal/supraspinal) level.
Supraspinal
Stimulation of the μ-receptor causes (increased/decreased) tone and (increased/decreased) motility in one’s GI tract.
- Increased tone
- Decreased motility
(T/F) Opioids acting at μ-receptors may be used as anti-diarrheals due to their constipative effects.
True.
Opioids that act at μ-receptors may cause miosis by activity at the ________________ nucleus.
Edinger-Westphal nucleus
After chronic opioid use, (little/substantial) tolerance is developed to the miosis-inducing effects of opioids.
Little tolerance
_______________ is the only opioid that does not cause miosis.
Meperidine