II-16 The Significance and Elusive Nature of Pain

Question 1

Compare the patient’s and provider’s view of pain.

Answer 1

For the provider, pain is a somewhat irrelevant by-product of whatever is causing the problem; for the patient, the pain tends to be the problem.

Question 2

Discuss the prevalence of chronic pain in the U.S.

Answer 2

Chronic pain, which is pain that lasts six months or longer, affects 30-50 million people in the U.S.

Question 3

Identify factors that influence the experience of pain.

Answer 3

• A person’s interpretation of the stimulus
• The context in which it is experienced (Sympathetic arousal in athletic competition may diminish pain sensitivity, whereas the same arousal due to stress may heighten it)
• Culture (In some cultures, pain is reported earlier and people react more intensely to it)
• Gender (Women typically show greater pain sensitivity than men)

Question 4

Name two dimensions of pain that are measured by pain questionnaires.

Answer 4

1. Quality of pain (whether it is throbbing shooting)

2. Pain intensity

Question 5

Distinguish among the three kinds of pain perception.

Answer 5

1. Mechanical nociception (pain perception) that results from mechanical damage to the tissue of the body
2. Thermal nociception (pain due to exposure to extreme heat or cold)
3. Polymodal nociception (related to chemical irritants such as capsaicin)

Question 6

Describe the pathway followed by nociceptors.

Answer 6

peripheral nervesspinal cordreticular formationthalamuscortex

Question 7

Distinguish among the two major never fibers involved in nociception.

Answer 7

• A-delta fibers are small, myelinated fibers that transmit sharp pain. They respond especially to mechanical or thermal pain, transmitting sharp brief pains rapidly.
• C-fibers are unmyelinated nerve fibers, involved in polymodal pain, that transmit dull or aching pain.

Question 8

Identify the two neurotransmitters that are implicated in pain transmission.

Answer 8

Substance P is a neuropeptide that transmits information about tissue damage to the central nervous system. Glutamate is an excitatory neurotransmitter that acts as an agent in transmitting pain signals.

Question 9

List the three families of endogenous opioid peptides.

Answer 9

1. Beta-endorphins, which produce peptides that project to the limbic system and brain stem, among other places.
2. Proenkaphalins, which are distributed throughout the nervous and endocrine systems.
3. Prodynorphins, found in the gut and the posterior pituitary.

Question 10

Cite evidence that endogenous opioid peptides are involved in stress-induced analgesia (SIA).

Answer 10

Endogenous opioid peptides are found in the adrenal glands, pituitary gland, and hypothalamus, which are are linked to stress response.

Question 11

pain behaviors

Answer 11

Behaviors that result in response to pain, such as cutting back on work or taking drugs.

Question 12

nociception

Answer 12

The perception of pain.

Question 13

endogenous opioid peptide

Answer 13

Opiate-like substances produced by the body.