Test 3 - 10/2 Lecture Flashcards
The main difference in myelination status in the fast pain and slow pain pathways is the myelination of the
First order nociceptor
The cell body on the nociceptor is located in the ______
Dorsal root ganglia
Fast pain uses _____ neurotransmitters. Slow pain uses _____, ______ and ______ neurotransmitters.
Glutamate.
Glutamate, substance P, and CGRP.
T/F. All slow pain is stopped before it makes it to the parietal lobe
False. A small amount can make it to the parietal lobe
Where does lateral inhibition take place?
In the cord but also some happens in the periphery
Neurotransmitter release is mediated via what?
AP causes Calcium entry into the presynaptic cell
The second order neuron of the spinothalamic tracts may or may not be ______ regardless of if it synapses with the fast or slow pain primary neuron
myelinated
Are second order neurons myelinated?
Most of them are myelinated
Where does the cell body for the 3rd order neuron sit? what about the rest of the cell?
cell body is just outside dorsal horn and then a penetrating portion goes into dorsal horn for synapse
Describe the myelination of the grey matter in regards to fast pain
Fast pain is all myelinated. Grey matter is typically only cell bodies and non myelinated but a small portion can be myelinated (ex fast pain pathways
Metabotropic glutamate receptors are typically found _____
“more upstairs” more in the brain
Glutamate Ionotropic and metabotropic receptors tend to be ________
excitatory in nature
an opiate Mu receptor is synonymous with
Enkephalin receptors
What type of receptor is an enkephalin receptor
a GPCR with a 7TM spanning domain.
When Enkephalin receptors are activated the action that is carried out by it’s activated alpha sub-unit is _______
opening potassium channels allowing K out of cell; causing hyperpolarization hence the pain control (bc they are more difficult to excite)
How do opiate receptors work?
They increase cell wall permeability to potassium and that inhibits the cells.
Alpha-2 receptors in the pain pathways have what function when activated?
They increase cell wall permeability to potassium and that inhibits the cells.
Alpha 2 activation at the synapse will have what affect?
It will shut down the first order nociceptor and the second order pain transmission neuron
3 examples of alpha 2 agonist from lecture ranked in order of lease selective for alpha 2 to most selective to alpha 2
1- Xylazine
2- Clonidine
3- Precedex (most selective)
Which medication mentioned (Xylazine, clonidine, precedex) works on both alpha 1 and 2?
Xylazine
Zylazine, clonidine and precedex have what affect?
pain suppression and relaxation. Doesn’t work upstairs (no euphoria)
Horse tranquilizer mentioned in class
Xylazine
One way volatile anesthetics cause inhibition in the nervous system is by
Generalized increase in potassium conductance causing pain suppression/hyperpolarization
For our class potassium will always be ______ the cell and that will cause _____
Leaving.
Hyperpolarization
We can expect an increase in cyclooxygenase II in the spinothalamic tract in response to _______
Frequent activation/pain
COX 2 is expressed within our ______
first order and second order pain neurons
An increase in COX II would also cause an increase in
Prostaglandins
Prostaglandins that are produced from an increase in COX 2 will act on ______ receptors located on ______ and cause ______
Prostaglandin.
1st order and 2nd order ascending pain transmission neurons.
Increased sensitivity to painful stimuli.
What do prostaglandins have to do with action potential?
They don’t directly cause an AP but will increase the chances of an AP or repetitive AP
i NOs is ______ and causes ________ in regards to pain.
an inducible form of Nitric Oxide Synthase; an increased sensitivity to pain.
How do we typically think of iNOs? (not in regards to pain)
relax blood vessels and keep BP down and gives us organ perfusion.
3 examples of substances that increase sensitivity to pain without exciting the cells themselves
1- Prostaglandins
2- COX 2
3- i NOs
We may recommend a _______ supplement to someone with chronic pain. Why?
Magnesium; it is thought that it inhibits the NDMA receptors.
What can happen if you take too much mag?
runnnnnnnin to da bathroom
Does Ca as a supplement help with pain? what does Ca help with?
No. Ca does help settle down nervous system but increased extracellular calcium doesn’t help with pain
List the 4 spinal reflex pathways
1- Stretch Reflex
2- Tendon Reflex
3- Withdrawal Reflex
4- Crossed Extensor Reflex
2 Reflexes that are a response to pain
1- Withdrawal Reflex
2- Crossed Extensor Reflex
2 reflexes that are tension/stretch reflexes
Stretch reflex
Tendon reflex
A spinal cord reflex can be elicited by _____ or _______
pain or tension receptors in our skeletal muscles/tendons
How does direct communication work with sensory and motor neurons?
If there is a strong enough signal the Sensory neuron will go into dorsal horn and up to the anterior horn and the neurotransmitter release can activate the motor neuron
What are the two ways the sensory and motor neurons can talk?
Direct communication
via intermediary (aka interneurons)
Are interneurons inhibitory or excitatory?
both excitatory and inhibitory