Pain

Question 1

chronic pain is considered to be pain persisting for what duration of time?

Answer 1

more than 3 months

Question 2

In the pathway of nociception, most nociceptor cell bodies for somatic and visceral sensation are located in the [….], however those for migraine & tooth jaw pain are located in the [….]

Answer 2

dorsal root ganglion

trigeminal root ganglion

Question 3

nociceptors are specialized somatosensory because they have [….] nerve endings. Stimuli are sensed via [….] and A{beta/sigma) fibres.

Answer 3

free

C-fibres

Question 4

C-fibres are very thin, and [….] causing them to transmit very slowly. A{beta/sigma) fibres are less slightly thicker than C-fibres but are […..] allowing for very quick transmission.

Answer 4

unmyelinated

myelinated

Question 5

type IIA fibres are suited to convey information related to [….] pain, wheres C fibres are suited to convey information about […] pain. A mix of Type IIA and C fibres tend to be found in […] skin, where type C fibres only would be found in [….] type skin.

Answer 5

sharp

slow, burning

hairy (ie. back of the hand

glabrous (ie. palm of the hand)

Question 6

In terms of first and second pain, which fibres are suited to each phase?

Answer 6

C-fibres are second pain (dull, continuous throbbing)

A-fibres are first pain (sharp, intense localized)

Question 7

in nociceptive pain the intensity of the signal is [….] to the intensity of the stimulus. It is [adaptive], in that it protects by signalling potential tissue damage.

Answer 7

proportional

adaptive

Question 8

inflammatory pain, caused by inflammatory mediators and tissue damage, has special receptors catered to […..] with the aim of reducing damage and promoting recovery.

Answer 8

adaptive, low threshold pain

Question 9

[…..] is a nociceptive transducer for noxious stimuli (pH, heat, reactive chemicals, environmental cold, and cold hyperalgesia).

Answer 9

TRPV (transient receptor potential channel V)

Question 10

[…..] describes a painful response to a normally innocuous stimulus

Answer 10

allodynia

Question 11

[…]describes an increased response to normally painful stimulus

Answer 11

hyperalgesia

Question 12

projections of sensory terminals run up and down the spine, not just to the cortex, this causes enlargement of the area that feels painful well beyond the site of injury—> this is called [….]

Answer 12

secondary hyperalgesia

Question 13

maladaptive pain may stem from either

1) [….], where there is a neural lesion present causing positive and negative symptoms (peripheral and CNS dysfunction)
2) […..] where there is typically no lesion, no inflammation, and positive symptoms (CNS dysfunction)

Answer 13

neuropathic pain

dysfunctional pain

both produce maladaptive, low threshold pain

Question 14

[…..] may be caused by a PNS lesion or disease (nerve trauma, peripheral and toxic neuropathies, herpes zoster, aids) producing amplification of pain persisting independant of the lesion/disease

Answer 14

peripheral amplification

Question 15

which cortical areas are involved in the psychological modulation of pain?

Answer 15

ACC (anterior cingulate), PFC (pre-frontal), and Insula

Question 16

mechanism of top down modulation of pain?

Answer 16

ACC and PFC signal the PAG (periaqueductal gray nucleus)
PAG is also stimulated by the insula.

PAG signals down to RVM (rostral ventromedial medulla)———–>which modulates a pain transmission neuron in the spinal cord

Question 17

the signals the body sends from an injury site are termed [..]. These signals only becomes experienced as pain when they reach the [….] and the person interprets them as pain. That experience is influenced by many factors including, […..]

Answer 17

nociceptive signalling.

conscious brain/cortex

past experience, belief, and the situation.

Question 18

T/F: a withdrawal reflex may results in response to a noxious stimulus even in absence of “pain”.

Answer 18

TRUE