Pain part 2

Question 1

mechano receptors are ___ afferent fibers

• meissner, pacinian
• merkel’s, ruffini

Answer 1

A beta

Question 2

free nerve ending mechanoreceptors are

Answer 2

A delta and C fibers

Question 3

warm receptors are ___ type

Answer 3

C

Question 4

cold receptors are ____ type

Answer 4

A delta

Question 5

mechanical and thermal nociceptors are ____ type

Answer 5

A delta

Question 6

polymodal nociceptors are ___ type

Answer 6

C

Question 7

are A beta myelnated

Answer 7

yes

Question 8

are A delta myelinated

Answer 8

little

Question 9

are C type myelinated

Answer 9

no

Question 10

nociceptor impulses are transmitted by

Answer 10

A delta and C fibres

Question 11

A delta activation results in

Answer 11

glutamate release at synapse with 2nd order neuron in dorsal horn

Question 12

C fibre activation results in

Answer 12

glutamate and sub P release

Question 13

fast pain has ___ receptive fields

Answer 13

small

Question 14

slow pain has ____ nociceptors and ___ receptive fields

Answer 14

polymodal

large

Question 15

3 types of pain

Answer 15

nociceptive
inflammatory
pathological

Question 16

hyperalgesia

Answer 16

exaggerated response to stimuli

Question 17

allodynia

Answer 17

sensation of pain to innocuous stimuli

Question 18

peripheral sensitization process

Answer 18

bradykinin or prostaglandin released = sensitize nociceptors = release substance P and CGRP

sub P = histamine release from mast cells

CGRP = dilates blood vessels = release more bradykinin

Question 19

ventrolateral spinothalamic pathway

Answer 19

primary - dorsal horn - decussates - ascends contralaterally in anterolateral column - thalamus - primary somatosensory cortex

Question 20

pain in viscera is felt as pain on surface of the body

Answer 20

referred pain

Question 21

referred pain is based on what theory

Answer 21

convergence projection theory

Question 22

neuropathic pain

Answer 22

caused by damage/ dysfunction of nerves (central or peripheral)

burning sensation that happens on its own or by a light touch

can result in hyperpathia

Question 23

central sensitization is due to

Answer 23

projection neuron sensitization- more responsive to inputs

Question 24

sensitization of the projection neuron results in

Answer 24

disinhibtion = insignificant inputs form other afferents such as A beta mechanoreceptors can now activate the projection neuron

• secondary hyperalgesia
• allodynia

Question 25

main excitatory NT in CNS

Answer 25

glu

Question 26

glu receptors are

Answer 26

ionotropic

Question 27

3 types of glu receptors

Answer 27

AMPA
kainate
NMDA`

Question 28

LTP is a key trigger for

Answer 28

central sensitization

• opening of NMDARs

Question 29

substance P and CGRP result in

Answer 29

LTP like results
- phosphorylation of AMPARs and NMDARs = central sensitization

increased depolarization of postsynaptic neuron

activate pathways that lead to release of Ca2+ from smooth ER

Question 30

site of release of subP and CGRP results in

Answer 30

diffucion away from activated synapse = facilitates neighboring synapses

Question 31

phosphorylation as a LTP like mech results in

Answer 31

increased sensitivity of AMPARs and NMDARs- NMDARs opened longer

AMPARs can now let Ca2+ in

increased number of AMPARs inserted

Question 32

calcium effects for LTP like mech

Answer 32

activates enzyme NO synthase = paracrine = increase Glu release

activates COX2 = PGE2 = paracrine = increased Glu

Question 33

transcription effects of LTP like mech

Answer 33

1. increased synthesis of AMPARs

2. increased synthesis of NK1, COX2, other proalgesic protein

Question 34

NK1 is the

Answer 34

receptor for sub P

Question 35

disinhibition as a central sensitization mech

Answer 35

PGE2 affects gly receptor = decreased gly inhibition onto projection neuron

Question 36

primary hyperalgesia

Answer 36

within normal receptive fields

Question 37

secondary hyperalgesia

Answer 37

central- normally insignificant inputs from outside nociceptors are now able to activate the sensitized projection neuron

Question 38

allodynia

Answer 38

peripheral = decreased threshold of nociceptor receptors = can be activated by non noxious stimuli
central = normally insignificant inputs from A beta afferents are now able to activate the sensitized projection neuron