Chapter 16: Pain, Temperature Regulation, Sleep, and Sensory Function

Pricking one's finger with a needle would cause minimal pain, whereas experiencing abdominal surgery would produce more pain. This distinction is an example of which pain theory? a. Gate control theory b. Intensity theory c. Specificity theory d. Pattern theory

ANS: C According to the specificity theory, a direct relationship exists between the intensity of pain and the extent of tissue injury. The remaining options are not related to the intensity of perceived pain.

Pain that warns of actual or impending tissue injury is referred to as what? a. Chronic b. Psychogenic c. Acute d. Phantom

ANS: C Acute pain is a protective mechanism that alerts the individual to a condition or experience that is immediately harmful to the body. The remaining options do not fulfill this objective.

The major relay station of sensory information is located in the: a. Basal ganglia b. Midbrain c. Thalamus d. Hypothalamus

ANS: C Although the organization of all of the ascending tracts is complex, the principal target for nociceptive afferents is the thalamus, which, in general, is the major relay station of sensory information. The remaining options do not fulfill this objective.

Prolonged high environmental temperatures that produce dehydration, decreased plasma volumes, hypotension, decreased cardiac output, and tachycardia cause which disorder of temperature regulation? a. Heat cramps b. Heat stroke c. Malignant hyperthermia d. Heat exhaustion

ANS: D Of the options presented, only heat exhaustion, or collapse, is a result of prolonged high core or environmental temperatures resulting in dehydration, decreased plasma volumes, hypotension, decreased cardiac output, and tachycardia.

What is a long-term complication of rewarming as a treatment for hypothermia? a. Acidosis b. Dysrhythmias c. Shock d. Renal failure

ANS: D Rewarming can result in long-term complications that include congestive heart failure, hepatic and renal failure, abnormal erythropoiesis, myocardial infarction, pancreatitis, and neurologic dysfunctions. Short-term complications of rewarming include acidosis, rewarming shock, and dysrhythmias.

Which statement is true regarding the gate control theory (GCT) of pain? a. The pain gate is located in the brain. b. A closed gate increases pain perception. c. The brain primarily controls the pain gate. d. An open gate facilitates the brain in processing the pain.

ANS: D The open gate in the spinal cord regulates the transmission of pain impulses that ascend to the brain for further processing and interpretation, thus leading to the management of pain. The remaining statements are not true when discussing the GCT of pain.

Match the types of chronic pain with its description. Types of pain may be used more than once. ______ A. Myofascial pain syndrome ______ B. Neuropathic pain ______ C. Deafferentation pain ______ D. Sympathetically maintained pain 49. Pain that results from tumor infiltration of nerve tissue, from trauma or chemical injury to the nerve, or from damage from radiation, chemotherapy, or surgical sectioning of the nerve 50. Pain that is thought to be caused by trauma or disease of nerves and leads to abnormal processing of sensory information by the peripheral and central nervous systems 51. Pain that occurs after peripheral nerve injury and is described as continuous with severe sensations and a burning quality 52. Pain that is the result of muscle spasms, tenderness, and stiffness and leads to muscle guarding that limits muscle motion

49. ANS: C MSC: Deafferentation pain results from trauma or chemical injury to the peripheral nervous system, from tumor infiltration of nerve tissue, or from damage from radiation, chemotherapy, or surgical sectioning of a nerve with the loss of sensory input to the central nervous system. 50. ANS: B MSC: Neuropathic pain is the result of trauma or disease of nerves and leads to abnormal processing of sensory information by the peripheral and central nervous systems. 51. ANS: D MSC: Sympathetically maintained pain (SMP) is another type of neuropathic pain that occurs after peripheral nerve or extremity injury and is characterized as continuous and severe with a burning quality. 52. ANS: A MSC: Myofascial pain syndrome (MPS) is associated with injury to muscle, fascia, and tendons.

The sudden apparent arousal in which a child expresses intense fear or another strong emotion while still in a sleep state characterizes which sleep disorder? a. Night terrors b. Insomnia c. Somnambulism d. Enuresis

ANS: A Three types of parasomnias include arousal disorders such as confusional arousals, sleepwalking (somnambulism), and night terrors (dream anxiety attacks). The remaining options do not involve a sense or expression of fear or any other strong emotion.

