Exam 3 Flashcards
Where does the cord transmit information from the periphery?
-Brainstem
-Cerebellum
-Brain
What is an efferent pathway?
-The sending portion of the CNS (Motor primarily; travels down the cord)
What is an afferent pathway?
-Receiving portion of the cord (sensory; travels up the cord)
In the cord, sensory information is primarily transmitted in which general area?
-dorsal with some anterolateral
(Just in case he asks)
On the powerpoint slide regarding spinal cord, what color are the afferent vs efferent pathways? What do they mean?
-Afferent (receiving sensory) is blue; travels up the cord
-Efferent (sending primarily motor) is red; travels down the cord
What are some sensors for afferent sensory pathways mentioned in lecture?
-Temperature sensors in skin
-Vibration
-Pain
What type of matter is “decision making?”
Gray matter
What is located in gray matter?
-Cell bodies
-Lots of synapses
What is a tract?
A bundle of axons within the CNS
What is another name for a bundle of axons outside the PNS?
Nerves
What is another name for the main descending pathway?
Pyramidal Tract
What kind of actions can take place from the pyramidal tract, per lecture?
-Moving an arm around
-Moving a leg around
What is the Extrapyramidal Tract responsible for?
- Accessory motor pathways
-Coordinate complex tasks
-Help modulate, control, and give us feedback on instructions received from the pyramidal tract
Between the pyramidal tract and the extrapyramidal tract, which one is voluntary? Which one is involuntary?
Pyramidal tract - Primarily voluntary; aware of actions
Extrapyramidal tract - No realization or knowledge of functioning; helps fine tune motor commands
Where are the pyramidal tracts located? What are the names of the two pyramidal tracts? Which is bigger?
Lateral corticospinal tract - Posteriobilateral cord, superficial to the dorsal horn, deep to the outer edge of the cord where sensory information is; bigger
Anterior corticospinal tract - Also two areas immediately bilateral to the anterior median fissure
What are the four names of the sections within the extrapyramidal tracts?
-Rubrospinal tracts (4; immediately anterior to each lateral corticospinal tract)
-Reticulospinal tracts (2; deep anterior median fissure, bilateral to the start of the fissure)
-Olivospinal tract (2; lateral to Vestibulospinal tract)
-Vestibulospinal tract (2; lateral to the most anterior part of the anterior median fissure)
What is the main ascending (afferent pathway)?
The dorsal column pathway
What things do the Dorsal column pathways do as described in lecture?
-Pressure sensors in skin
-Are you holding anything in your hands?
-Are your hands in the air?
-Touch
-Perception
Which afferent pathway does pain follow?
The Anterolateral system
What are the two parts of the anterolateral system?
-Lateral spinothalamic tract (2; bilateral, immediately lateral to the Olivospinal tract)
-Anterior spinothalamic tract (2; bilateral; immediately deep to the Olivospinal tract)
What is another name for the anterolateral system?
-Spinothalamic tract/pathway
What path does the anterolateral system/spinothalamic tract follow?
-Pain enters cord and ascends via afferent pathway of the anterolateral system –> Pain relayed through the Thalamus –> Pain signal goes to parietal cortex to get sorted out (Where is the bad pain coming from; how severe is it?)
What is the collective name for the different parts of the gray matter of the cord?
-Rexed’s Laminae
-(Pronounced “rex-ed” or “rexed” per daddy Schmidt)
Where is lamina I located? What is another name for it?
-The most dorsal part of the dorsal horn.
-Lamina Marginalis
What is the Lamina Marginalis known for, and which # lamina is it?
-Sending fast pain signals to the brain
-Lamina I
Is lamina I myelinated? If so, what type of mylenation?
-Yes
-A-delta fibers (make sure to know what delta looks like in case he puts it on a test; can’t copy and paste; feel free to fix)
What is the path that fast pain takes to reach the final afferent pathway toward the brain?
Sensor –> Root –> Rootlet –> Cord –> Lamina I/laminate marginalis synapse cell bodies –> Crosses over via Lamina X –> Ascends in anterolateral cord
Collectively, lamina II & III are called
Substantia Gelatinosa
What goes through the Substantia Gelatinosa, and what lamina are they?
-Slow pain conduction
Lamina II & III
Are Lamina II & III myelinated?
