Alterations in thermoregulation

Question 1

Core body temperature (i.e., intracranial, intrathoracic, and intraabdominal) normally is maintained within a range of ______ to ______

Answer 1

36 C - 37.5 C

Question 2

the core body temperature is generally lowest between ___ and ___ and highest during the late afternoon, ____ to ____ PM.

Answer 2

lowest 3-6am

highest 3-6pm

Question 3

______ ______ _____________ is a reflection of the balance between heat gain and heat loss by the body. Metabolic processes produce heat, which must be dissipated.

Answer 3

core body temp

Question 4

The ___________ is the thermal control center for the body, receives information from peripheral and central thermoreceptors, and compares that information with its temperature set point.

Answer 4

hypothalamus

Question 5

A/an (decrease/increase) in core temperature is effected by vasoconstriction and shivering, a/an (decrease/increase) in temperature by vasodilation and sweating.

Answer 5

decrease, constriction and shivering

increase, vasodilation and sweating

Question 6

Most of the body’s heat is produced by the ________ ______ _________ which are insulated from the environment and protected against heat loss by an outer shell of subcutaneous tissues and skin

Answer 6

deeper core tissues (i.e., muscles and viscera)

Question 7

In general, the ________ temperature is used as a measure of core temperature and is considered the most accurate parameter.

Answer 7

rectal

Question 8

_______ _______ __________ is the preferred measurement when body temperatures are changing rapidly and need to be followed reliably on an acutely ill person in an intensive care setting.

Answer 8

pulmonary artery catheter

Question 9

Core body and skin temperatures are sensed and integrated by thermoregulatory regions in the __________ and other brain structures (i.e., thalamus and cerebral cortex).

Answer 9

hypothalamus (particularly, the preoptic–anterior hypothalamic area)

Question 10

Core temperatures above 41°C (105.8°F) or below 34°C (93.2°F) usually mean that the body’s ability to thermoregulate has been

Answer 10

impaired

Question 11

Spinal cord injuries that transect the cord at ___ or above can seriously impair temperature regulation because the thermoregulatory centers in the hypothalamus can no longer control skin blood flow and sweating.

Answer 11

T6

Question 12

___________ is the body’s main source of heat production or thermogenesis.

Answer 12

metabolism

Question 13

The sympathetic neurotransmitters, ________ and ______, which are released when an increase in body temperature is needed, act at the cellular level to shift body metabolism to heat production rather than energy generation. This may be one of the reasons fever tends to produce feelings of weakness and fatigue.

Answer 13

epi and NE

Question 14

_______ hormone increases cellular metabolism, but this response usually requires several weeks to reach maximal effectiveness.

Answer 14

thyroid

Question 15

__________ is initiated by impulses from the hypothalamus. Although it is an attempt to decrease the body temperature, it actually increases it and increases the use of oxygen by approximately 40%.7

Answer 15

shivering

Question 16

Most of the body’s heat losses occur at the ______ _____ as heat from the blood moves to the skin and from there into the surrounding environment.

Answer 16

skin surface

Question 17

There are numerous arteriovenous (AV) anastomoses under the skin surface that allow blood to move directly from the arterial to the venous system.3 These AV anastomoses are much like the radiators in a heating system. When the shunts are open, body heat is freely dissipated to the skin and surrounding environment; when the shunts are closed, heat is retained in the body. The blood flow in the AV anastomoses is controlled almost exclusively by the ________ in response to changes in core temperature and environmental temperature.

Answer 17

SNS

Question 18

Contraction of the pilomotor muscles of the skin, which raises skin hairs and produces goose bumps, also aids in heat conservation by

Answer 18

reducing the surface area available for heat loss.

Question 19

only heat losses that occur at the skin surface are directly under ___________ control.

Answer 19

hypothalamic

Question 20

__________ is the transfer of heat through air or a vacuum.

Answer 20

radiation

Question 21

Environmental temperature must be less than that of the body for heat loss to occur by way of __________

Answer 21

radiation

Question 22

______________ is the direct transfer of heat from one molecule to another.

Answer 22

conduction

Question 23

Blood carries heat from the inner core of the body to the skin surface by way of

Answer 23

conduction

Question 24

_______ has a specific heat several times greater than air, so it absorbs far greater amounts of heat than air does.

Answer 24

water

The loss of body heat can be excessive and life threatening in situations of cold water immersion or cold exposure in damp or wet clothing.

