mechanosensation and pain

Question 1

what are the five types of touch receptors

Answer 1

pacinian copuscle
meissners corpuscle
merkels disc
ruffinis ending
free nerve ending

Question 2

what type of touch receptor is with various touch and pressure and pain and temp

Answer 2

free nerve endings

epedermis

Question 3

type of touch receptor for steady pressure, texture, slow adapting

Answer 3

merkels disc
epedermis

small and sharp borders

Question 4

type of receptor for stroking and flutter and is rapid

Answer 4

meissners corpuscle

dermis

Question 5

type of receptor for vibration, and pressure and is rapid adapting

Answer 5

pacinian or lamellated copuscle

hypodermis

large and vague borders

Question 6

type of receptor for stretch and is slow adapting

Answer 6

ruffinis ending

hypodermis

large and vague borders

Question 7

what type of fibre is the pacinian corpuscle

Answer 7

Aa or AB fibre

Question 8

pain

Answer 8

unpleasant sensory and emotional experience associated with or resembling that associated with actual or potential tissue damage

Question 9

pain

Answer 9

unpleasant sensory and emotional experience associated with or resembling that associated with actual or potential tissue damagep

Question 10

purpose of pain

Answer 10

protectice mech bring conscious awareness that tissue damage is occuring or about to occur

Question 11

congenital analgesia

Answer 11

not feeling pain

Question 12

mechanical receptors

Answer 12

respond to mechanical damage such as cutting, crushing, and pinching

Question 13

thermal receptors

Answer 13

temp extremes

Question 14

polymodal receptors

Answer 14

damaging stimuli

Question 15

do nociceptors adapt

Answer 15

no

Question 16

can nociceptors be sensitized

Answer 16

yes

peripheral: by prostaglandins (PGs)- enhance the receptor response to noxious stimuli

central; by NMDA receptor mediated long term potentiation

hyperalgesia and allodynia

Question 17

what does aspirin and other NSAIDs do

Answer 17

inhibit synthesis of PGs- analgesic effect

Question 18

fast pain

Answer 18

initial perception as brief, sharp sensation easily localized and originates from specific mechanical or thermal receptors followed by slow pain

Question 19

slow pain

Answer 19

throbbing poorly localized and persistant feeling

contributes to the inflammatory respnse to tissue injury

perstance of chemicals leads to long lasting pain that coninues after removal of mechanical or thermal stimulus

Question 20

what activates the slow pain pathway

Answer 20

chemicals like bradykinin or other PGs

Question 21

PG

Answer 21

prostaglandins

Question 22

what provokes pain

Answer 22

stimulating polymodal receptors

Question 23

two afferent fibres that transmit pain to CNS

Answer 23

Ag and C fibres

Question 24

Ag fibres

Answer 24

myelinated, medium sized, fast. cold, warmth, mechanical

Question 25

C fibres

Answer 25

unmyelinated, smallest and slowest. heat, cold, mechanical

Question 25

C fibres

Answer 25

unmyelinated, smallest and slowest. heat, cold, mechanical

Question 26

Aa and AB fibres

Answer 26

myelinated and large

proprioception, light touch

Question 27

pain neurotransmitters

Answer 27

substance P
Glutamate

Question 28

substance p

Answer 28

activates ascending pathways that transmit nocicpetive signals to higher levels for further processing

Question 29

glutamate

Answer 29

major excitatory neurotransmitter

binding to AMPA receptors leads to AP in dorsal horn neurons (sensitizing)

binding to NMDA receptrs inc ca entry and activates second messenger systems that make neurons more excitable. contributes to hypersenitivity and hyperlgesia in injured area

Question 30

can chronic pain and pain sensitization occur in the absence of injury

Answer 30

yes

Question 31

sensitization

Answer 31

pain percieved due to abnormal signallingn

Question 32

hyperalgesia

Answer 32

lowered threshold to thermal or mech stimualtion- induced pain at the injured site (primary hyperalgesia)

Question 33

allodynia

Answer 33

innocuous stimuli- touch- can result in a painful sensation due to sensitization of adjascent uninjured tissue (2nd hyperalgesia)

Question 34

what is the main component for sensitizing procedure of the nociceptors

Answer 34

PG

Question 35

what does glutumate process like

Answer 35

LTP- wind up- long term changes in synaptic transmission

Question 36

what does the built in pain suppressing system involve

Answer 36

Periacqueductral grey matter- PAG- and reticular formation- stimulation of those leads to profound analgesia and blocks substance P release from afferent nerve termials (presynaptic inhibition)

Question 37

endogenous opiates

Answer 37

endorphines, enkaphalins, dynorphin (runners high)

Question 38

what does the pain descending system depend on

Answer 38

presence of opiate receptors released from the terminals of descending alalgesic pathway

opiates bind to opate receptrs on the presynaptic terminal of the primary sensory afferent which blocks further transmission of pain signal by presynaptic inhibition

Question 39

tactile stimulation example

Answer 39

rubbing bumped elbow lessens pain

Question 40

pain perception cognitive system

Answer 40

no pain, mild, excrutiating goes back to spinal chord processing

Question 41

pain preception motivational affective system

Answer 41

tiring, fearful

Question 42

pain perception sensory discriminative system

Answer 42

throbbing, shooting