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C H A P T E R 7
Understanding and Managing Pain
Lecture Outline
I. Pain and the Nervous System
All sensory stimulation, including pain, starts with activation of sensory neurons and
proceeds with the relay of neural impulses toward the brain.
A. Somatosensory System
The somatosensory system conveys sensory information from the body through
the spinal cord to the brain.
1. Afferent Neurons
Afferent (sensory) neurons convey sensory information from sense organs to
2. Involvement in Pain
Nociceptors are neurons capable of sensing pain stimuli. Three different types
of neurons are involved with transmitting pain impulses. The large A-beta fibers
and smaller A-delta fibers are covered with myelin, which speeds neural
transmission. The smaller and more common C fibers require high levels of
stimulation to fire. These different fibers with their different thresholds and
transmission speeds may relate to different types of pain sensation.
B. The Spinal Cord
Primary afferents from the skin enter the spinal cord where they synapse with
C. The Brain
The thalamus receives sensory input from the different neural tracts in the spinal
D. Neurotransmitters and Pain
The neurotransmitters that form the basis for neural transmission also play a role
in pain perception. The discovery of the endogenous opiates—enkephalin,
endorphin, and dynorphin—led to the discovery of neural receptors specialized for
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these neurotransmitters and the conclusion that opiate drugs produce analgesia
because of the brain’s own chemistry. The neurotransmitters glutamate and substance
P and the chemicals bradykinin and prostaglandins may exacerbate pain stimulation.
Proinflammatory cytokines produced by the immune system are also involved in pain,
possibly creating chronic pain by sensitizing neurons in the spinal cord.
E. Modulation of Pain
When the periaqueductal gray, a structure in the midbrain, is stimulated, pain
relief occurs. The neurons in the periaqueductal gray synapse with neurons in the
nucleus raphé magnus, a structure in the medulla (see Figure 7.3). These neurons
descend to the spinal cord and may constitute a descending control system for pain
perception.
II. The Meaning of Pain
The traditional view of pain focused on the physical sensations, but about 100 years
ago, C. A. Strong proposed that pain consists of not only the sensation but also person’s
reaction to that sensation.
A. Definition of Pain
Perhaps the most acceptable definition of pain is the one proposed by the
International Association Subcommittee for the Study of Pain that defined pain as an
unpleasant sensory experience accompanied by an emotional experience and actual or
potential tissue damage.
At least three stages of pain have been identified. Acute pain is ordinarily
C. Theories of Pain
How people experience pain is the subject of a number of theories. Of the several
models of pain, two capture the divergent ways of conceptualizing pain: the
specificity theory and the gate control theory.
1. Specificity Theory
The specificity theory can be traced to Descartes, who hypothesized that the
2. The Gate Control Theory
Melzack and Wall formulated the gate control theory of pain as a way to
explain the variability of pain perception (see Figure 7.4). They hypothesized that
a gating mechanism exists in the spinal cord and that sensory input is modulated
in the substantia gelatinosa of the dorsal horns of the spinal cord. This modulation
can change pain perception, as can brain-level alterations from a hypothesized
central control trigger. This theory includes explanations of both physiological
and psychological modulations of the pain experience. Melzack has proposed an
extension to the gate control theory, called neuromatrix theory, which places a
stronger emphasis on the brain’s role in pain perception.
III. The Measurement of Pain
Tools for measuring pain are important in order to evaluate the various pain
therapies. A number of techniques have been used to measure laboratory and clinical
pain, and these fall into three main categories: self-reports, behavioral assessments, and
physiological measures.
A. Self-Reports
Self-reports of pain include simple rating scales, standardized pain inventories,
and standardized personality inventories.
1. Rating Scales
With self-report rating scales, patients rate the intensity of their pain on a
scale; for example, the scale may range from 1 to 100. A similar technique is the
Visual Analog in which patients check severity of pain on a continuum from no
2. Pain Questionnaires
Melzack developed the McGill Pain Questionnaire (MPQ), an inventory that
categorized pain into three dimensions: sensory, affective, and evaluative. The
sensory dimension includes pain described in terms of its temporal, spatial,
3. Standardized Psychological Tests
Standardized tests, such as the MMPI-2, have also been used to assess pain.