Question 25

The conduction of heat to the body’s surface is influenced by ______ ________

Answer 25

blood volume In hot weather, the body compensates by increasing blood volume as a means of dissipating heat. A mild swelling of the ankles during hot weather provides evidence of blood volume expansion. Exposure to cold produces a cold diuresis and a reduction in blood volume as a means of controlling the transfer of heat to the body’s surface.

Question 26

_________ refers to heat transfer through the circulation of air currents.

Answer 26

convection

Question 27

The wind-chill factor that often is included in the weather report combines the effect of ___________ due to wind with the still-air temperature.

Answer 27

convection

Question 28

___________ involves the use of body heat to convert water on the skin to water vapor.

Answer 28

evaporation

Question 29

Water that diffuses through the skin independent of sweating is called __________ ___________

Answer 29

insensible perspiration

Question 30

Sweating occurs through the sweat glands and is controlled by the ______

Answer 30

SNS

Question 31

Sweating is mediated by ____

Answer 31

ACH

Question 32

anticholinergic drugs, such as atropine, can interfere with heat loss by interrupting ________

Answer 32

sweating

Question 33

________ or _______ describes an elevation in body temperature that is caused by an upward displacement of the thermostatic set point of the hypothalamic thermoregulatory center.

Answer 33

fever or pyrexia

Question 34

___________ is one of the most frequent physiologic responses to be monitored during illness.

Answer 34

temp

Question 35

________ is a nonspecific response that is mediated by endogenous pyrogens released from host cells in response to infectious or noninfectious disorders.

Answer 35

fever

Question 36

_________ are exogenous or endogenous substances that produce fever.

Answer 36

pyrogens

Question 37

__________ ___________ are derived from outside the body and include such substances as bacterial products, bacterial toxins, or whole microorganisms.

Answer 37

exogenous pyrogens

Question 38

Exogenous pyrogens induce host cells to produce fever-producing mediators called ___________ ___________

Answer 38

endogenous pyrogens

Question 39

When bacteria or breakdown products of bacteria are present in blood or tissues, phagocytic cells of the immune system engulf them. These phagocytic cells digest the bacterial products and then release pyrogenic __________, principally interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), into the bloodstream for transport to the hypothalamus, where they exert their action.

Answer 39

cytokines

Question 40

Many noninfectious disorders, such as myocardial infarction, pulmonary emboli, and neoplasms, produce fever. In these conditions, the injured or abnormal cells incite the production of __________ _________

Answer 40

endogenous pyrogens

Question 41

trauma and surgery can be associated with up to ____ days of fever.

Answer 41

3

Question 42

A fever that has its origin in the central nervous system is sometimes referred to as a ____________ ______

Answer 42

neurogenic fever

Question 43

neurogenic fever is usually is caused by damage to the ____________ due to central nervous system trauma, intracerebral bleeding, or an increase in intracranial pressure.

Answer 43

hypothalamus

Question 44

__________ ___________ is characterized by a high temperature that is resistant to antipyretic therapy and is not associated with sweating.

Answer 44

neurogenic fever

Question 45

It has also been shown that small elevations in temperature such as those that occur with fever enhance immune function by ____ ___________ proliferation.

Answer 45

T lymphocyte

Question 46

Many of the microbial agents that cause infection grow best at normal body temperatures, and their growth is _________ by temperatures in the fever range.

Answer 46

inhibited

Question 47

fever is negative in many situations such as in older adults who have cardiac or pulmonary disease because it causes more of a demand for __________

Answer 47

oxygen

Question 48

Fever can also produce (3)

Answer 48

tachycardia confusion tachypnea

Question 49

Cell damage can occur when temperatures are elevated greater than _______ and this can ultimately cause life-threatening acidosis, hypoxia, and hyperkalemia.

Answer 49

42.2°C (108°F)

Question 50

_________ fever is one in which temperature returns to normal at least once every 24 hours.

Answer 50

intermittent

Question 51

in a __________ fever, the temperature does not return to normal and varies a few degrees in either direction.