Which hormones help diminish the febrile response? a. Arginine vasopressin (AVP), melanocyte-stimulating hormone-alpha (a-MSH), and corticotropin-releasing factor b. Adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone, and thyroxine (T4) c. Antidiuretic hormone, growth hormone, and aldosterone d. None; hormones only facilitate the increase of core body temperature.

ANS: A During fever, AVP, a-MSH, and corticotropin-releasing factors are released from the brain, and antiinflammatory cytokines (e.g., IL-1, IL-10) can act as endogenous cryogens or antipyretics to help diminish the febrile response. The other options are not hormones that diminish the febrile response.

Massage therapy relieves pain by closing the pain gate with the stimulation which fibers? a. Ab(beta) b. Ad c. B d. C

ANS: A Massaging stimulates different Ab fibers to close the pain gate. The remaining options do not fulfill this objective.

Which neurotransmitters inhibit pain in the medulla and pons? a. Norepinephrine and serotonin b. Gamma-aminobutyric acid (GABA) and aspartate c. Glutamate and tumor necrosis factor-alpha d. Neurokinin A and nitric oxide

ANS: A Norepinephrine and serotonin (5-hydroxytryptamine) contribute to pain modulation (inhibition) in the medulla and pons. The remaining options do not fulfill this objective.

Loud snoring, a decrease in oxygen saturation, fragmented sleep, chronic daytime sleepiness, and fatigue are clinical manifestations of which sleep disorder? a. Obstructive sleep apnea b. Upper airway resistance syndrome c. Somnambulism d. Narcolepsy

ANS: A Obstructive sleep apnea is characterized by repetitive increases in resistance to airflow within the upper airway with loud snoring, gasping, intervals of apnea lasting from 10 to 30 seconds, fragmented sleep, and chronic daytime sleepiness and fatigue, as well as a decrease in oxygen saturation. The remaining options do not exhibit the signs and symptoms listed in the stem.

Which pain theory proposes that a balance of impulses conducted from the spinal cord to the higher centers in the central nervous system (CNS) modulates the transmission of pain? a. GCT b. Pattern theory c. Specificity theory d. Neuromatrix theory

ANS: A Only the gate control theory (GCT) explains that a balance of impulses conducted to the spinal cord, where cells in the substantia gelatinosa function as a spinal gate, regulates pain transmission to higher centers in the CNS.

What is the term that denotes the duration of time or the intensity of pain that a person will endure before outwardly responding? a. Tolerance b. Perception c. Threshold d. Dominance

ANS: A Pain tolerance is the duration of time or the intensity of pain that an individual will endure before initiating overt pain responses. The other options are not related to the duration or intensity of pain endured before the pain is recognized.

Heat loss from the body via radiation occurs by: a. Emanations of electromagnetic waves b. Transfer of heat through currents of liquids or gas c. Dilation of blood vessels bringing blood to skin surfaces d. Direct heat loss from molecule-to-molecule transfer

ANS: A Radiation refers to heat loss through electromagnetic waves. None of the other options accurately describes heat loss via radiation.

Up to how many liters of fluid per hour may be lost by sweating? a. 2 b. 4 c. 6 d. 8

ANS: A Sweating may cause as much as 2.2 L of fluid per hour to be lost.

Where in the CNS does a person's learned pain response occur? a. Cerebral cortex b. Frontal lobe c. Thalamus d. Limbic system

ANS: A The cognitive-evaluative system overlies the individual's learned behavior concerning the experience of pain and can modulate the perception of pain and is mediated only through the cerebral cortex.

What part of the brain provides the emotional response to pain? a. Limbic system b. Parietal lobe c. Thalamus d. Hypothalamus

ANS: A The limbic and reticular tracts are involved in alerting the body to danger, initiating arousal of the organism, and emotionally processing the perceived afferent signals, not just as stimuli, but also as pain. The remaining options do not fulfill this objective.

What are the expected changes in sleep patterns of older adults? a. Older adults experience difficulty falling asleep with less time spent in REM sleep. b. They experience sound sleep during the night with approximately 50% of the time spent in REM sleep and dreaming. c. Older men commonly experience interrupted sleep patterns later in life than do older women. d. Older adults awaken often but with a rapid return to sleep; they awaken refreshed but often later in the morning.

