NEURO - Pain/Temperature Flashcards
Large myelinated fibers
A delta fibers
Small umyelinated fibers
C Fibers
C fibers respond to broad range of painful stiumuli
mechanical
thermal
chemical
Plasticity
the adaptable change in structure, and function of the brain
Gate control theory of pain
Pain is modulated by a gate in the cells of the SUBSTANTIA GELATINOSA in the SPINAL CORD
Gate control theory: Pain is modulated by a ___________in the cells of the______ _______ in the ________
gate in the cells; SUBSTANTIA GELATINOSA; SPINAL CORD
*****Transduction
when tissues is damaged due to exposure to chemical, mechanical and thermal noxious stimuli converted to action potential
Conduction
from delta and C fibers to interneurons in dorsal horn of spinal cord
Interneuron does what
can excite or inhibit signal to second transfer order neurons.
Transmission
Pain signals from delta and C fibers.
**Myelinated A-delta fibers: Transmission is _____and conveys ______and ______pain.
fast ; sharp and localized pain.
Unmyelinated C polymodal fibers: Transmission is _______ and conveys _______, _______ and _____sensations.
Transmission is slower and conveys dull, diffuse burning and aching sensations.
Fast pain neurons synapse with _______ _____________
secondary neurons at the Dorsal Horn.
A- beta
Large,
fast
sense mechanical touch and vibration
can modulate A delta and C fibers
A- beta
Large,
fast- 70m/s, myelinated
sense mechanical touch and vibration
can modulate A delta and C fibers
A- Delta
Size, speed, type
Medium
10m/s
sharp, localized
sense mechanical/extreme temperature
C-fibers
Small
slow spee d 1m/s
dull, diffuse pain signal
sence mechanical/thermal/ chemical
First order neuron
Nociceptors: respond to chemical, mechanical and thermal stimuli.
2nd order neuron
interneurons in the dorsal horn
Function as a pain gate to regulate pain transmission.
****Cross over in the spinal cord and ascend.
3rd order neuron
afferent neurons in the spino-thalamic tract.
Delta fibers
laminae 1+ 5
C fibers
1, 2
A- Beta
3,4
Lamina 3, 4, 5, send signals to where?
Send signals to Hypothalamus & AMYGDALA
Lamina 2 inhibit
Lamina 1
C fibers synapse with interneuron within the __________ -_________ prior to decussation.
substantia gelatinosa
Activation of the reticular system by _________ fibers results in ________ __________when in pain
Reticular System; C fibers; difficulty
sleeping when in pain.
Activation of the ______ ______ by ________ results in distress and anxiety.
Limbic System;C fibers;
Postsynaptic 2nd Order neurons have ______ ________receptor.Normally inactive because ordinarily blocked by _______ ions. However, intense, prolonged pain signal releases Mg and ______ __________ to occur.
NMDA
(N-methyl-D-aspartate) ; Mg++ ions.
Mg and allows
postsynaptic depolarization to occur.
- 2nd Order Neurons can be _____ _______Or _______
* Peripherally – NSAIDS: _____ ______(Ex: ____and ___-)
-Suppressed or
Facilitated Peripherally or Centrally
cox inhibitors (Ibuprofen, ASA, etc)
– Local Anesthetics: __________ (ex: __)
block Na+ channels (lidocaine)
– Hydrocortisone: actions
lipocortin-1 – blocks
prostaglandins/leukotrienes from arachidonic acid
TENS (Transcuteneous Electrical Nerve stimulators) Unit or Mechanical Stimulation: does what? Stimulates ________ to release ______ and______ , inhibits ______ preventing ______
stim.s A-beta fibers to release GABA & glycine, inhibits glutamate preventing depolarization
Cite 2 Pain excitatory neurotransmitters
Glutamate (released by a-delta fibers), aspartate
Glutamate and aspartate are released by __________ and are (exc/inh) ______Neurotransmitters.
A Delta fibers, Pain excitatory
Pain inhibitors (analgesic system) Serotonin, gamma-aminobutyric acid (GABA), glycine, Opioids: (endorphins, enkephalins, dynorphins), norepinephrine
Serotonin, gamma-aminobutyric acid (GABA), glycine,
Opioids:
(endorphins, enkephalins, dynorphins), norepinephrine
___ _____ releases NE to Dorsal horn
Locus Ceruleus
Releases 5HT serotonin to Dorsal horn
Nucleus Raphe
Nucleus Raphe
Releases 5HT serotonin to Dorsal horn
Periaqueductal gray matter releases what to where?
releases
Enkephalins to Nucleus raphe magnus
releases Enkephalins to Nucleus raphe magnus
Periaqueductal gray matter
____ _________in the midbrain is the coordinating center of the descending analgesic system
Periaqueductal gray matter
_______ acts via the ______ _________in the brain stem, to send
PAGM ; raphe nucleuslocated in the brain stem to send analgesic impulses to block pain transduction at the first order neuron-second order neuron synapse (at the dorsal horn).