Answer 51

remittent

Question 52

In a ________ or ________ fever, the temperature remains above normal with minimal variations (usually <0.55°C or 1°F).

Answer 52

sustained or continuous

Question 53

_________ or _________ fever is one in which there is one or more episodes of fever, each as long as several days, with one or more days of normal temperature between episodes.

Answer 53

recurrent or relapsing

Question 54

Critical to the analysis of a fever pattern is the relation of heart rate to the level of temperature elevation. Most people respond to an increase in temperature with an appropriate _________ in heart rate.

Answer 54

increase

Question 55

a heart rate that is slower than would be anticipated can occur with ________ disease and drug fever

Answer 55

legionnaire

Question 56

heart rate that is more rapid than anticipated can be symptomatic of what two patho processes?

Answer 56

hyperthyroidism and pulmonary embolism

Question 57

During the first or _______ period of fever there are nonspecific complaints such as mild headache and fatigue, general malaise, and fleeting aches and pains.

Answer 57

prodromal

Question 58

During the second stage or ______, there is the uncomfortable sensation of being chilled and the onset of generalized shaking (rigors), although the temperature is rising. Vasoconstriction and piloerection usually precede the onset of shivering. At this point, the skin is pale and covered with goose flesh. There is a feeling of being cold and an urge to put on more clothing or covering and to curl up in a position that conserves body heat.

Answer 58

chill

Question 59

When the shivering has caused the body temperature to reach the new set point of the temperature control center, the shivering ceases, and a sensation of warmth develops. At this point, the third stage or ______ begins, during which cutaneous vasodilation occurs and the skin becomes warm and flushed.

Answer 59

flush

Question 60

The fourth, or _______, stage of the febrile response is marked by the initiation of sweating.

Answer 60

defervescence

Question 61

true or false all people go through all four stages of fever

Answer 61

false Sweating may be absent, and fever may develop gradually with no indication of a chill or shivering.

Question 62

Common clinical manifestations of fever are (4)

Answer 62

anorexia, myalgia, arthralgia, and fatigue

Question 63

in fever, heart rate is _____ and resp rate ________

Answer 63

both are increased

Question 64

__________ is a concern with fever because of sweating and the increased vapor losses due to the rapid respiratory rate.

Answer 64

dehydration

Question 65

With prolonged fever, there is an increased breakdown of endogenous fat stores. If fat breakdown is rapid, _______ _______ may result.

Answer 65

metabolic acidosis

Question 66

_________ is a common accompaniment of fever and is thought to result from the vasodilation of cerebral vessels occurring with fever.

Answer 66

headache

Question 67

Herpetic lesions, or fever blisters, that develop in some people during fever are caused by a separate infection by ____ _______ that established latency in the regional ganglia and is reactivated by a rise in body temperature.

Answer 67

type 1 HSV

Question 68

Owing to increasingly poor oxygen uptake by the aging lung, pulmonary function may prove to be a limiting factor in the hypermetabolism that accompanies fever in what population

Answer 68

elderly

Question 69

Confusion, incoordination, and agitation commonly reflect _____ _______ in elderly people with fever

Answer 69

cerebral hypoxia

Question 70

_____ is defined as a temperature elevation of 38.3°C (101°F) or higher that is present for 3 weeks or longer and includes 1 week of comprehensive diagnostic testing that does not identify a diagnosis.

Answer 70

fever of unknown origin

Question 71

Malignancies, particularly __________ _______, are important causes of FUO in the elderly

