Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dental Neuroscience > neurobiology of pain > Flashcards

neurobiology of pain Flashcards

1
Q

what is pain?

A

an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

pain can be classified by:

A
  • underlying etiology
  • anatomic location
  • temporal nature
  • intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

underlying etiology can be

A
  • nociceptive
  • inflammatory
  • neuropathic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

anatomic locations of pain:

A
  • visceral
  • somatic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

duration of pain:

A

acute
chronic
acute on chronic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

pain instensities

A
  • mild (1-4 ratings)
  • moderate (5-7 ratings)
  • severe (8-10 ratings)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

nociceptive pain

A
  • the result of direct tissue injury from a noxious stimulus
  • ex: bone fracture, new surgical incision, and acute burn injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

inflammatory pain

A
  • the result of released inflammatory mediators that activates nociceptors
  • ex: appendicitis, meningitis, rheumatoid arthritis, inflammatory bowel disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

neuropathic pain

A
  • the result of injury to nerves leading to an alteration in sensory transmission
  • can be central or peripheral
  • ex: diabetic peripheral neuropathic pain, postherpetic neuralgia, chemotherapy induced pain, and sciatica
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

acute pain

A
  • lasts less than 3 months
  • neurophysiological response to noxious injury that should resolve with normal healing
  • ex: post-op pain, fractured bones, appendicitis, crush injury to finger
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

chronic pain

A
  • lasts more than 3 months
  • beyond expected course of an acute disease or after complete tissue healing
  • ex: low back pain, most neuropathic pain syndromes, and chronic pancreatitits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

acute on chronic pain

A
  • times of acute exacerbations of a chronic painful syndrome or new acute pain in a person suffering from a chronic condition
  • ex: sickle cell exacerbation in a patient with sickle cell disease or an abcess in a patient with sickle cell disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

pain intensity is determined by

A
  • pain assessment scores
  • combined with history and physical exam
  • subjective
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pain is part of _________ sensation

A

normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

pain sensation

A
  1. sensory receptor detects stimulus
  2. sensory neuron conduct nerve impulse to spinal cord then to brain or straight to brain
  3. brain interprets
  4. brain’s interpretation of the info is a perception or understanding of the stimulus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

nociceptors

A

cell bodies of pain sensing neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where are nociceptors located

A

DRG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A(theta) and C DRG neurons are types of

A

nociceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A(theta) and C DRG neurons

A
  • pseudo-unipolar neurons which has one extension from the cell body and split into 2 branches
  • peripheral branches send free nerve endings to end organs (skin, muscle,)
  • central branches from dorsal roots entering spinal cord dorsal horn, synapse on secondary motor neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

A(theta) nociceptors

A
  • small-medium neurons
  • thin myelinated axons
  • respond to mechanical/mechanothermal stimuli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

C nociceptors

A
  • small neurons
  • unmyelinated axons
  • respond to mechanical, thermal, and chemical stimuli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

A(theta) fiber has ________, _______ pain

A

fast, sharp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

C fibers have ______, ___________ pain

A

slow, aching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

A(theta) and C nociceptors send

A

peripheral branches (fibers) that form free nerve endings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

free nerve endings (cutaneous nociceptors)

A
  • receive directly external painful stimuli
26
Q

cutaneous nociceptors are classified by responses:

A
  • mechanical
  • thermal (temp extremes)
  • mechano-thermal
  • polymodal (mechanical, thermal, and chemical stimuli)
27
Q

fibers and nerve endings

A
28
Q

transduction of pain signals

A
  • noxious stimuli active cutaneous nociceptors
  • signals transmitted to cell bodies of nociceptors in DRG to activate nociceptors
  • AP are produced in nociceptors
  • electrical signals are then transmitted through central branches to spinal dorsal horn to activate the secondary neurons
29
Q

why cutaneous nociceptors can sense pain stimuli?

A

special receptors or ion channels expressing on cutaneous nociceptors respond to different external stimuli

30
Q

2021 nobel prize in physiology or medicine was for

A

discovery of receptors for temp and touch

31
Q

transmission of pain signals

A
  • electrical signals are transmitted to secondary order neurons in spinal cord dorsal horn
  • C afferent fibers mainly terminate in superficial gray matter laminae I-II of the spinal cord
  • A(theta) afferent fibers terminate in both superficial and deep laminae
32
Q

major neurotransmitters involved in transmission of pain signals

A
  • EAA: glutamate, aspartate
  • Substance P (neuropeptide)
  • calcitonin gene related peptide (CGRP)
33
Q

pain sensation: referred pain

A
  • pain from visceral nociceptors is poorly localized
  • can be felt on surface areas
  • knowledge of referred pain maps important in clinical diagnosis
  • somatic and visceral afferents may converge on same 2nd order neuron
34
Q

transmission (cont)

