Pain

Question 1

What are nociceptors?

Answer 1

Sensory receptors at free endings of A delta and C fibers

Question 2

What kind of noxious stimuli do nociceptors detect? Where is it sent to?

Answer 2

Mechanical, Thermal, Chemical
to the CNS

Question 3

Where are nociceptors?

Answer 3

Skin, viscera, muscles, joints

Question 4

Describe pain transmission of A delta, Gr. III?
Pain
Noxious Stimuli
Threshold
Fast or Slow
Localized or Broad

Answer 4

SHARP pain
Noxious stimuli: mechanical, thermal
Low Threshold
FAST
Localized

Question 5

Describe pain transmission of C fibers, Gr. IV?
Pain
Noxious Stimuli
Fast or Slow
Localized or Broad

Answer 5

DULL
Noxious stimuli: mechanical, thermal, chemical
High Threshold
SLOW
Broad

Question 6

Why do we feel the initial pain from (ex. pinching)?

Answer 6

A delta fibers transmits info to brain

Question 7

Why do we feel the lingering pain from (ex. pinching)?

Answer 7

C-fibers continue to transmit info to brain

Question 8

Which fibers are processed in the lateral pain system?

Answer 8

A delta, Gr. III

Question 9

Which fibers are processed in the medial pain system?

Answer 9

C-fibers

Question 10

What is sensitization?

Answer 10

Increased responsiveness OR decreased threshold of nociceptive neurons

Question 11

What is peripheral sensitization?

Answer 11

dysfunction in PNS

Question 12

What is central sensitization?

Answer 12

dysfunction in SC or brain

Question 13

What fibers are involved in peripheral sensitization?

Answer 13

A delta, C-fibers

Question 14

Which neurons are involved in central sensitization?

Answer 14

2nd or 3rd Order Neurons

Question 15

What are the three dorsal horn neurons?

Answer 15

Projection (Excitatory)
Interneurons (Inhibitory)
Wide Dynamic (Exc and Inhib)

Question 16

What are interneurons packed with that we lose during chronic disorders?

Answer 16

Opioids

Question 17

What is lateral spinothalamic tract for?

Answer 17

Sensory + Discriminative Touch (pain)

Question 18

What is anterior spinothalamic tract for?

Answer 18

Motivational-Affective Pain

Question 19

Which tract is for lateral pain system?

Answer 19

Lateral spinothalamic tract

Question 20

Which tract is for medial pain system?

Answer 20

Anterior spinothalamic tract

Question 21

What is the spinolimbic tract for?

Answer 21

Emotion, cognitive (visceral pain)

Question 22

What is the pain matrix?

Answer 22

Brain regions that process and regulate pain info

Question 23

Location of pain regulation: sensory-discrimination

Answer 23

Thalamus
Somatosensory Cortex (S1+S2)

Question 24

Location of pain regulation: Motivational-Affective pain

Answer 24

Cerebral (Insula, Cingulate, Prefrontal Cortex)
Amygdala + Hypothalamus
Thalamus (Intralaminar nuclei)

Question 25

Location of pain regulation: cognitive

Answer 25

Prefrontal Cortex (DLPFC)

Question 26

Location of pain regulation: descending control

Answer 26

Midbrain + Brainstem

Question 27

What is the main descending pain pathway?

Answer 27

PAG-RVM

Question 28

What are descending pathways full of?

Answer 28

Opioids

Question 29

What is the Gate Control Theory?

Answer 29

Opens or closes by modulating activity of DH neurons

Question 30

Factors of Gate Control Theory?

Answer 30

Amount of activity in nociceptive fibers Amount of activity in other peripheral fibers Signals from descending pain pathways

Question 31

What happens when the gate opens? (GCT)

Answer 31

Inc nociceptive activity Dec descending inhibitory pathways

Question 32

What happens when the gate closes? (GCT)

Answer 32

Inc activity of large diameter afferents Inc descending inhibitory pathways