Answer 71

non-hodgkin lymphoma

Question 72

causes of fever of unknown origin

Answer 72

``` lymphoma liver/CNS metastasis TB HIV abscessed infections drug fever cirrhosis ```

Question 73

Conditions in which recurrent fevers occur but do not follow a strictly periodic pattern include genetic disorders such as

Answer 73

familial mediterranean fever

Question 74

_____________ an autosomal recessive disease, is characterized by an early age of onset (<20 years) of acute episodic bouts of peritonitis and high fever with an average duration of less than 2 days. In some cases pleuritis, pericarditis, and arthritis are present. The primary chronic complication is the presence of serum antibodies that can result in kidney or heart failure.

Answer 74

familial mediterranean fever

Question 75

Other conditions that present with recurrent fevers occurring at irregular intervals include repeated viral or bacterial infections, parasitic and fungal infections, and some inflammatory conditions, such as ______ and ________

Answer 75

SLE and crohns

Question 76

Modification of the environment ensures that the environmental temperature facilitates heat transfer away from the body. how can we accomplish this?

Answer 76

sponge bath with cool water alcohol solution caution patient is not cooled too quickly

Question 77

More profound cooling can be accomplished through the use of forced air blankets or a cooling mattress, which facilitates the _________ of heat from the body into the coolant solution that circulates through the mattress. Care must be taken so that the cooling method does not produce vasoconstriction and shivering that decrease heat loss and increase heat production.

Answer 77

conduction

Question 78

_______ and _________ are needed to support the hypermetabolic state and prevent the tissue breakdown that is characteristic of fever.

Answer 78

fluids and simple carbs. Additional replacement fluids are needed for sweating and to balance the insensible water losses from the lungs that accompany an increase in respiratory rate. Fluids also are needed to maintain an adequate vascular volume for heat transport to the skin surface.

Question 79

It is thought that these drugs act by resetting the set point of the temperature-regulating center in the hypothalamus to a lower level, presumably by blocking the activity of cyclooxygenase, an enzyme that is required for the conversion of arachidonic acid to PGE2.

Answer 79

antipyretics ibuprofen aspirin tylenol

Question 80

evidence suggests that the routine administration of antipyretics (does/does not) decrease the duration of the fever or illness.

Answer 80

does not

Question 81

Because of the risk of _____ ________, the Centers for Disease Control and Prevention, U.S. Food and Drug Administration, and American Academy of Pediatrics Committee on Infectious Diseases advise against the use of aspirin and other salicylates in children with influenza or chickenpox.

Answer 81

reye syndrome

Question 82

infants and young children are more commonly infected with virulent organisms that cause fever because

Answer 82

decreased immune function and the mechanisms for controlling temperature are not as well developed in infants as they are in older children and adults

Question 83

In the elderly, even slight elevations in temperature may indicate serious infection or disease, most often caused by _______. This is because the elderly often have a lower baseline temperature, and although they increase their temperature during an infection, it may fail to reach a level that is equated with significant fever.

Answer 83

bacteria

Question 84

Signs of infection in older adults when fever is absent include

Answer 84

unexplained changes in functional capacity, worsening of mental status, weakness and fatigue, and weight loss.

Question 85

It has been suggested that ____ and ________ membrane methods are more effective in detecting fever in the elderly.

Answer 85

rectal and tympanic This is because conditions such as mouth breathing, tongue tremors, and agitation often make it difficult to obtain accurate oral temperatures in older adults.

Question 86

__________ describes an increase in body temperature that occurs without a change in the set point of the hypothalamic thermoregulatory center.

Answer 86

hyperthermia

Question 87

hyperthermia symptoms include (in order of increasing severity)

Answer 87

heat cramps heat exhaustion heat stroke

Question 88

If muscle exertion is continued for long periods in warm weather, as often happens with athletes, military recruits, and laborers, excessive heat loads are generated and may lead to

Answer 88

hyperthermia

Question 89

Because adequate circulatory function is essential for heat dissipation, elderly people and those with cardiovascular disease are at increased risk for _________

Answer 89

hyperthermia

Question 90

The best approach to heat-related disorders is

Answer 90

prevention primarily by avoiding activity in hot environments, increasing fluid intake, and wearing climate- and activity-appropriate clothing.

Question 91

__________ ___________ is an autosomal dominant disorder in which an abnormal release of intracellular stores of calcium causes uncontrolled skeletal muscle contractions, resulting in a rapid increase in core body temperature. This usually is in response to an anesthetic.

Answer 91

malignant hyperthermia

Question 92

_______ _______ are slow, painful, skeletal muscle cramps and spasms, usually occurring in the muscles that are most heavily used and lasting for 1 to 3 minutes.

Answer 92

heat cramps

Question 93

heat Cramping results from ________ depletion that occurs when fluid losses from heavy sweating are replaced by water alone.

Answer 93

salt

Question 94

______ __________ is related to a gradual loss of salt and water, usually after prolonged and heavy exertion in a hot environment. The symptoms include thirst, fatigue, nausea, oliguria, giddiness, GI/flu like sx and finally delirium.

Answer 94

heat exhaustion

Question 95

Hyperventilation in association with heat exhaustion may contribute to heat cramps and tetany by causing

Answer 95

resp alkalosis

Question 96

_________ is a severe, life-threatening failure of thermoregulatory mechanisms resulting in an excessive increase in body temperature—a core temperature greater than 40°C (104°F); a hot, dry skin; absence of sweating; and possible central nervous system abnormalities such as delirium, convulsions, and loss of consciousness

Answer 96

heatstroke

Question 97

The risk of developing heatstroke in response to heat stress is increased in conditions or drugs that impair vasodilation and sweat such as

Answer 97

alcoholism, obesity, diabetes mellitus, and chronic cardiac, renal, or mental disease alcohol, anticholinergics, beta blockers, or tricyclic antidepressants

Question 98

The pathophysiology of heatstroke is thought to result from the direct effect of heat on body cells and the release of ___________ from heat-stressed endothelial cells, leukocytes, and epithelial cells that protect against tissue injury.

Answer 98

cytokines (e.g., interleukins, TNF-α, and interferon)

Question 99

The net result of _________ is a combination of local and systemic inflammatory responses that may result in acute respiratory distress syndrome, acute renal failure, disseminated intravascular coagulation, and multiorgan disorders.

Answer 99

heatstroke

Question 100

The symptoms of heatstroke include

Answer 100

tachycardia, hyperventilation, dizziness, weakness, emotional lability, nausea and vomiting, confusion, delirium, blurred vision, convulsions, collapse, and coma.

Question 101

The most common cause of drug fever is

Answer 101

hypersensitivity reactions

Question 102

Hypersensitivity drug fevers develop after ______ ________ of exposure to the drug, cannot be explained in terms of the drug’s pharmacologic action, are not related to drug dose, disappear when the drug is stopped, and reappear when the drug is readministered.

Answer 102

several weeks

Question 103

Persons with drug fevers often experience other signs of hypersensitivity reactions, such as

Answer 103