-No
-Type C fibers (nonmyelinated)
Which lamina does the Substantia Gelatinosa synapse with sometimes in regards to slow pain?
Lamina V
What is the route that slow pain takes to reach the final ascending pathway?
Receptor –> Nerve –> Posterior Root –> Posterior rootlet –> Dorsal horn –> Lamina II & III; sometimes V –> Crossover through Lamina X –> Anterolateral spinothalamic pathway
What do laminae I-VI have in common?
Mechanoreceptors relay information to the gray matter in the cord
(Take physical pressure & turn it into electrical energy)
When Schmidt said we have quite a few mechanoreceptors, what two examples did he give in regard to location?
-Hands
-Skin
In the spinal cord, where is Lamina VI?
Directly lateral to the posterior portion of the lamina X crossover pathway
Which lamina group is sensory?
I-VI
Which lamina group is motor?
VII-IX
Which lamina is for crossover?
Lamina X
What are the two ways for the cell bodies in the anterior horn to be activated?
-Motor center in brain
-Reflex arcs
What is the white matter called that has crossover in the cord?
Anterior white commissure
What is another name for Lamina VII? Is it sensory or motor?
-Intermediolateral nucleus
-Motor
What is typical of Lamina VIII?
-Lots of large motor neurons
Both afferent and efferent signals can go through which two structures?
Anterior white commissure & Lamina X (grey)
Extrapyramidal tracts are
Primarily accessory motor pathways
Spinocerebellar tracts are
Sensory tracts that send information from the spinal cord to cerebellum
What is another name for the dorsal column pathway?
DCML (Dorsal-column medial lemniscal system
What signals do the DCML send? Where is it?
-Major pressure/sensory signals; major touch sensitive pathway
-Sits in the dorsal part of the cord
What structure does the dorsal column pathway pass through to get to the brainstem?
Medial lemniscal
What does the anterolateral/spinothalmic tract conduct?
Pain signals
What is another name for the pyramidal tract?
Corticospinal tract
What gives the corticospinal tract its name?
Signals originates in cerebral cortex & passes through the spine on the way to talk to the skeletal muscle
Is the corticospinal tract afferent or efferent? Where do the signal originate?
Efferent - originates in cerebral cortex/motor cortex
The DCML takes care or most kinds of signals except what?
Pain
What kind of nerve fibers are involved in the DCML pathway?
Type A fibers
What kind of A fibers does the DCML pathway have?
Alpha, beta, gamma, delta; varies - various sensations get sent through various fibers
Per Schmidt, what kind of sensations go through the DCML?
-Pressure
-Vibration
-“sensory stuff”
What part of the body does the left side of the CNS take care of?
Right; vice versa
Where does crossover occur in the DCML pathway? What is the path?
-Medulla
Sensation –> Posterior rootlet –> Cord –> Some sensation stays within gray matter; others go to the DCML to go to the medulla/brain
Why does some sensory information stay in the gray matter in the cord?
-Lateral inhibition
-Modulation of activity in the cord
What relationship exists between the cord and the DCML?
The higher you are on the cord, the larger the pathway. (i.e. T11 may only have legs and a few other things, while in the cervical cord you may have BUE)
What part of the DCML sends sensory information from the lower part of the body? What’s an easy way to remember this per Schmidt?
-Fasciculus Gracilis
-Gracilis muscle is in the leg**
What part of the DCML sends sensory information from the upper part of the body?
-Fasciculus Cuneatus
Where on the cord does the Fasciculus Gracilis start, per Schmidt?
-L1 or T10
-Information from BLE
What part of the DCML pathway is the Fasciculus cuneatus located?
The most lateral part
What part of the DCML pathway is the Fasciculus gracilis located?
The most medial part
Is the DCML sensitive? What kind of changes can it detect?
-It is very sensitive.
-It can pick up very small pressure changes, i.e. tickles
On the slide where someone was tickled, what color was each feather tickling the foot and the hand?
Foot - blue
Hand - red
What lobe of the brain would a tickle sensation be sent to?
Parietal
If you were tickled on your foot with a feather, what would be the path the signal would take through the DCML?