ANS: A The sleep pattern of the older adult differs from the younger adult in that total sleep time is decreased, and the older individual takes longer to initiate and maintain sleep. Older adults tend to go to sleep earlier in the evening and awaken more frequently during the night and earlier in the morning. Rapid eye movement (REM) and slow-wave sleep decreases. The alteration in sleep pattern typically appears approximately 10 years later in women than it does in men.

The gate in the GCT of pain is located in the: a. Substantia gelatinosa b. Marginal layer c. Nucleus proprius d. Dorsolateral tract of Lissauer

ANS: A The synaptic connections between the cells of the primary- and secondary-order neurons located in the substantia gelatinosa and other Rexed laminae function as a pain gate. The remaining options do not act in this function.

Based on an understanding of the physiologic process of nociceptors, the nurse expects which surgical procedure to create more pain? a. Repair of several crushed fingers b. External fixation of a dislocated shoulder c. Cyst removal on the internal surface of an ovary d. Repair of a ruptured spleen

ANS: A The variable nature and distribution of nociceptors affect the relative sensitivity to pain in different areas of the body; the tips of the fingers have more nociceptors than the skin on the back, and all skin has many more nociceptors than the internal organs including bone.

Why are children more susceptible to heat stroke than are adults? (Select all that apply.) a. Children produce more metabolic heat when exercising. b. They have more surface area-to-mass ratio. c. Children have less sweating capacity. d. They an underdeveloped hypothalamus. e. Children have an overdeveloped ability to perceive heat.

ANS: A, B, C Children are more susceptible to heat stroke than are adults because (1) they produce more metabolic heat when exercising, (2) they have a greater surface area-to-mass ratio, and (3) their sweating capacity is less than that of adults. The remaining options are not true of a child.

Heat exhaustion results in: (Select all that apply.) a. Profuse sweating b. Profound vasodilation c. A need to ingest warm liquids d. Permanent damage to the hypothalamus e. An increased risk for future heat exhaustion

ANS: A, B, C Internally high temperatures cause the appropriate hypothalamic response of profound vasodilation and profuse sweating. The individual should be encouraged to drink warm fluids to replace fluid lost through sweating. Heat exhaustion is a result of prolonged high core or environmental temperatures that are unique to each incidence.

Which factors contribute to sensorineural hearing loss? (Select all that apply.) a. Ménière disease b. Aging c. Diabetes mellitus d. Noise exposure e. Outer ear trauma

ANS: A, B, C, D Impairment of the organ of Corti or its central connections causes a sensorineural hearing loss. The hearing loss may be gradual or sudden. Conditions that commonly cause sensorineural hearing loss include congenital and hereditary factors, noise exposure, aging, Ménière disease, ototoxicity, and systemic disease (e.g., syphilis, Paget disease, collagen diseases, diabetes mellitus). Outer ear trauma is not a typical cause of sensorineural hearing loss.

It is true that a fever: (Select all that apply.) a. Is a complex cascade involving several different systems. b. Can be a result of a dysfunctional hypothalamus. c. Should be eliminated as quickly as possible. d. Triggers endocrine responses. e. Is in response to a pyrogen.

ANS: A, B, D, E Fever is a complex, integrated cascade of behavioral, neurologic, and endocrine responses to an immune challenge initiated by endogenous pyrogens or disorders of the hypothalamus. Fever production aids responses to infectious processes through several mechanisms and should be interrupted only when it might present an additional risk to the individual.

How can glaucoma cause blindness? a. Infection of the cornea b. Pressure on the optic nerve c. Opacity of the lens d. Obstruction of the venous return from the retina

ANS: B Loss of visual acuity as a result of pressure on the optic nerve is the only reason glaucoma can result in blindness.

Which description characterizes visceral pain? a. Is sharp and well-defined when transmitted by A-delta (Ad) fibers. b. Is perceived as poorly localized and is transmitted by the sympathetic nervous system. c. Arises from connective tissue, muscle, bone, or skin. d. Is perceived as dull, aching, and poorly localized when transmitted by C fibers.

ANS: B Of the options provided, only visceral pain refers to pain in internal organs and the abdomen and is transmitted by sympathetic afferents. Visceral pain is poorly localized because of fewer nociceptors in the visceral structures.

When considering the risk factors for the development of phantom limb pain, the nurse recognizes which as a primary contributing factor? a. Age, with adolescent patients being at a higher risk than adults b. Presence of pain in the limb before amputation c. Patient's previous experience with managing pain d. Cultural views regarding the acceptance of pain

ANS: B Phantom limb pain is pain that an individual feels in an amputated limb after the stump has completely healed. It is more likely to appear in individuals who experienced pain in the limb before amputation. The other options would not be considered a primary contributing factors.