``` arthralgias myalgias GI urticaria rash ```

Question 104

The absence of an appropriate increase in heart rate for the degree of temperature elevation is an important clue to the diagnosis of

Answer 104

drug fever

Question 105

The muscle contraction seen in malignant hyperthermia is caused by an abnormal release of intracellular ________ from the sarcoplasmic reticulum through calcium release channels.

Answer 105

calcium

Question 106

This condition is particularly dangerous in a young person who has a large muscle mass to generate heat.

Answer 106

malignant hyperthermia

Question 107

In addition to a steady rise in end-tidal carbon dioxide levels, an initial sign of the disorder, when the condition occurs during anesthesia, is

Answer 107

skeletal muscle rigidity

Question 108

______ ________ and a hypermetabolic state follow in rapid sequence unless the triggering event is immediately discontinued in the case of malignant hyperthermia

Answer 108

cardiac arrhythmias

Question 109

In addition to discontinuing the triggering agents, treatment of malignant hyperthermia includes measures to cool the body, cardiopulmonary support, and the administration of _____________, a muscle relaxant drug that acts by blocking the release of calcium from the sarcoplasmic reticulum.

Answer 109

dantrolene

Question 110

The neuroleptic malignant syndrome is associated with neuroleptic (psychotropic) medications and may occur in as many as 0.02% to 3.23% of people taking such drugs.2 Most of these drugs block _________ receptors in the basal ganglia and hypothalamus

Answer 110

dopamine

Question 111

The syndrome usually has an explosive onset and is characterized by hyperthermia, muscle rigidity, alterations in consciousness, and autonomic nervous system dysfunction. The hyperthermia is accompanied by tachycardia, cardiac dysrhythmias, labile blood pressure dyspnea, and tachypnea.

Answer 111

neuroleptic syndrome