Tickle –> Dorsal root –> Dorsal root ganglia –> Dorsal column (lowest point; start of Fasciculus gracilis) –> up the cord (Fasciculus Cuneatus joins mid trunk—> Medulla –> Medial lemniscus —> Through the thalamus (ventrobasal complex)–> Internal capsule –> Parietal lobe
Per Schmidt, what area of the Thalamus do tickle sensations go through?
Ventrobasal complex
What is the ventrobasal complex in charge of?
Sending info to the parietal lobe (it’s like a sorting hat)
Where is the internal capsule?
Just outside the thalamus
What is another name for the sensory cortex of the parietal lobe?
Postcentral gyrus
What part of the parietal lobe receives information from the BLE
Top
What part of the parietal lobe receives information from the trunk?
Mid-high
What part of the parietal lobe receives information from the BUE?
Mid-low
What part of the parietal lobe receives information from the face?
Bottom
If you have a stroke in the mid-low area of the parietal lobe, what would be the result?
“messed up sensations”
What kind of picture is used to describe areas of the body that the parietal lobe affects?
Homunculus; slide 27 lecture 5
How does the size of the area on the parietal lobe controlling a specific body part correlate to that body parts size?
It will be proportional; i.e., many more neurons(larger area) working with BLE than the tongue
If a blind person had a stroke in the mid-high parietal lobe, what would be the result? Why?
-They wouldn’t be able to read braille.
-Pressure sensors are in abundance in the hands, but the mid-high area of the parietal controls them.
What two areas of the body did Schmidt stress that we have lots of sensors?
Face, hands, and feet, but he stressed face and hands
Does the trunk have more or less sensors than the arms or legs?
Less sensors than BUE/BLE
Why are pyramidal tracts (the main motor tract) called Pyramidal?
The signal passes through the pyramids in the brain stem
What passes through the internal capsule?
-afferent signals (sensory)
-efferent signals (motor)
What % of motor function is controlled via the Primary Pyramidal tract?
80% (4/5ths)
What path does the Primary Pyramidal Tract take to get to the cell bodies in the anterior horn of the cord?
Signal originates in the motor cortex of the frontal lobe –> Internal capsule (right outside the thalamus) –> Brainstem (Pyramids of medulla; crossover here; AKA pyramidal decussation) –> Lateral corticospinal tracts –> Activation of motor neuron in the anterior horn of the spinal cord
Where are the pyramids of medulla located on the medulla?
Anterior, medial
-“At the very end” - per Schmidt
How are the pyramids of medulla oriented?
-“Crosshatched”
-Horizontal
(Think, it has to get to the other side! so it goes to the…..side).
Tyler-ism™
What is another name for the pyramids of medulla?
Medullary pyramids
What is the area within the medullary pyramids where crossover happens?
Pyramidal decussation
What are the up and down ridges on the medulla?
Pyramids
On the medulla, what is the area of horizontal strands of neurons between pyramids?
Pyramidal decussation
Does the midbrain have pyramids?
-No. Only the medulla has pyramids.
How much motor information does NOT crossover at any point?
2-3% “third motor pathway”
What % of motor information is sent via the Secondary motor pathway?
17%
What is another name for the secondary motor pathway?
Anterior corticospinal tract
Where does crossover happen in the primary motor pathway?
Medullary pyramid
Where does the secondary motor pathway cross over?
At the level of the cord where it has to talk to motor neurons (i.e. travels down same side of the cord where input is until it gets to the level of action, then crosses over)
In which motor pathway does crossover happen superiorly?
Primary motor tract
How many paths does pain follow? What do they have in common?
-Two
-Both relayed through the Spinothalamic or anterolateral tract (interchangeable terminology)
Which pathway does Fast pain take?
Lateral spinothalamic pathway
Which pathway does Slow pain take?
Anterior spinothalamic pathway
What is the main neurotransmitter for Fast pain? and what effect does it have?
Glutamate ; excitatory (fast to release and act)
What type of fibers does fast pain travel on?
A delta fibers (myelinated)
What type of fibers does slow pain travel on?
C fibers (unmyelinated)
What are the pain receptors called?
Nociceptors (free nerve endings)
Where does fast pain get sent to?
Parietal lobe
What does fast pain run parallel to?
DCMLS
In terms of localization, which one is better at localizing, fast pain vs slow pain?
