Pain experience

Question 1

where would you find high numbers of nociceptors?

Answer 1

cornea and tooth pulp

Question 2

where would you find low numbers of nociceptors?

Answer 2

brain, liver lungs

Question 3

what are free nerve endings in tissues, attached to nerve fibres?

Answer 3

nociceptors

Question 4

what nerve fibres are nociceptors attached to?

Answer 4

c fibres
ADelta

Question 5

what type of pain do C fibres result in?

Answer 5

slow, burning pain

Question 6

what type of pain do Adelta fibres result in?

Answer 6

sharp, pricking pain

Question 7

what is the resting membrane potential?

Answer 7

-70mV

Question 8

What must the membrane potential reach to stimulate an action potential (THRESHOLD)?

Answer 8

-50mV

Question 9

how do inflammed tissues cause a potential change?

Answer 9

they release chemicals and bind to protein channels

Question 10

what do protein channels change shape in response to?

Answer 10

different temperatures

Question 11

what protein activates a response at high temperature and spicy foods?

Answer 11

capsaicin

Question 12

what does capsaicin activate?

Answer 12

TRPV1 receptor in C fibre terminals

Question 13

what temperature does capsaicin activate at?

Answer 13

43 degrees

Question 14

what temperature activates TRPV2 receptor?

Answer 14

52 degrees

Question 15

what are histamine, serotonin, and bradykinin examples of?

Answer 15

algogenic substances

Question 16

what do algogenic substances do?

Answer 16

activate/ sensitise nociceptive nerve endings

Question 17

what happens to the AP in antidromic conditions?

Answer 17

it goes back up the nerve branch due to inactivated Na channels at the nerve junction

Question 18

what causes the release of substance P at nerve endings?

Answer 18

axon reflexes

Question 19

What presents in fine peripheral fibres and causes vasodilation, increase in vascular permeability and mast cell degranulation?

Answer 19

substance P

Question 20

what does substance P release that causes more sensitisation?

Answer 20

histamine

Question 21

what is the exaggerated response to a noxious/ nociceptive stimulus?

Answer 21

hyperalgesia

Question 22

what is it called having pain from something that would not normally produce pain?

Answer 22

allodynia

Question 23

what fibres does dental pulp contain?

Answer 23

Adelta
Abeta
C fibres

Question 24

what are the 4 layers of pulp?

Answer 24

pulp core
cell rich zone
cell free zone
odontoblast layer

Question 25

in pulpal pain, what sensitises neurones?

Answer 25

inflammatory mediators - substance P

Question 26

in pulpal pain, what nociceptors are activated?

Answer 26

TRP1
P2X3

Question 27

What are the 3 theories of dentinal sensitivty?

Answer 27

dentine innervation
hydrodynamic
odontoblast receptor

Question 28

where can signals be modified?

Answer 28

second synapse

Question 29

what do excitatory neurotransmitters do?

Answer 29

bring AP closer to threshold

Question 30

what do inhibitory neurotransmitters so?

Answer 30

makes post-synaptic nerve further away from threshold

Question 31

why is dental pain difficult to localise?

Answer 31

single axon supplies more than one tooth

Question 32

what is pain received from a location other than the site of the painful stimulus?

Answer 32

referred pain

Question 33

what triggers the gate-control theory?

Answer 33

rubbing painful area