This instrument is useful in differentiating among types of pain patients and has
some ability to predict which patients will respond to medical treatments for pain.
Other commonly administered tests include the Beck Depression Inventory and
the Symptom Checklist-90.
B. Behavioral Assessment
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IV. Pain Syndromes
Acute pain has the advantage of signaling injury, but chronic pain has no
advantages. Such pain can be classified according to location or syndrome, symptoms
that occur together and characterize a condition. Headache and low back pain are the two
most frequently treated types of chronic pain, but health psychologists also deal with
other pain syndromes.
A. Headache Pain
Headache pain is the most common of all pains, with more than 99% of
Americans suffering from some form of headache over their lifetime. The most
common varieties are migraine, tension, and cluster headaches, although the
B. Low Back Pain
The most frequent causes of low back pain are injury or stress resulting in
musculoskeletal, ligament, or neurological problems in the lower back. In addition,
stress and psychological factors may play roles in back pain. Most of the people who
experience back pain do not progress to chronic pain, but those who do tend to have
persistent pain. Only about 20% of back pain patients have an identified, physical
cause for their pain.
C. Arthritis Pain
A variety of arthritic pains exist, and many involve inflammation of the joints.
Rheumatoid arthritis, perhaps the most frequent cause of arthritic pain, is an
D. Cancer Pain
Understanding and Managing Pain
V. Managing Pain
Managing chronic pain is a challenge because this type of pain has no identifiable
cause. Thus, several approaches to treatment exist, including medical and behavioral
techniques.
A. Medical Approaches to Managing Pain
Treatment of acute pain is easier than for chronic pain, but both present
challenges.
1. Drugs
Analgesic drugs are the most common treatment for acute pain. These drugs
fall into two groups: opiates and nonnarcotic analgesics. Opiate drugs have
powerful analgesic effects but also produce tolerance and dependence. However,
2. Surgery
Surgery may be directed either to repairing damage that causes pain or to altering
the nervous system to change pain perception. Surgery is an attempt to control low
back pain more often than other pain syndromes, and specific nerves or the spinal
cord may be targets. Surgery may also be used to implant devices to stimulate the
spinal cord to decrease pain. Surgery is not always effective, either in repairing
damage or in producing pain relief, especially for people with low back pain. A
related technique is transcutaneous electrical nerve stimulation (TENS), which
uses electrical impulses to stimulate skin stimulation to block pain messages. Spinal
cord stimulation is more effective than TENS.
B. Behavioral Interventions for Managing Pain
Some people classify behavioral techniques as alternative treatment or mind-body
medicine, but psychologists focus on the behavioral aspects of these treatments and
consider them part of psychology.
1. Relaxation Training
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Progressive muscle relaxation involves learning to relax the entire body, one
muscle group at a time, and to breathe deeply and exhale slowly. This technique
had been used to manage a variety of pain problems, including headaches,
rheumatoid arthritis, and low back pain. A National Institutes of Health
Technology panel’s evaluation for pain treatments gave relaxation training its
highest rating.
2. Behavioral Therapy
Behavior modification techniques are based on the principles of operant
conditioning and are used by health psychologists to help people cope with stress
and pain. The goal of behavior modification is to shape behavior, not to alleviate
feelings of stress or sensations of pain. People in pain may continue their pain
behaviors because they receive positive reinforcers such as attention, sympathy,
financial compensation, relief from work, and other rewards. Positive reinforcers
Cognitive behavioral therapy aims to develop beliefs, thoughts, and skills to
make positive changes in behavior. Dennis Turk and Donald Meichenbaum have
developed a cognitive behavioral program for pain management called pain
inoculation, which parallels stress inoculation (described in Chapter 5). These
techniques involve the cognitive stage of reconceptualization and the behavioral
stages of acquisition and rehearsal of skills and follow-through.
Research indicates that behavior modification, cognitive therapy, and
cognitive behavioral therapy are effective for a wide variety of pain conditions
(see Table 7.2).