Fast pain –> can tell exactly where injury occurred
Slow pain –> have general idea but can not identify where pain is coming from
Which lamina do slow pain synapse upon in the grey horn?
Lamina II, III & sometimes V
Where do pain pathways cross over to the other side of the cord?
Anterior White Commissure
What is the prefix that can be added to fast pain pathway? (think age)
Neospinothalamic Tract (neo = new)
What is the prefix that can be added to slow pain pathway? (think age)
Paleospinothalamic Tract (paleo = old)
What are the neurotransmitters for slow pain?
- Substance P (Main neurotransmitter)
- CGRP
- Glutamate (slower to act and to release)
Where does slow pain get routed to?
Most slow pain gets routed up to the brainstem or thalamus & not much further
What are a couple of sensors slow pain can be associated to?
Thermoreceptors/heat & vibration sensors
what does slow pain get involved with? (messes with your head)
Emotional centers (are near brainstem)
What is the sloth of tissue at the top of the brain stem where slow pain ends called?
Reticular formation
What is the function of the Vestibulospinal tract? (extrapyramidal)
Maintains balance & eye muscle fixation
What does the reticulospinal tract maintain? (extrapyramidal)
Maintains muscle tone in skeletal muscle
What does the Rubrospinal tract aid in? (extrapyramidal)
Voluntary movement (similar to cerebellum)
The descending pain suppression system is __ in nature & responds to pain
inhibitory
What are the two initial neurons in the DIC? (1st order)
Periaqueductal Gray (near cerebral aqueduct) & Periventricular nucleus (near ventricle)
When the initial neurons are excited what do they release? (1st Order)
Enkephalin
Where does the Enkephalin from first order get released to?
Raphe Magnus Nucleus (RMN –> found in the middle of pons)
What does the RMN release? (2nd order)
Serotonin (5-HT)
Where does 5-HT release at?
Dorsal horn of spinal cord
What does 5-HT act on? and what is released?
Enkephalin neuron ; Enkephalin
What does enkephalin do once its released into the cord?
Binds to enkephalin receptors on the Nociceptor & on the ascending pain receptor pathway & inhibits both reducing pain sensation
In first order DIC is enkephalin inhibitory or excitatory?
Excitatory (excites RMN)
In the spinal cord is enkephalin inhibitory or excitatory?
Inhibitory (binds and shuts down pain receptors)
What is an Enkephalin?
Endogenous morphine analog (all opioid receptors are enkephalin receptors)
In patients with chronic pain, what happens with glutamate receptors?
They get up regulated & system gets more difficult to inhibit
What does a crush, cut, or stab do to a nociceptor?
Depolarizes
If someone is acidotic, what happens to K levels?
Increased
With increased K levels, what happens to nociceptors?
They can depolarize and cause pain
Are patients that are acidotic and need dialysis with high K pain seekers?
No - higher sensitivity to pain due to high K
Why does histamine cause pain?
Inflammation in tissue
What is the difference between serotonin at the cord and in the periphery?
Cord - inhibitory
Periphery - depolarizes nociceptors/painful
What neurotransmitter related to skeletal muscle movement also can result in pain if in the periphery?
ACh
Are prostaglandins painful?
Not by themselves, but they can augment other pain signals and make it worse.
What will inhibiting prostaglandin formation do?
Decrease pain sensitivity
What does the Vestibulospinal tract maintain?
Maintains balance & eye muscle fixation
What does the Reticulospinal tract maintain?
Maintenance of muscle tone skeletal muscle
What does the Rubrospinal tract aid in?
Modulation of voluntary movement (similar to Cerebellum)
What are opioid receptors?
Enkephalin receptors
How do opioid receptors work?
GCPRs, that are bound to K channels –> when activated increase permeability to K –> making them more difficult to excite –> reduced pain signal
Where are opioid receptors found?
on both nociceptor & ascending anterolateral pathway
How do alpha-2 receptor agonists in the nociceptor & ascending anterolater pathway?
Similar to opioid receptors, GCPRs, connected to K channel, activation increases permeability to K –> reduced pain signal
what are the benefits of alpha-2 receptors agonists?
Pain suppression & relaxation in CNS without the euphoria
What are the three alpha-2 agonist mentioned in class from least specific to most specific?
