Pain 2

Question 1

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

Answer 1

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

Question 2

Wha is transduction?

Answer 2

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

Question 3

What is Transmission?

Answer 3

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

Question 4

What is pain Modulation?

Answer 4

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.

Question 5

What is pain perception?

Answer 5

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

Question 6

What is the aetiology of nociceptive pain?

Answer 6

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

Question 7

What are the types of tissue involved with nociception?

Answer 7

Somatic:

• skin
• muscle
• bone

Visceral

• Thoracoabdominal
• Pelvic organs

Question 8

What is neuropathic pain?

Answer 8

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

Question 9

What are the types of stimuli for nociceptive pain?

Answer 9

Pressure

temperature

chemical

Question 10

In a nociceptive chemical stimuli what substances activate PAN?

Answer 10

Causes AP and secondary Hyperalgesia

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

Question 11

In a nociceptive chemical stimuli what substances sensitize PAN?

Answer 11

Cause allodynia, primary hyperalgesia

• leukotines
• prostaglandins
• Substance P

Question 12

In a neuropathic chemical stimuli, what substances activate PAN?

Answer 12

Cause Secondary hyperalgesia

• Norepinephrine

Question 13

In a neuropathic chemical stimuli, what substances sensitize PAN?

Answer 13

Causes allodinya and primary hyperalgesia

• Prostaglandins
• Substance P

Question 14

What substances Facilitate transduction?

Answer 14

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

Question 15

What substances Inhibit transduction?

Answer 15

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

Question 16

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

Answer 16

• ADelta fast highly myelinated
• C slow, no myelination

Question 17

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

Answer 17

Excitatory interneurons

inhibitory interneurons

projection cells

Question 18

What is a possible expalnationn for refered pain?

Answer 18

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.

Question 19

What are the pain inhibitors at the dorsal horn?

Answer 19

Chemicals

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

Behaviour

• Massage
• Counterstrain
• TENS

Descending tracts

• Serotonin & norephinephrine (antidepresants)
• opoids

Question 20

What are the pain facilitators at the dorsal horn?

Answer 20

chemical

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

Question 21

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

Answer 21

• Cortex
• Thalamus
• Reticular activating system

Question 22

What is the descending endogenous pain control mechanism?

Answer 22

• Periacueductal Gray (PAG)
• Opioids

Question 23

What are the sensory pain elements in pain perception?`

Answer 23

Pattern

area

intensity

Nature of stimuli

Question 24

What type of fibres enervate muscles

Answer 24

Afferent groups II, III, IV

Question 25

WHat type of stimulus activates a joint

Answer 25

mechanical by stretching joint to end range

Question 26

what type of stimulus activates a muscle

Answer 26

ischamia and pressure

Question 27

what type of nociceptor fibres innervate the viscera

Answer 27

A-delta and C fibres polymodal respond to mechanical heat and chemical stimuli

Question 28

How do silent nociceptors get activated?

Answer 28

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

Question 29

What is neurogenic inflamation?

Answer 29

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

Question 30

What are neuropeptides?

Answer 30

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

Question 31

What are the inflammatory mediator substances?

Answer 31

serotonin, bradykinin, prostaglandins, cytokines, and chemokines.

Question 32

What are the 3 pathways that control the level of perceived pain?

Answer 32

ascending nociceptive pathways, descending facilitatory pathways, descending inhibitory pathways.

Question 33

What type of stimuli are carried via the spinothalamic tract?

Answer 33

thermal and mechanical

Question 34

where does the STT originate?

Answer 34

primarily in laminae I and V (this can vary), with most of them crossing the midline to ascend in the contralateral anterolateral funiculus.

Question 35

Where do the spinomesencephalic tracts originate and project?

Answer 35

aminae I, IV, and V (this can vary) and send projections to the midbrain, particularly the PAG, and the nucleus cuneiformis.

Question 36

What is the role of the thealamus in pain perception

Answer 36

the thalamus in humans can produce pain sensations, and thalamic neurons in humans respond to noxious thermal or mechanical stimuli.

Question 37

What are the regions in the brain activated by painful stimulus?

Answer 37

S1 and S2, ACC, and insular cortex, prefrontal cortex, thalamus, and cerebellum15,16.

Question 38

What is the function of the primary and secondary somatosensory cortices of the brain

Answer 38

discrimination and localisation of a painful stimulus

Question 39

What part of the brain process the motivational - affective component related to pain?

Answer 39

The anterior insular and cingulate cortices mediate the unpleasantness of pain (i.e., the motivational–affective component of pain).

Question 40

Where does the brain first perceive pain and what ?

Answer 40

thalamus and sensory cortex it perceives localises describes pain

Question 41

Where is diffuse pain felt?

Answer 41

thalamus, brainstem and reticular formation

Question 42

What does the reticular formation and limbic system do?

Answer 42

ontrol the emotional and affective response to pain Because the cortex, thalamus and brainstem are interconnected with the hypothalamus and autonomic nervous system, perception of pain is associated with an autonomic response