Exploring Health on the Web
Several websites provide information about many aspects of pain, including types of
pain, theories, syndromes, and treatment options.
Understanding and Managing Pain
This website is maintained by the American Chronic Pain Association, an
organization devoted to raising awareness and offering support to those with chronic pain
problems.
Suggested Activities
Personal Health Profile — Charting Pain
As an activity for their Personal Health Profile, your students should begin a pain
diary, which will supplement the stress diary they began with Chapter 6. This diary should
extend for at least a week, during which time everyone will experience some type of pain.
Creating Chronic Pain
Many factors contribute to the development of chronic pain, and social learning
theory holds that reinforcement for pain behaviors is a major contributor. To develop a
better understanding of how people reinforce pain, arrange a role-playing activity for your
students. Choose someone to be the person in pain and work with this person so that he or
she can display a realistic variety of pain behaviors. Choose others to play the roles of
family members and friends and decide who will reinforce and who will fail to reinforce the
person’s pain. (Make sure that someone ignores the person’s pain behaviors without being
mean or unkind to this person.)
Understanding the Impact of Chronic Pain
The common experience of acute pain does not lead to an understanding of chronic
pain. People who do not experience chronic pain have little understanding of what life is
like with everyday pain. To better comprehend life with chronic pain, arrange for your
students to interview someone who has a chronic pain syndrome. Instruct them to ask
questions about the person’s sensations; what barriers pain has imposed on his or her life,
what treatments the person has sought, and which treatments were more effective.
Exploring a Neurological View of Pain
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Physicians often have views that differ from those of psychologists, and you can
allow your students to become acquainted with these differences by inviting a neurologist to
be a guest lecturer on the topic of pain. A neurologist who specializes in pain treatment
would be ideal, but any neurologist should be very familiar with the puzzles of pain and its
treatment.
Describing Pain
The textbook chapter highlights a number of different pain measures. Here are
links to some of the pain measures mentioned:
Living with No Pain
Living without pain might seem like a blessing, but it is not always. Students will
Relaxation Training
One behavioral technique for managing pain is relaxation training. Below are two
sample scripts you could read aloud to students to have them gain a better understanding
Video Recommendations
From Films for the Humanities & Sciences:
Pain: The Language of the Body and the Mind (2000) is a 3-part series of short videos. This
series includes “The Physiology of Pain,” featuring the neurology underlying pain
perception and how the nervous system can modulate these signals, “The Psychology of
Pain,” which shows how emotion and behavioral factors can increase or decrease pain, and
“The Management of Pain,” which examines medical and behavioral treatments.
Understanding and Managing Pain
The Anatomy of Pain (2003) presents various types of pain, outlines how pain is
conveyed through the nervous system, distinguishes between acute and chronic pain, and
addresses treatment through medication and acupuncture.
Chronic Pain (2005) explores causes and treatments for pain by presenting pain experts
and patients who have used a variety of approaches to manage pain.
World of Pain: Coping and Caring (2001) combines dramatization and information to show
a hypothetical family and real case studies of pain. Both pain perception and pain
management are featured.
Headache: The Painful Truth (2001) explores tension, migraine, and cluster headaches and
those who suffer from them. In addition, this video includes prominent experts who present
research and findings about this pain syndrome.
Migraines (2007) focuses on this common and debilitating type of headache, including
diagnosis and treatment.
Low Back Pain (2005) explores this pain syndrome that as many as 80 percent of people
experience at some point in their lives. This program focuses on the physical injuries that
can result in back pain and the medical treatments.
From Fanlight Productions:
A Disease Called Pain (2003) explores chronic pain through the experience of chronic
pain patients. This program clearly distinguishes between acute and chronic pain and
presents some of the approaches to managing chronic pain.
Other Films:
127 Hours –A major motion movie about Aron Ralston (played by James Franco) who
needed to cut off his arm to save his life. Available for DVD rental.
Videos from the Web:
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Multiple Choice Questions
1. The ______ system allows us to interpret certain sensory information as pain.
a. somatosensory
b. endocrine
c. skeletal
d. muscular
2. Primary afferents convey sensory impulses to the
a. spinal cord.
b. peripheral nervous system.
c. brain.
d. motor neurons.