Xylazine, Clonidine & Dexmedetomidine
How do Volatile anesthetics work?
increase K conductance at pain receptors & in CNS –> reduces consciousness & pain
What effect does Nitric Oxide Synthase (NOS) have at the nociceptor?
Increases sensitivity of pain at synapse
How does OTC magnesium help reduce chronic pain?
Magnesium reduces NDMA-R activity by keeping channel from being opened
How does Cox2 affect the pain pathway?
it is expressed in the nociceptor in response to pain & produces prostaglandins –> increasing the sensitivity to painful stimuli on both nociceptor & ascending pain pathway
When we are born, what type of nACh-Rs do we have?
Immature (fetal) nACh-R
If the muscle is not contracting or confirmation of contraction does not get back to the brain, what is the compensation mechanism?
The skeletal muscle will increase nACh-Rs, but they are mostly fetal nACh-Rs and are placed all over the skeletal muscle not just NMJ
What is the difference between a immature nACh-R and an Adult nACh-R?
- fetal nACh-R: slow ion conductance & stay open for a longer period of time
adult nACh-R: high conductance, active for a short period of time
What are the binding sites in a neuronal nACh-R?
it has 5 a7 binding sites, found in neuronal muscle
What affect does succs have on immature nACh-Rs?
it has even greater affect –> really long period of time they stay open
What is the junctional area?
Area where nACh-R are found, NMJ
What is the Peri-junctional area?
area right outside junction
What is the post-junctional area?
area away from junctional area
Where do you place electrodes to see what affects paralytics are having?
Motor neurons
What do the electrodes produce when a current is applied?
Action Potential (depolarization)
If you run a current on a motor neuron and see a big contraction, what does that tell you in regards to your paralytic?
The block is NOT deep enough
If you run a current on a motor neuron and dont see a contraction, what does that tell you in regards to your paralytic?
The block is deep
What kind of current runs through electrodes? and what affect does this have on the cell membrane?
Electrons runs through the current & generate an action potential by making outside of cell negative & eliminating charge difference (no more polarity)
What is the term for a stimulus strong enough to recruit all underlying motor neurons?
Supramaximal Stimuli
What is a single twitch setting on a nerve stimulator?
One impulse & see what happens
What is the train of four?
repetitive stimulation - 2Hz at 2secs –> two impulses at 1 second x2 = 4 total switches
In which NMB agent would we see differences in magnitude of responses on a chart?
NDMR
In which NMB agent would we see similar magnitude of responses on a chart?
Depolarizing muscle relaxant
Describe tetanic stimulation
high frequency stimulation for a short period of time
Describe Post-tetanic count (PTC)
impulses muscle generates after a period of tetanic contraction
Describe Double Burst Stimulation
high frequency stimulation for a couple seconds, take a break, high frequency stimulation for a couple seconds
Where is the most common place to place electrodes to test NMB agents?
Ulnar nerve
The Ulnar nerve stimulates which muscle?
Adductor Pollicis
Where are other places to place electrodes to test NMB agents?
peroneal nerve, Ophthalmic branch of facial nerve, & posterior tibial nerve
What is the typical onset for NDMR & Succs?
NDMR - a few minutes
Succs - fast onset
Why is Succs popular in use?
Fast onset, cheap & short acting
If we were to graph the recovery from a NDMR, what would the graph look like?
difference in amplitude, with the first twitch amplitude being the highest and gradually declining in an exponential manner
If we were to graph the recovery from a Depolarizing muscle relaxant, what would the graph look like?
Equal amplitude in each twitch gradually increasing until recovery
What is the TOF ratio for NDMR?
a fraction (B/A)
- B = strength of contraction of last twitch
- A = strength of contraction of first twitch
Early on in the recovery from a NDMR, what would the TOF ratio look like
<1, very small
Near full recovery from a NDMR, what would the TOF ratio look like?
gets close to 1
What would you expect the depolarizing muscular blocker TOF ratio to look like?
very close to 1
What are ACh-R found on the motor neuron called?
Aphla3-Beta2 ACh-R
What is another name for ACh-Rs found on the motor neuron?
Autoreceptors
how do alpha-3 Beta-2 ACh-R (autoreceptors) get activated?
ACh dumped into synapse feeds back & binds to autoreceptors
What is the current that comes in through autoreceptors?
