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Flashcards in Pain 2 Deck (43)
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1

What are the 4 major steps involved in the nociceptive pathway?

  1. Transduction 
  2. Transmission 
  3. Modulation
  4. Perception 

 

2

Wha is transduction?

Transduction is the process of converting a mechanical, chemical, or thermal stimulus and turning it into an action potential

3

What is Transmission? 

Projection of the action potential from the periphery through the dorsal horn propagating to the CNS 

4

What is pain Modulation?  

Pain modulation is the facilitation (amplify) or inhibition of action potential occuring at any point during the transmission process.

  • Primary afferent nociceptor (PAN) releases Substance P (SP) and Glutamine (Glu) on synaptic cleft
  • Stimulation of exitatory neurotransmitters and projection cells which amplify/ inhibit PAN signal
  • Pain signal if strong enough continues to the brain.  

5

What is pain perception? 

The interpretation of the pain stimuli by the brain.

  1. Thalamus and sensory cortex: perceive, describe and localize pain 
  2. Thalamus, brainstem (BS) and reticular formation: identiffy dull (long lasting), Diffuse pain
  3. Reticular formation and limbic system: control emotional and affective response to pain. 
  4. Hypothalamus: conected to Cortex, BS, thalamus, perception of pain causes autonomic response  

6

What is the aetiology of nociceptive pain? 

The activation of primary afferent nerves with peripheral terminals that respond to noxious stimuli. 

 

  • Nocicepation may or may not be perceived as pain depending of interactions with nociceptive pathways 

7

What are the types of tissue involved with nociception? 

Somatic:

  • skin 
  • muscle
  • bone

Visceral

  • Thoracoabdominal 
  • Pelvic organs 

 

8

What is neuropathic pain? 

  • Unreleived noxious stimuli
  • damage to nerve tissue 
  • etiology of neuropathic pain 

9

What are the types of stimuli for nociceptive pain?

Pressure

temperature

chemical 

10

In a nociceptive chemical stimuli what substances activate PAN? 

Causes AP and secondary Hyperalgesia

  • K+
  • H+
  • serotonin
  • Bradykinin 
  • Histamine

11

In a nociceptive chemical stimuli what substances sensitize PAN? 

Cause allodynia, primary hyperalgesia

  • leukotines
  • prostaglandins 
  • Substance P

12

In a neuropathic chemical stimuli, what substances activate PAN?

Cause Secondary hyperalgesia

  • Norepinephrine

13

In a neuropathic chemical stimuli, what substances sensitize PAN?

 

Causes allodinya and primary hyperalgesia 

  • Prostaglandins 
  • Substance P 

14

What substances Facilitate transduction?

  • Prostaglandins
  • Leukotines
  • Histamine
  • Seratonin
  • Substance P
  • Norepinephrine 

15

What substances Inhibit transduction?

  • NSAID
  • steroids
  • antihistamines
  • capsacin 
  • anxiolytics
  • non pharma theraphy 

 

16

What are the pheripheal nerve fibres that transmit the action potential? 

  • ADelta fast highly myelinated  
  • C slow, no myelination 

17

What are the 3 types of neurons in the dorsal horn? 

Excitatory interneurons

inhibitory interneurons

projection cells

18

What is a possible expalnationn for refered pain?

Both visceral and nociceptive neurons decasate at lamina 2 in the dorsal horn, thus the body cant identify specifically where the pain signal is comming from and sends efferent neurons to the skin.  

19

What are the pain inhibitors at the dorsal horn?

 

Chemicals

  • GABA receptors
  • calcitonin
  • somatostanin
  • Alpha 2
  • NMDA receptor

Behaviour

  • Massage
  • Counterstrain 
  • TENS

Descending tracts 

  • Serotonin & norephinephrine (antidepresants)
  • opoids

20

What are the pain facilitators at the dorsal horn?

chemical

  • A delta and C fiber input
  • Substance P
  • NON- NMDA receptors

21

Where does the brain receive the signals from the ascending tracts (Spinothalamic)

  • Cortex
  • Thalamus
  • Reticular activating system 

22

What is the descending endogenous pain control mechanism? 

  • Periacueductal Gray (PAG)
  • Opioids 

23

What are the sensory pain elements in pain perception?`

Pattern 

area 

intensity 

Nature of stimuli 

24

What type of fibres enervate muscles 

Afferent groups II, III, IV

25

WHat type of stimulus activates a joint

mechanical by stretching joint to end range

26

what type of stimulus activates a muscle 

ischamia and pressure 

27

what type of nociceptor fibres innervate the viscera

A-delta and C fibres 

polymodal

respond to mechanical heat and chemical stimuli 

28

How do silent nociceptors get activated? 

fter tissue injury, they become activated and respond to noxious stimuli.

substances released as a result of the injury may sensitize the nociceptors, allowing them to fire to lower-intensity stimuli

29

What is neurogenic inflamation?

Neurogenic inflammation is a term used to describe the role of the nervous system in the development and maintenance of peripheral inflammation.

30

What are neuropeptides?

Neuropeptides such as substance P and calcitonin gene-related peptide (CGRP) are contained in small-diameter afferents (Groups III and IV).