Rapid eye movement (REM) sleep occurs in cycles approximately every: a. 45 minutes b. 90 minutes c. 120 minutes d. 150 minutes

ANS: B REM sleep accounts for 20% to 25% of sleep time and is characterized by desynchronized, low-voltage, fast activity that occurs for 5 to 60 minutes approximately every 90 minutes, beginning after 1 to 2 hours of non-REM sleep.

Where are the primary-order pain transmitting neurons located within the spinal cord? a. Lateral root ganglia b. Dorsal root ganglia c. Anterior root ganglia d.Medial root ganglia

ANS: B The cell bodies of the primary-order neurons, or pain-transmitting neurons, reside only in the dorsal root ganglia just lateral to the spine along the sensory pathways that penetrate the posterior part of the cord.

Which endogenous opioid is located in the hypothalamus and pituitary and is a strong m-receptor agonist? a. Enkephalins b. Endorphins c. Dynorphins d. Endomorphins

ANS: B The synthesis and activity of b-endorphin is concentrated in the hypothalamus and the pituitary gland and act as strong µ-receptor agonist. The remaining options do not fulfill this objective.

In acute hypothermia, what physiologic change shunts blood away from the colder skin to the body core in an effort to decrease heat loss? a. Hypotension b. Peripheral vasoconstriction c. Voluntary muscle movements d. Shivering

ANS: B Tissue hypothermia slows the rate of chemical reactions (tissue metabolism), increases the viscosity of the blood, slows blood flow through microcirculation, facilitates blood coagulation, and stimulates profound vasoconstriction. The remaining options do not fulfill this objective.

A heat stroke is characterized by: a. Core temperatures usually reaching approximately 39.9° C (103.9° F) b. Sweat production on the face occurring even during dehydration c. A rapidly decreasing core temperature as heat loss from the evaporation of sweat ceases d. Symptoms caused by the loss of sodium and prolonged sweating

ANS: B When the core temperature reaches or exceeds 40.5° C (104.9° F), the brain may be preferentially cooled by maximal blood flow through the veins of the head and face, specifically the forehead. Sweat production on the face is maintained even during dehydration. The remaining options do not occur during heat stroke.

The basis of the specificity theory of pain is that: a. Injury to specific organs results in specific types of pain. b. Chronic pain is generally less intense than acute pain. c. The greater the tissue injury, the greater the pain. d. Acute pain is specific only to certain injuries.

ANS: C According to the specificity theory, a direct relationship exists between the intensity of pain and the extent of tissue injury. The remaining options are not accurate statements regarding this pain theory.

When comparing the effects of acute and chronic pain on an individual, chronic pain is more often: a. The external event that results in a sense of fear b. Viewed as being meaningful but undesirable c. A factor that contributes to depression d. A sense of internal unease

ANS: C Chronic pain is often associated with a sense of hopelessness and helplessness as relief becomes more elusive and the timeframe more protracted. The pain is perceived as meaningless, and depression is often a concomitant finding, as either a result of the chronic pain state or as a contributor to its development. Individuals often psychologically respond to acute pain with fear (e.g., fear of diagnosis, fear of continued pain), anxiety, and a general sense of unpleasantness or unease.

Coronary artery disease is most affected by which component of sleep? a. Non-REM b. Light c. REM d. Delta wave

ANS: C Coronary artery disease is most affected during rapid eye movement (REM) sleep. During this component of sleep, dreams may provoke nocturnal angina, increased heart rate, and electrocardiographic (ECG) changes. The other options are not associated with coronary artery disease.

Enkephalins and endorphins act to relieve pain by which process? a. Inhibiting cells in the substantia gelatinosa b. Stimulating the descending efferent nerve fibers c. Attaching to opiate receptor sites d. Blocking transduction of nociceptors

ANS: C Enkephalins and endorphins are neurohormones that act as neurotransmitters by binding to one or more G protein-coupled opioid receptors and thus relieving pain. The other options are not accurate descriptions of how enkephalins and endorphins relieve pain.

How does the release (increase) of epinephrine raise body temperature? a. The release of epinephrine causes shivering. b. It affects muscle tone. c. It raises the metabolic rate. d. It increases and strengthens the heart rate.