Na & some Ca
What purpose does the current that comes in through the autoreceptors serve?
move forward VP-1 ACh into VP-2 ready position
What affect do NDMR have on autoreceptors?
They bind to ACh autoreceptors and block it, preventing influx current –> leading to less VP-1 moving into the VP-2 ready position –> weaker contraction with repeated stimulation in TOF
What affect do depolarizing muscle relaxant have on autoreceptors?
They bind to ACh autoreceptors & elict depolarization –> influx of current –> VP-1 gets moved into VP-2 –> equal amplitude of contraction in repeated stimulation in TOF
How is succs degraded?
by plasma cholinesterase
How many ACh are required to activate autoreceptors on motor neuron?
3 must bind
What is the Artery located in the Anterior median fissure?
Anterior Spinal Artery
How many Posterior spinal arteries do we have? & why?
2 ; posterior median fissure not deep enough house a large artery
Where do the Posterior spinal arteries obtain their blood from?
Vetebral arteries (found in neck), Cerebellar Arteries (anterior inferior & posterior inferior cerebellar arteries) & Radicular arteries
Where do Radicular arteries branch from? and what do they feed into?
Intercostal Arteries –> anterior & posterior spinal arteries
What is the feeding pattern look like for Radicular arteries?
Irregular, normally have one radicular artery feeding into front or back & can come from either side
What are other terms for Radicular arteries?
Medullary arteries, Segmental arteries & a combination of both –> Segmental medullary artery
What are the arteries on the outer surface of the cord?
Coronal arteries
Do the spinal cord arteries have collaboration?
No, loss of an artery will induce damage
How does the vein setup differ from the artery set up?
A posterior spinal vein is found in the middle
At every level we should have __ coming off the dorsal branch of the intercostal arteries
Spinal branch
What are the intercostal arteries responsible for?
keeping the rib cage perfused
What supplies the small intestines with blood?
Mesenteric artery
What are we concerned about when it comes to having to repair Triple As?
Clamping Aorta & preventing perfusion to spinal cord
What is the main source of blood supply for Radicular arteries?
Aorta
How much blood is supplied by the Anterior spinal artery & the posterior spinal artery?
Anterior spinal artery - 75%
Posterior spinal arteries combined - 25%
- about 12.5% each
Loss of which spinal artery would be detrimental?
Anterior spinal artery (supplies 75% of the blood to spinal cord)
In a typical patient, how many Anterior Feed arteries come in from the neck, thorax, & lumbar?
Neck - 2
Thorax - 2-3
Lumbar - 1-2
Which vessel supplies 2/3 of arterial blood to lower part of spinal circulation?
The Great Radicular Artery (GRA)
- Artery of Adamkiewicz
Where does the GRA typically enter from?
Left side
Where can the GRA typically be located, what are the ranges & what is the Absolute rage?
Normally Located T-10
- Can range between T-9 to T-12
- Absolute range is T-5 to L-5
Cross clamping below GRA, what is the concern?
There is no concern as GRA is still being supplied
Cross clamping above GRA, what is the concern?
Concern for paralysis or loss of motor function of lower body due to no blood supply from GRA
- may see some sensory dysfunction but main concern is motor
How is cross clamping above GRA avoided?
Using imaging
- that is if time permits, may have to clamp in an emergency
What is the ideal origin of the GRA, for to originate high or low?
High –> more room to clamp below –> safer
(if it originates low it is much easier to obstruct)
What is the top way that leads to an increase in CSF pressure in the spinal cord?
Cross clamping in Aorta
On average aortic cross clamping increases CSF pressure by how much?
10mmHg
What is normal ICP?
10mmHg
How can you get around an increase in CSF pressure caused by aortic cross clamping?
use a drain to decrease CSF & decrease perfusion pressure
Prolonged ischemia (cross clamping) can lead to cell death, what are somethings that can be done to slow this process?
Anything that reduces inflammation & drugs that slow down metabolic rate
Sudden restoration of blood flow in a vessel can cause what?
Ischemic Re-perfusion
What happens in Ischemic Re-perfusion?
massive return of blood to which tissue can not handle at once (overloaded with oxygen)
What defends against oxygen induced damage?
Antioxidants
What can you do to prevent ischemic re-perfusion?
slowly return blood flow
What does the body use to destroy stuff?