_______ and _______which are opioids are the neurotransmitters released by the descending analgesic neurons.
Opioids (endorphins and enkephalins)
Analgesic pathways also use ______, _______ and _______
Serotonin, Norepinephrine, and GABA
Pain Modulation , definition
“the physiologic process of suppressing or facilitating pain”.
Descending modulation of pain
Descending analgesic pathways are found where ?
Descending analgesic pathways are found in the dorsolateral tracts.
Pain reaches the brain via the ____ _______tract. It carries the most _____ ______
Lateral Spinothalamic Tract.; the most nociceptive information.
Affective component of pain is ____ ______ ______
the distress (anxiety) that goes with pain.
Autonomic component
“sympathetic” – effect on HR, BP, resp,
“sympathetic” – increases HR, BP, sweating, respiratory
Pain Threshold: Point at which _____
Does it significantly vary among people. ?
Is the point at which a stimulus is perceived as pain (patient becomes aware).
• Does not significantly vary among people or in the same person over time.
Nonsteroidal anti-inflammaatory drugs
reduce ________ by _______
hyperalgesia by decreasing prostaglandins.
Acute Somatic
• Arises from ________
**• A-delta fibers: Pain is _____ and _____localized.
**C fibers: Pain is _____, _____,_____ and poorly localized
connective tissue, muscle, bone, and skin. Pain is sharp and well localized. Pain is dull, aching, throbbing, and poorly localized.
What is referred pain?
Predictable pain
can be ___ or ____
Pain in an area in part of the body distant from its point of origin.
Predictable - referred pain is supplied by same spinal segment as actual site.
Can be acute or chronic.
Injured nerves become _______Example: _______
Hyperexcitable. Example: Carpal Tunnel
Temperature regulation:is controlled by?
Thermoregulation: Is controlled by Central Thermo-receptors in the Hypothalamus
What are EXOgenous pyrogens,________
Endotoxins produced by pathogens
Endogenous pyrogens:
Prostaglandin-E2 (PGE2) interleukin-1 (IL-1) IL-6 tumor necrosis factor–alpha (TNF-α), interferon-γ
__________Is a life-threatening complication of an inherited muscular disorder. What happens in Malignant hyperthermia??
Increased calcium release or decreased calcium uptake with muscle
contraction
Sustained muscle contractions
Increased oxygen consumption and lactic acid production
__________Is precipitated by the administration of volatile anesthetics and
depolarizing neuromuscular-blocking agents.
Malignant Hyperthermia
Treatment of Malignant Hyperthermia
Remove the agent
Dandrolene
Malignant Hyperthermia can cause ______,______,and _______
Cardiac dysrhythmia, tachycardia, and hypotension
Most common chronic pain condition
low back pain
Second most common pain syndromes
Myofascial pain
Chronic post op pain
disruption or cutting of sensory nerves.
Deafferentation pain
Sympathetic dystrophies
Hyperesthesias
Increased sensitivity and decreased pain threshold to tactile and painful stimuli
Phantom Limb Pain
Associated with stroke
41° C (105.8° F):what happens
Nerve damage; convulsions
43° C (109.4° F): what happens ?
Death
What is heat cramp associated with ?
Prolonged sweating and associated sodium loss cause severe spasmodic cramps
in the abdomen and extremities.
What happens in heat exhaustion
Dehydration, depressed plasma volumes, hypotension, decreased cardiac output, tachycardia
Heat stroke
potentially lethal result of breakdown in an overstressed thermoregulatory center.
• Brain cannot tolerate temperatures higher than 43° C (109.4° F).
– Cardiovascular and thermoregulatory centers may cease functioning in high
temperatures.
Administration of _________ can cause malignant Hyperthermia
Succinylcholine
Be able to differentiate Malignant hyperthermia to
Thyroid Storm
Pain is
Unpleasant sensory and emotional experience with actual or potential tissue damage.
Patterning theory
theorizes that somatic receptors of variable sensitivity.