3. Myelinated afferent neurons are called
a. A fibers.
b. beta afferents.
c. C fibers.
d. delta afferents.
4. More than half of all sensory afferents are
a. A-beta fibers.
b. A-delta fibers.
c. C fibers.
d. myelinated.
5. Sherman stubbed his toe on the sidewalk. His sensation of pain traveled first to
the
a. muscles in the foot.
b. brain.
c. spinal cord.
d. cranial nerves.
6. This system conveys sensory information from the body to the brain.
a. endocrine system
b. digestive system
c. somatosensory system
d. immune system
7. _________ neurons carry nerve impulses away from the brain and toward the
muscles.
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a. Efferent
b. Afferent
c. Beta afferents
d. Delta afferents
8. Nociception refers to the process of perceiving ________.
a. stress
b. pain
c. anger
d. oxygen
9. Stimulation of the A-delta fibers, since they are myelinated, leads to a _______,
whereas the unmyelinated C fibers often result in _____________.
a. “slow pain” response; “fast pain” response
b. “no pain” response; “slow pain” response
c. “fast pain” response; “slow pain” response
d. “no pain” response; “fast pain” response
10. Afferent fibers group together after leaving the skin, forming a _____.
a. nerve
b. cell
c. cell body
d. ganglion cell
11. When pain is experienced in some other location than the site where the pain was
inflicted, this is called
a. phantom limb pain.
b. referred pain.
c. prechronic pain.
d. chronic recurrent pain.
12. Recent research gave participants __________ to reduce people’s feelings of
social pain.
a. a shock
b. a hug
c. Tylenol
d. Morphine
13. Participants who are socially excluded show more activity in the anterior
cingulate cortex, similar to people who are experiencing _____________.
a. physical pain
b. depression
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c. anxiety
d. all of the above
14. _____ are chemicals that carry information between nerves.
a. Afferent neurons
b. Efferent neurons
c. Neurotransmitters
d. Interneurons
15. _______ are neurochemicals that help modulate, or lessen, the experience of pain.
a. Endorphins
b. Interneurons
c. Glutamates
d. Proinflammatory cytokines
16. These proteins produced by the immune system increase pain sensitivity, along
with increasing fatigue and sickness:
a. proinflammatory cytokines
b. endorphins
c. opiates
d. both a and b
17. The dorsal horns are located in the
a. brain stem.
b. kidneys.
c. midbrain.
d. spinal cord.
18. The substantia gelatinosa is
a. in the dorsal horns of the spinal cord.
b. in the midbrain region, adjacent to the thalamus.
c. composed of a gelatin-like material that surrounds the lower portion of the
brain.
d. a hypothetical structure that has not yet been confirmed.
19. Which structure is most capable of modulating sensory input?
a. primary afferents
b. secondary afferents
c. substantia gelatinosa
d. spinothalamic tract
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20. Sensory input information passes through what brain structure?
a. the parietal lobe of the cerebral cortex
b. the pons
c. the cerebellum
d. the thalamus
21. What brain structure contains a representation of the skin’s surface?
a. somatosensory cortex
b. parietosensory area
c. sensorimotor cortex
d. occipital cortex
22. Neurotransmitters like _____ decrease pain, but those like ________ increase the
experience of pain.
a. serotonin . . . dynorphin
b. endorphin . . . glutamate
c. substance P . . . serotonin
d. endorphin . . . enkephalin
23. Which of the body’s own neurochemicals does NOT have opiate-like effects?
a. serotonin
b. dynorphin
c. endorphin
d. enkephalin
24. Pain is usually defined as
a. a sensory experience only.
b. an emotional experience only.
c. neither a sensory nor an emotional experience.
d. both a sensory and an emotional experience.
25. Victoria has just cut her hand with a sharp knife. The pain she feels can best be
described as
a. acute.
b. prechronic.
c. chronic intractable.
d. chronic.