Oxygen (oxidation)
What are the tracts that send information to Cerebellum that aid in complicated movements?
Spinocerebellar Tracts
What are the two Spinocerebellar tracts?
Anterior Spinocerebellar tract & Posterior Spinocerebellar tract
What kind of information does the Anterior spinocerebellar tract send & where does it send it to?
information regarding activity in anterior horn & gets sent to
- Superior Cerebellar Peduncle (bundle of axons) - aids in motor movement
What kind of information does the Posterior spinocerebellar tract send & where does it send it to?
Information about tendons & muscle spindles & gets sent to
- Inferior Cerebellar Peduncle (aids in movement)
Differentiate Parietal and Visceral pain. Which is localizable?
Parietal - Parietal is localizable. Tissue pain; more tactile receptors.
Visceral - Deep organ interior. Not localizable. Less tactile receptors.
Would parietal or visceral pain have referred pain?
Visceral
What nervous system is visceral pain sent through?
Autonomic
What is pain threshold?
Ease or difficulty of giving someone pain
What happens after you’re in pain for a long time?
Upregulation of nociceptors, makes things more sensitive/painful. Also can impact emotions
What happens to the pain threshold in individuals that have a pain tolerance?
Threshold is raised
Where is the parietal pain from the appendix felt?
LRQ
In general, sharp/fast/localized pain will be ____ pain that is carried in ___ fibers
Parietal; A fibers
What kind of sensations are associated with visceral pain? What kind of fibers are they likely transmitted through?
Dull, achy, poorly localized
C-fibers
In regards to visceral referred pain, where would the kidneys hurt?
Back
What two organs don’t have visceral pain sensors?
Liver & lungs (wouldn’t feel pain after drinking or smoking for 30 years)
Can organs have both parietal and visceral pain? What organ is an example?
Yes; it can change the pain pathway depending on what is activated.
Appendix
Can appendix pain be relieved with lateral inhibition?
Yes
When releasing lateral inhibition pressure on the appendix, what happens?
Daddy says hurts like hell
Where is visceral appendix pain felt? Is it affected by lateral inhibition?
T10; cannot be suppressed
Where is referred pain from the heart? Why is this?
Left chest/left arm
Right side of the heart is not as prone to ischemia, left is though therefore referred pain to the left
(If pressures were equal on both sides, would have pain on both sides of chest)
Where is visceral referred pain of the stomach? What is it often confused with?
Maybe a heart worm per Schmidt, feel it little higher than umbilical
MI
“Ouch! My back hurts.” - patient
Where is this persons pain coming from?
Either kidneys or back injury
Where does the limbic system sit? What feeds into this?
Right on top of the brain stem
Slow pain; messes with your emotions and amplifies pain
Does fast pain mess with emotional state?
No
What are the three areas of the brain associated with the limbic system?
Amygdala, hypothalamus, cingulate gyrus
Where is the cingulate gyrus located? Is it still considered to be part of the cerebral cortex?
Deeper structure/gyrus located just outside the corpus collosum.
Yes
What does the cingulate gyrus do?
Processes some of the slow pain information
Where is fast pain processed?
Periphery of parietal lobe
What type of nerve fiber does the ANS use? Do we perceive this?
Type C; No
Which nerve fiber is considered to be well developed, more efficient, and faster? What neuron is it typically associated with?
Type A; motor
What type of nerve fiber does the muscle spindle feedback receptor use?
Type A; large
What type of nerve fiber do the muscle tendons use? What are they?
Type A; safety mechanism to make sure the tendon does not rip out of a bone
What type of nerve fiber do the various pressure sensors use around the body?
It varies depending on function
Where do pressure sensors get fed into? What fibers does this consist of?
DCML; variety of A-alpha, beta, gamma, delta
Generally, what kind of neurons make up the DCML pathway?
Large myelinated neurons (type A)
What kind of nerve fiber makes up the lateral inhibition fiber? Where does this ascend to the brain?
A-Beta fiber; DCML
What type of nerve fiber makes up the crude senses? i.e. ache, dull, nausea pain, cold, warm. Is this information “slow?”
Type C
While slower than type A, it’s still a fraction of a second because it is an action potential. It’s just slower than myelinated