Lecture 4- peripheral pain Travers Flashcards

1
Q

Which types of fiber makes up the majority of cutaneous nociceptors?

A

C fibers (87%)

A delta are the 13%

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2
Q

Are C fibers myelinated?

A

no

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3
Q

Are A delta fibers myelinated?

A

yes lightly

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4
Q

Which fibers are responsible for “first pain” which is sharp and well-localized

A

a delta

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5
Q

Which fibers are responsible for dull, burning, and lasting pain?

A

c fibers

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6
Q

What kind of channels do a delta fibers have

A

Na channels: TTX sensitive

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7
Q

What kind of channels do C fibers have

A

Na channels: TTX sensitive and TTX resistant

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8
Q

branches of trigeminal with prominent chemethesis

A
  1. ethmoid from V1
  2. posterior palatine from V2
  3. Nasopalatine from V2
  4. Lingual from V3
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9
Q

capsaicin can exhibit

A

desensitization

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10
Q

dentinal tubules are innervated by… and they contain… and are important in… and… sensitivity

A

A delta fibers

  • calcitonin gene related peptide
  • mechanical and thermal
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11
Q

pulp chamber is innervated by … fibers, conatin…. and exhibit ….. sensitivity and chemosensitivty to ….

A

C
substance P
thermal

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12
Q

pulpal C fibers respond to inflammatory mediator….

A

bradykinin

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13
Q

NH4CL and NaCl produce more of a …. pain andhistamine and bradykinin produce more of a …. pain

A

sharp

dull burning

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14
Q

3 characteristics of hyperalgesia

A

prolonged spontaneous and response to non painful stimuli

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15
Q

hyperalgesia- thermal or mechanical injury: C fiber responds and releases…. and then SP stimulates…. which release… and stimulate…

CGRP causes…. which is a …. to C fiber

A
  • neuropeptides substance P or CGRP
  • mast cells
  • histamine
  • C fiber
  • vasodilation and swelling
  • mechanical stimulus
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16
Q

Hyperalgesia: damage that causes bleeding, same as thermal and mechanical AND ….. –>…. formation which stimulates …. and … products from…. which stimulates….

A
bradykinin
clot 
C fiber
platelet
5HT (serotonin)
C fiber
17
Q

Hyperalgesia: damage leading to infection and immune response can cause sensitization, ….. sensitize C fiber rather than causing direct excitation. …. also sensitize C fibers and protons released in inflamed tissue stimulate …. receptors and produce sensitization

A
  • prostaglandins
  • cytokines
  • vanilloid/TRPV1
18
Q

A fibers Na channels are…. sensitive (… threshold) and K channels are….. (… conductance)

A

TTX, low threshold

BK, big conductance

19
Q

C fibers Na channels are…. resistant (…threshold) and K channels are….. (… conductance)

A

TTX, high threshold

BK and SK, small conductance

20
Q

prostaglandins block…. channel

A

SK

21
Q

Sensitization of vanilloid receptor (TRPV1): inflammation leads to lower threshold by:

  1. presence of ….
  2. …. of VR1 receptor
  3. … in receptor #

Receptor is now activated at 22C instead of 42C

A
  • inflammatory mediators (bradykinin/protons)
  • Calcium activated phosphorylation
  • increase