ANS: C Epinephrine and norepinephrine produce a rapid transient increase in heat production by raising the body's basal metabolic rate. The other options are not correct descriptions of the effects of epinephrine on body heat.

Which type of nerve fibers transmits pain impulses? a. A-alpha (Aa) fibers b. A-beta (Ab) fibers c. A-delta (Ad) fibers d. B fibers

ANS: C Of the available options, only medium-sized Ad fibers transmit pain impulses.

Using a fan to reduce body temperature is an example of which mechanism of heat loss? a. Evaporation b. Radiation c. Convection d. Conduction

ANS: C Only convection causes the transfer of heat through currents of gases or liquids.

Open-angle glaucoma occurs because of: a. Decreased production of aqueous humor b. Increased production of vitreous humor c. Obstructed outflow of aqueous humor d. Excessive destruction of vitreous humor

ANS: C Open-angle glaucoma occurs because of an obstruction of the outflow of aqueous humor at trabecular meshwork or Schlemm canal. The remaining options fail to accurately describe the cause of open-angle glaucoma.

Which term is also used to refer to paradoxic sleep? a. Non-REM b. Light c. REM d. Delta wave

ANS: C REM sleep is also known as paradoxic sleep because the electroencephalographic (EEG) pattern is similar to the normal awake pattern. None of the other terms are used to identify paradoxic sleep.

Which neuropeptide promotes wakefulness? a. Prostaglandin D2 b. L-tryptophan c. Hypocretins d. Growth factors

ANS: C The hypothalamus, as a major sleep center, secretes hypocretins (orexins), which are neuropeptides that promote wakefulness and rapid eye movement (REM) sleep, as well as appetite, energy consumption, and pleasure or reward. The remaining options do not fulfill this objective.

Which medication is used to reverse the effects of malignant hyperthermia? a. Propranolol b. Diazepam c. Dantrolene sodium d. Sodium carbonate

ANS: C Treatment includes the withdrawal of the provoking agents and the administration of dantrolene sodium (a skeletal relaxant that inhibits calcium release during muscle contraction). The other options are not effective in the treatment of malignant hyperthermia.

The major sleep center is located in which section of the brain? a. Thalamus b. Brainstem c. Frontal lobe d. Hypothalamus

ANS: D A small group of hypothalamic nerve cells, the suprachiasmatic nucleus (SCN), controls the timing of the sleep-wake cycle and coordinates this cycle with circadian rhythms (24-hour rhythm cycles) in areas of the brain and other tissues. The remaining options do not fulfill this objective.

Pinkeye is characterized by inflammation of which structure? a. Eyelids b. Sebaceous glands c. Meibomian glands d. Conjunctiva

ANS: D Acute bacterial conjunctivitis (pinkeye) is an inflammation of the conjunctiva (mucous membrane covering the front part of the eyeball). The other structures are not affected by this inflammation.

When caring for a person who has experienced pain for 3 days, anxiety is likely to produce which physical signs that a nurse would expect to find? a. Fever and muscle weakness or reports of fatigue b. Irritability and depression or reports of constipation c. Decreased blood pressure or reports of fatigue d. Increased heart rate and respiratory rate with diaphoresis

ANS: D Anxiety is common in acute pain states and is usually apparent in the alterations of vital signs and can include elevation of blood sugar levels, decreases in gastric acid secretion and intestinal motility, and a general decrease in blood flow to the viscera and skin. Nausea occasionally occurs. The other symptoms are not generally associated with an anxiety response to acute pain.

Which cytokines are endogenous pyrogens?* a. IL-3, IL-10, and IL-18 b. IL-2, IL-8, and IFN-b c. IL-4, IL-12, colony-stimulating factor, and IFN-a d. IL-1, IL-6, TNF-a, and IFN-g

ANS: D Endogenous pyrogens include prostaglandin E2 (PGE2), interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-a), and interferon-gamma (IFN-g). The other options are not endogenous pyrogens.

Which spinal tract carries the most nociceptive information? a. Archeospinothalamic b. Paleospinothalamic c. Dorsal spinothalamic d. Lateral spinothalamic

ANS: D Most nociceptive information travels by means of ascending columns in the lateral spinothalamic tract (also called the anterolateral funiculus). The other tract options do not carry the most nociceptive information.