Neurobiology of Pain

Question 1

The two nerve fiber types associated with pain are

Answer 1

Type a-delta and Type C

Question 2

Continue to respond at same rate even at higher temps

Answer 2

Nonnociceptive Thermoreceptors

Question 3

Respond at higher temperatures only

Answer 3

Nociceptors

Question 4

Has two temporal elements. A sharp (first) pain, and a second (dull) pain. Which nerve fibers carry:

1. ) Sharp (first) pain
2. ) Dull (second) pain

Answer 4

1. ) Type a-delta

2. ) Type C

Question 5

Block sodium channels to prevent conduction of impulses along C fibers

Answer 5

Local Anesthetics

Question 6

What are the four components of pain?

Answer 6

1. ) Sensory discriminative component
2. ) Affective motivational component
3. ) Sensitization
4. ) Descending control/central modulation

Question 7

Tells us the location, intensity and quality of noxious stimulation

Answer 7

Sensory discriminative component

Question 8

Depends on pathways that target traditional somatosensory areas of cortex

Answer 8

Sensory discriminative component

Question 9

Tells us the unpleasant quality of the experience and activates the autonomic (fight or flight) reaction

Answer 9

Affective motivational component

Question 10

Depends on additional cortical and brainstem pathways

Answer 10

Affective motivational component

Question 11

Hypersensitivity to protect injured area, promote healing and prevent infection

Answer 11

Sensitization Component

Question 12

Functions to reduce pain perception

Answer 12

Descending control/Central modulation component

Question 13

What are the three anterolateral pathways that transmit nociceptive information?

Answer 13

Spinothalamic tract, spinorectal tract, and spinomesencephalic tract

Question 14

Tells us the discriminative aspects of pain and temperature

Answer 14

Spinothalamic Tract

Question 15

Tells us the emotional and arousal aspects of pain

Answer 15

Spinoreticular Tract

Question 16

Tells us the central modulation of pain

Answer 16

Spinomesencephalic Tract

Question 17

What are the three components of the Spinoreticular tract?

Answer 17

Amygdala, Hypothalamus, and Reticular Formation

Question 18

What are the two components of the spinomesencephalic tract?

Answer 18

Periaqueductal gray matter and superior colliculus

Question 19

Spinoreticular and spinomesencephalic tracts relay to the

Answer 19

Midline thalamic and intralaminar nuclei

Question 20

Localization of gray matter decreases in

Answer 20

Chronic pain

Question 21

A lesion of the parietal lobe or primary sensory cortex causes

Answer 21

Contralateral numb tingling or pain

Question 22

A lesion of the thalamus causes

Answer 22

Contralateral burning pain (Dejerine-Roussy Syndrome)

Question 23

A lesion of the DCMLS causes

Answer 23

Tingling, numb sensation and a tight band-like sensation around the trunk or limbs

Question 24

The feeling of having gauze on fingers is a sign of a lesion of the

Answer 24

DCMLS

Question 25

A DCMLS lesion can result in an electricity sensation down the back and extremities upon neck flexion. This is called

Answer 25

Lhermitte's sign

Question 26

Radicular pain with numbness and tingling in dermatomal distribution (radiculopathy) is a lesion of

Answer 26

Nerve roots

Question 27

Recessive mutation in sodium channels causing loss of function lead to

Answer 27

Congenital Insensitivity to Pain (CIP)

Question 28

Dormant mutations of sodium channels resulting in gain of function cause

Answer 28

Inherited Erythromelaglia (IEM) and Paroxysmal Extreme Pain Disorder (PEPD)

Question 29

Following repeated application of noxious stimuli, neighboring nociceptors that were not responsive now become responsive. This is called

Answer 29

Sensitization

Question 30

The phenomenon of stimuli that are normally perceived as slightly painful as significantly more painful

Answer 30

Hyperalgesia

Question 31

The induction of pain by what is normally an innocuous stimulus

Answer 31

Allodynia

Question 32

Results from changes in sensitivity of peripheral nociceptive receptors and/or central targets -Protects injured area, promotes healing and prevents infection

Answer 32

Sensitization

Question 33

The interaction of nociceptors with the "inflammatory soup" of substances to decrease threshold of activation for nociceptors

Answer 33

Peripheral Sensitization

Question 34

Increase response of nociceptive fibers

Answer 34

Prostaglandins

Question 35

Non-steroidal Anti-inflammatory Drugs (NSAIDS) inhibit -Prevents synthesis of prostaglandins

Answer 35

Cyclooxegenase (COX)

Question 36

Found in C fibers and are activated by moderate heat (45C) and capsaicin

Answer 36

Vanilloid receptor (VR1) / transient receptor potential (TRPV1) channels

Question 37

Repeated application causes desensitization of C fibers and also depletes Substance P to block peripheral sensitization

Answer 37

Capsaicin

Question 38

An immediate, activity dependent increase in the excitability of neurons in the dorsal horn of the spinal cord following high levels of activity in the nociceptive afferents to increase pain sensitivity

Answer 38

Central Sensitization

Question 39

Transcription independent (windup) lasts only during stimulation

Answer 39

Acute central sensitization

Question 40

Transcription dependent (allodynia) outlast stimulus for hours and can be mediated by COX

Answer 40

Chronic Central Sensitization

Question 41

Reduction in threshold for activation by peripheral stimuli

Answer 41

Chronic Central Sensitization

Question 42

Chronic Central Sensitization causes the expansion of

Answer 42

Receptive field size

Question 43

What are the two forms of descending control of pain perception?

Answer 43

Stress-induced analgesia and the placebo affect

Question 44

Effects can be blocked by naloxone, an inhibitor of opiate receptors

Answer 44

Placebo pain response

Question 45

The theory that pain results from the balance of activity in nociceptive and non-nociceptive afferents

Answer 45

Gate theory of Pain

Question 46

Purposeful lesion in the lateral funiculus from dentate ligament to line of ventral rootlets several segments rostral to highest dermatomal level of pain

Answer 46

Cordotomy for Cutaneous pain

Question 47

Visceral pain is also conveyed centrally by neurons that carry -Called referred pain

Answer 47

Cutaneous pain