26. Which of these is NOT a distinction between chronic and acute pain?
a. Acute pain is usually adaptive; chronic pain is not.
b. Acute pain is physical; chronic pain is psychological.
c. Chronic pain is frequently perpetuated by environmental reinforcers; acute
pain needs no such reinforcement.
d. Chronic pain has no biological benefit; acute warns the person to avoid
further injury.
27. Henry Beecher reported that soldiers wounded at the Anzio beachhead during
World War II experienced ______ pain.
a. chronic intractable
b. stress-related
c. severe, excruciating
d. very little
28. Kyle is experiencing headaches and his partner has taken over the household
chores. Research by Pence et al. (2008) would suggest that Kyle’s headaches are
likely to
a. increase in intensity.
b. decrease in intensity.
c. completely disappear.
d. disappear until his partner makes him do the chores again.
29. This personality trait has been associated with a “pain–resistant” personality.
a. Conscientiousness
b. Extraversion
c. Neuroticism
d. There is no “pain–resistant” personality.
30. Physicians are likely to underestimate the pain of
a. Asian Americans.
b. African Americans.
c. European Americans.
d. no ethnic group; doctors treat all patients equally.
31. According to the gate control theory, emotions such as ______ could increase
pain by affecting the gate to open, whereas emotions such as _____ could
decrease pain by affecting the gate to close.
a. happiness; depression
b. joy; anxiety
c. anxiety; happiness
d. depression; anxiety
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32. Matthew is running a marathon and trips over a pile of acorns, but finishes the
race. Afterwards, he finds out his ankle is sprained. What theory best accounts for
the fact that Matthew did not immediately stop running after tripping?
a. specificity theory of pain
b. gate control theory of pain
c. delay of gratification theory of pain
d. none of the above
33. People in pain frequently receive attention and sympathy, which may provide
____________ for these pain behaviors.
a. reinforcement
b. negative scheduling
c. punishment
d. generalization
34. In some cultures, people undergo initiation rituals that call for them to have their
body pierced, cut, tattooed, burned, or beaten. These individuals
a. feel no pain.
b. show little or no pain from an accidental injury.
c. feel pain, but their culture trains them to exhibit no pain during these
initiation rituals.
d. offer proof that pain is totally psychological.
35. What is the relationship between the experience of pain and some types of
psychopathology?
a. People with personality disorders have heightened pain perception.
b. People with pain-prone personalities tend to have borderline personality
disorder.
c. People with pain-resistant personalities tend to have bipolar disorder.
d. It is not clear whether psychopathology makes one vulnerable to pain or
whether being in pain produces psychopathology.
36. During the birth process, women in some cultures exhibit many more signs of
pain than women in other cultures. This observation shows that
a. the experience of pain varies from culture to culture.
b. cultural practices can influence the expression of pain.
c. natural childbirth produces less pain than opiate drugs.
d. women who express little pain during childbirth are undergoing self-
hypnosis.
37. With regard to gender,
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a. women sense pain more quickly than men.
b. women are more likely to hide their pain.
c. men are more likely to be aware of their pain.
d. men are less likely to report pain.
38. Specificity theory hypothesizes that
a. a person’s interpretation of pain is more important that tissue damage in
determining the intensity of pain.
b. acute pains intensify over time.
c. the experience of pain is approximately equal to the amount of tissue
damage or injury.
d. chronic pain can become acute pain over time.
39. Which of these findings cast doubt on the specificity theory of pain?
a. Researchers have failed to find specific skin receptors devoted to relaying
pain.
b. Phantom limb pain occurs in 70% of amputees.
c. Injury can occur without pain, such as that experienced by the soldiers at
Anzio beach.
d. all of these
40. The theory of pain proposed by Melzack and Wall has been called the _____
theory.
a. gate control
b. sensory decision
c. cognitive-emotional
d. tension-reduction
41. According to the gate control theory of pain, the structure that is the likely
location of the gate is
a. the substantia gelatinosa.
b. the ventral horns of the spinal cord.
c. the transverse section of the medulla.
d. supraspinal nerve endings.
42. According to the gate control theory of pain, the spinal cord
a. mechanically relays sensory input information.
b. modulates the input of sensory information.
c. does not have the physiological capacity to affect pain perception.