Physiology of pain Flashcards
What is the excitatory neurotransmitter released at the first order neurone synapse in substantia gelatinossa ?
Glutamate that binds to AMPA receptors of the second order neurons.
What is the phenomenon of wind up?
It is the frequency dependent increase in the excitability of the C fibers of the spinal cord to nociceptive stimuli. It is mediated through NMDA receptors.
How does ketamine produce analgesia ?
By inhibiting the wind-up phenomenon mediated by the NMDA receptor activation at the substantia gelatinosa.
How does TCA modulate chronic pain?
The TCA modulate descending noradrenergic pathway from the Locus cerulieus thereby reduce pain.
What is the principle receptor for mediating noxious heat and casacian like substance induced pain ?
TRPV-1 or Vanilloid agonist channels.
what is the origin of Morphine ?
It is extracted from the opium juice of the papaver somniferum plant.
what is the endogenous ligand for opioid receptor Mu in the brain ?
Enkephalin which belongs to the opioid peptide family of endorphins.
what is the main receptor for supraspinal analgesia ?
Mu
What are the receptors for spinal analgesia ?
Mu, K, delta and Nocieptin receptor.
What are the receptors for peripheral analgesia ?
Mu and Kapa
Opioid receptor for respiratory depression , physical dependence, and euphoria ?
Mu.
Opioid receptor for pupillary constriction and sedation
Mu and kappa.
What is the opioid receptor responsible for catatonia ?
Nociceptin receptor.
What is the effect of supraspinal nocieptin receptor activation ?
Anti-opioid effect.
what is the mechanism of opioid induced respiratory depression?
The activation of Mu receptors at the pre-Bötzinger complex, which controls inspiratory drive, and the Kölliker-fuse and lateral parabrachial nuclei, which control upper airway coordination and termination of inspiration causes reduction in RR and sensitivity of these centres to hypercapnia.