A
  • pain signals are carried out to different brain regions through ascending pathways
  • lateral pathways
  • medial pathways
35
Q

lateral pathways

A

spinothalamic tracts
- transmits discriminative info about the location, quality, and intensity of input

36
Q

medial pathways-

A
  • spinoamygdalar tract
  • spinohypothalamic tract
  • medial spinothalamic
  • spinoreticular
  • other spinolimbic tracts
  • activate affective, alerting, motivational, autonomic and escape responses in pain (suffering, anxiety, increased attention, arousal, memory, inc. heart rate, BP)
37
Q

different cortical and subcortical areas are activated by noxious stimulation to produce:

A
  • pain sensation
  • emotional
  • cognitive reactions
38
Q

modulation: inhibition

A
  • inhibitory mechanisms are activated during transmission of pain signals to terminate or reduce pain sensation
  • descending pathways inhibit pain
39
Q

how do descending pathways inhibit pain?

A
  • originates in cortex, thalamus, midbrain (periaqueductal gray) and brain stem
  • send axons to spinal dorsal horn and inhibit pain signal transmission
40
Q

main neurotransmitters of pain inhibition

A
  • norepinephrine
  • serotonin
  • dopamine
  • endogenous opioids
41
Q

descending inhibitory pain pathway

A
42
Q

gate control

A

theory that offers a physiological explanation for the previously observed effect of psychology of pain perception
- inhibited pain signals by activating inhibitory pain neurons

43
Q

orofacial pain

A

trigeminal nerve contributes to a lot of orofacial pain

44
Q

trigeminal nerve

A
  • largest CN
  • sensory and motor
  • 3 branches (opthalamic, maxillary, mandibular)
45
Q

trigeminal ganglion

A
  • site: occupies a depression in the middle cranial fossa
  • importance: contains cell bodies whose dendrites carry sensations from the face and the axons form the sensory root of the trigeminal nerve
46
Q

4 nuclei of trigeminal nerve

A
  1. mesencephalic
  2. principal
  3. spinal
  4. motor
47
Q

mesencephalic nucleus

A
  • midbrain and pons
  • receives proprioceptive fibers form face
48
Q

principal (main) sensory nucleus

A
  • pons
  • receive touch fibers from face
49
Q

spinal nucleus

A
  • pons, medulla, and upper 2-3 cervical segments of spinal cord
  • receives pain and temp from face
50
Q

motor nucleus

A
  • pons
  • 4 muscles of mastication
  • other 4 muscles (ant. belly of digastric, mylohyoid, tensor tympani, and tensor palati)
51
Q

ascending pathways for orofacial pain

A
  • pain signals from face are carried to thalamus thru trigeminothalamic tract, mostly crossed
  • thalamic projections go to sensory cortex corresponding to face area
  • secondary axons from TN project to insula basal ganglia, anterior cingulate cortex, parabrachial area, amygdala, limbic circuitry
52
Q

trigeminal neuralgia

A
  • compression, degeneration or inflammation of 5th CN may result in this (tic douloureux)
  • characterized by episodes of intense stabbing, excoriating pain radiating from angle of jaw along a branches of the trigeminal nerve
  • usually involves maxillary and mandibular nerves
  • rarely in ophthalmic division
53
Q

trigeminal neuralgia image

A
54
Q

treatment of trigeminal neuralgia

A

1st: pain meds
2nd: stronger meds
3rd: surgery
alternate: other meds

55
Q

nerve innervation of teeth

A
  • nerves originate from superior and inferior alveolar nerves
  • innervate odontoblastic layer of pulp cavity
  • enter tooth by apical foramen
  • branch to form sub odontoblastic nerve plexus of raschkow
56
Q

hydrodynamic theory

A
  • explains dentine hypersensitivity
  • different types of stimuli are on exposed dentine
  • increase fluid flow through the dentinal tubules
  • activate mechanoreceptors on the pulp nerves
57
Q

special receptors and ion channels expressed on ____________ and _________ ___________ also respond to external stimuli

A

odontoblasts, nerve endings

58
Q

pharmacological treatment of pain

A
  • target peripheral nociceptors
  • target pain transmission centrally
59
Q

target peripheral nociceptors

A
  • local anesthetics (lidocaines, bupivacaine): block sodium channels
  • anti-inflammatory drugs (NSAIDS): inhibit cyclooxygenase (COX1 COX2) to reduce inflammatory mediators such as prostaglandins
60
Q

target pain transmission centrally

A
  • antidepressants (SNRI, SSRI, NRI, TCA): boosting serotonin and /or norepinephrine levels to activate descending inhibitory pathway
  • opioids (morphine, oxycodone): activating opioid receptors to reduce pain transmission (spinal and supra spinal levels)
  • anti-convulsant (carbamazepine, topiramate, valproic acid, gabapentinoid): block central Na or Ca channels

Dental Neuroscience (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions