Deck 17: Energy Balance and Temperature Regulation

Question 1

The lowest metabolic rate occurs

A) during sleep
B) during a basal metabolic rate determination
C) during exercise
D) after a meal
E) in males compared to females

Answer 1

A

Question 2

Which of the following is not a requirement for measurement of the basal metabolic rate (BMR)?

A) The person must not have exercised for at least 30 minutes.
B) The person must not have eaten any food within 12 hours.
C) The person must have slept at least seven hours the previous night.
D) The person should be at mental rest during the measurement.
E) The measurement should take place at a comfortable room temperature.

Answer 2

C

Question 3

If more energy is contained in the food eaten than is expended

A) A positive energy balance will exist.
B) The excess energy will be stored in adipose.
C) All of the excess energy will be liberated.
D) A positive energy balance will exist and the excess energy will be stored in adipose.
E) A positive energy balance will exist and all of the excess energy will be liberated.

Answer 3

D

Question 4

The satiety center is located in the ____ of the brain.

A) cerebellum
B) cerebrum
C) hypothalamus
D) medulla
E) thalamus

Question 5

The factor that increases the metabolic rate to the greatest extent is increased

A) skeletal muscle activity
B) mental effort
C) dietary fiber intake
D) epinephrine secretion
E) brown fat deposition

Question 6

Internal work

A) includes all of the energy-expending activities that must go on all of the time to sustain life
B) refers to all energy expenditure by tissues other than skeletal muscles
C) includes the energy expenditure required to move external objects
D) includes all of the energy-expending activities that must go on all of the time to sustain life, and refers to all energy expenditure by tissues other than skeletal muscles
E) all of these

Question 7

Which statement is incorrect?

A) There are a pair of feeding centers and a pair of satiety centers in the hypothalamus that play a major role in controlling food intake.
B) Stimulation of the feeding centers drives the individual to eat.
C) Stimulation of the satiety centers brings about the feeling of having had enough to eat.
D) Distention of the digestive tract constitutes the major input for regulating food intake.
E) Destruction of the satiety center in lab animals leads to overeating and obesity.

Question 8

____ percent of the energy found in nutrient molecules is lost as heat.

A) 10
B) 25
C) 50
D) 75
E) 90

Question 9

5,300 calories is ____ kilocalories.

A) 00.53
B) 0.53
C) 5.3
D) 53
E) 5,300,000

Question 10

When a negative energy balance exists

A) The body must make use of stored energy reserves.
B) The caloric content of the food ingested is less than the energy output.
C) The caloric content of the food ingested exceeds the energy lost due to heat or work.
D) Energy has been destroyed by catabolic processes within the body.
E) The body must make use of stored energy reserves, and the caloric content of the food ingested is less than the energy output

Question 11

____ increases metabolic rate.

A) Exercise
B) Diet-induced thermogenesis
C) Epinephrine
D) Thyroid hormone
E) All of these

Question 12

About ____ kilocalories of energy is liberated by consumption of three liters of oxygen.

A) 4.8
B) 9.6
C) 14.4
D) 19.2
E) 24

Question 13

There are approximately ____ kilocalories of energy liberated per ____ of O₂ consumed.

A) 3.8; milliliter
B) 4.8; 10 liters
C) 4.8; liter
D) 4.0; 100 milliliters
E) both 3.8; milliliter and 4.8; liter

Question 14

Only about ____ percent of the energy found in nutrient molecules is transferred to ATP.

A) 10
B) 25
C) 50
D) 75
E) 90

Question 15

Select the hormone that is an important satiety signal.

A) ADH
B) Leptin
C) Glucagon
D) Glucose
E) TSH

Question 16

The energy equivalent of O₂ is

A) 4.8 kilocalories of energy liberated per liter of O₂ consumed
B) used to indirectly measure the metabolic rate
C) the energy required to raise 1 gm of H₂O 1 $\degree$ C
D) 4.8 kilocalories of energy liberated per liter of O₂ consumed and used to indirectly measure the metabolic rate
E) all of these

Question 17

Suppose a young woman consumes 1,200 ml of O₂ in a six-minute basal metabolic rate test period. What is her estimated basal metabolic rate?

A) 72 kcal/hour
B) 57.6 kcal/hour
C) 12 kcal/hour
D) 4 kcal/hour
E) none of these

Question 18

The energy equivalent of oxygen is the

A) number of calories contained in every liter of oxygen consumed
B) value that equates how much energy is liberated from food for every liter of oxygen consumed
C) oxygen consumption required for the processing and storage of ingested foodstuff
D) energy required to raise 1 g of H₂O 1 $\degree$ C
E) none of these

Question 19

Leptin

A) is secreted by adipocytes
B) leads to appetite suppression
C) targets the hypothalamus
D) is secreted by adipocytes and leads to appetite suppression
E) all of these

Question 20

Which of the following is not internal work?

A) energy required for active transport
B) energy required to pump blood
C) energy required to move the body in relation to the environment
D) energy used during synthetic reactions
E) energy used to maintain body posture

Question 21

The leading theory for maintenance of body weight as a result of long-term matching of food intake to energy expenditure relates to the

A) amount of fat stored in adipose tissue
B) extent of glucose utilization
C) magnitude of cellular ATP production
D) extent of gastrointestinal distention
E) extent of behavioral modification associated with eating habits

Question 22

Radiation and conduction are two types of heat exchange between the body and environment. The magnitude of heat loss via these two processes is determined by the

A) amount of sweating
B) temperature difference between body surface and its surroundings
C) absolute core temperature
D) extent of evaporation from the body surface
E) none of these

Question 23

____ has a positive effect on appetite.

A) CCK
B) PYY_3-36
C) Leptin
D) Insulin
E) Ghrelin

Question 24

Radiation

A) refers to heat emission from a warm object in the form of electromagnetic waves
B) is only a source of heat loss for the body (i.e., the body can lose but not gain heat by radiation)
C) refers to the transfer of heat by direct contact between a warmer and cooler object
D) involves the continued cycling of cool air over the body
E) refers to the transformation of water from a gaseous to a liquid state

Question 25

Which of the following is not a means of increasing or conserving heat production?

A) shivering
B) skin vasodilation
C) nonshivering thermogenesis
D) increased muscle tone
E) increased exercise

Question 26

Most people's core temperature varies by about ____ $\degree$ F.

A) 0.6
B) 1.8
C) 2.6
D) 4.0
E) 5.2

Question 27

"Normal" body temperature may vary slightly as a result of

A) exercise
B) the menstrual cycle
C) the time of day
D) exposure to extremes in environmental temperature
E) all of these

Question 28

On average, about half of the body heat that is lost is due to loss by

A) radiation
B) convection
C) conduction
D) evaporation
E) none of these

Question 29

The type of heat loss that occurs by sitting on a cold car seat is

A) radiation
B) convection
C) conduction
D) evaporation
E) none of these

Question 30

Heat can be lost directly to the external environment by the vasodilation of blood vessels in the ____.

A) hypothalamus
B) cerebellum
C) skin
D) cerebral cortex
E) medulla

Question 31

Sweating

A) causes vasodilation of the skin vessels
B) increases the insulative capacity of the skin so that less heat can be gained from the environment
C) is the only heat-loss mechanism available to the body when the environmental temperature is so high that a normal temperature gradient between the skin and the environment cannot be established
D) causes vasodilation of the skin vessels and is the only heat-loss mechanism available to the body when the environmental temperature is so high that a normal temperature gradient between the skin and the environment cannot be established.
E) all of these

Question 32

When the surrounding temperature is low, heat is lost from the body by means of

A) radiation
B) conduction/convection
C) nonshivering thermogenesis
D) radiation and conduction/convection
E) all of these

Question 33

Which does not act as a satiety signal?

A) cholecystokinin
B) increased glucose utilization
C) orexins
D) leptin
E) insulin

Question 34

The major means of increasing heat production in response to a cold environmental temperature is

A) skin vasoconstriction
B) wearing warm clothing
C) increased muscle activity, such as through shivering and increased voluntary exercise
D) formation of "goose bumps"
E) increased food intake

Question 35

Core temperature is

A) normally maintained relatively constant around 100 $\degree$ F
B) the temperature of the abdominal and thoracic organs, the central nervous system, and the skeletal muscles
C) the temperature of the skin and subcutaneous fat
D) the temperature of the abdominal and thoracic organs, the central nervous system, and the skeletal muscles; and is normally maintained relatively constant around 100 $\degree$ F
E) the temperature of the skin and subcutaneous fat, and normally maintained relatively constant around 100 $\degree$ F

Question 36

Sweating is

A) an active evaporative heat-loss process under sympathetic nervous control
B) the only means of losing heat when the environmental temperature is warmer than body temperature
C) the only means by which evaporative heat loss can take place in the body
D) an active evaporative heat-loss process under sympathetic nervous control and the only means of losing heat when the environmental temperature is warmer than body temperature
E) all of these

Question 37

Each of the following is a means of generating or holding heat in the body except

A) diminished sweating
B) exercising
C) shivering
D) vasodilation of blood vessels in the skin
E) behavioral adaptations

Question 38

A person can lose heat to an environment warmer than the body by means of

A) radiation
B) evaporation
C) conduction
D) radiation and conduction
E) evaporation and conduction

Question 39

Receptors that relay thermal information to the temperature control centers include

A) peripheral warm and cold thermoreceptors in the skin
B) central thermoreceptors in the hypothalamus
C) central thermoreceptors in internal organs
D) peripheral warm and cold thermoreceptors in the skin and central thermoreceptors in internal organs
E) all of these

Question 40

Most people suffer convulsions when internal body temperature reaches ____ $\degree$ F.

A) 96
B) 98
C) 100
D) 102
E) 106

Question 41

The development of fever

A) results from resetting of the medullary thermoregulatory center
B) may develop when mast cells release pyrogens
C) is mediated by prostaglandins
D) results from resetting of the medullary thermoregulatory center and may develop when mast cells release pyrogens
E) all of these

Question 42

When vasodilation of the blood vessels in the skin occurs:

A) The skin temperature becomes warmer than the core temperature.
B) The insulative capacity of the skin is increased.
C) Heat will be lost from the body if the air temperature is cooler than the skin temperature.
D) The insulative capacity of the skin is increased and heat will be lost from the body if the air temperature is cooler than the skin temperature.
E) All of these.

Question 43

Which of the following mechanisms help to maintain body temperature on hot days?

A) decreased muscle tone
B) skin vasodilation
C) sweating
D) only two of these
E) all of these

Question 44

Which of the following does not characterize heat exhaustion?

A) reduced plasma volume
B) extensive sweating
C) rapidly rising body temperature
D) fainting
E) reduced blood pressure

Question 45

Select the means of heat energy emission from the surface of a warm body.

A) radiation
B) conduction/convection
C) evaporation
D) radiation and evaporation
E) all of these

Question 46

Metabolic rate equals energy expenditure/unit of time.

Question 47

Energy cannot be created or destroyed, but it can be transformed from one form of energy into another.

Question 48

Internal work includes the expended energy when skeletal muscles are contracted to move external objects.

Question 49

There is an obligatory increase in metabolic rate resulting from food intake.

Question 50

The major means of decreasing heat loss in response to a cold environmental temperature is

A) skin vasoconstriction
B) skin vasodilation
C) increasing the temperature gradient between the skin and environment
D) formation of "goose bumps"
E) shivering

Question 51

Metabolic rate can be measured indirectly by measuring the rate of oxygen consumption.

Question 52

An endogenous pyrogen can be released by ____ in the body.

A) muscle cells
B) pathogens
C) platelets
D) erythrocytes
E) neutrophils

Question 53

The temperature control center within the anterior region of the hypothalamus is activated by ____ and initiates reflexes that mediate ____.

A) cold; heat production and heat conservation
B) cold; heat loss
C) warmth; heat loss
D) warmth; heat production and heat conservation
E) warmth; vasoconstriction

Question 54

The thermoneutral zone is

A) maintained by sweating and shivering mechanisms
B) the temperature within the body core that remains constant despite changes in environmental temperature
C) the environmental temperature range within which core temperature can be kept constant by skin vasomotor responses without calling supplementary heat-production or heat-loss mechanisms into play
D) the controlled environment within a building equipped with both heating and air-conditioning
E) the environmental temperature identical to core temperature so that body temperature is held constant without any physiological compensatory mechanisms being instituted

Question 55

Upon cold exposure all of the following occur except

A) skin vasoconstriction
B) decreased muscle tone
C) nonshivering thermogenesis
D) behavioral adaptations
E) stimulation of thermoreceptors

Question 56

Which statement is correct?

A) In a cold environment, the body will gain heat by conduction, convection, radiation, and evaporation.
B) In a hot environment when the temperature of the environment exceeds that of the skin surface, convection is the only means for the body to lose heat.
C) The temperature control centers in the hypothalamus receive afferent input from peripheral thermoreceptors in the skin and central thermoreceptors in the hypothalamus and internal organs.
D) All of these.
E) In a hot environment when the temperature of the environment exceeds that of the skin surface, convection is the only means for the body to lose heat; and the temperature control centers in the hypothalamus receive afferent input from peripheral thermoreceptors in the skin and central thermoreceptors in the hypothalamus and internal organs.

Question 57

Vasoconstriction of the blood vessels to the skin

A) is coordinated by the sympathetic nervous system
B) increases heat exchange with the environment
C) occurs when core body temperature is elevated
D) is coordinated by the sympathetic nervous system and increases heat exchange with the environment
E) increases heat exchange with the environment and occurs when core body temperature is elevated

Question 58

In fever production

A) Endogenous pyrogen released from neurons of the cerebral cortex in response to an infection elevates the hypothalamic "set point."
B) Eold response mechanisms are initiated by the hypothalamus to raise the body temperature to the new set point.
C) Heat loss mechanisms are triggered to eliminate the excess heat from the body.
D) Endogenous pyrogen released from neurons of the cerebral cortex in response to an infection elevates the hypothalamic "set point," and cold response mechanisms are initiated by the hypothalamus to raise the body temperature to the new set point.
E) Endogenous pyrogen released from neurons of the cerebral cortex in response to an infection elevates the hypothalamic "set point," and heat loss mechanisms are triggered to eliminate the excess heat from the body.

Question 59

Nonshivering thermogenesis

A) is stimulated by epinephrine and thyroid hormone
B) refers to the general increase in muscle tone in response to abrupt exposure to cold
C) enhances the insulative capacity of the skin by promoting increased deposition of brown fat under the skin
D) refers to the elevation of body temperature in response to pyrogen release
E) none of these

Question 60

Most of the energy contained within food will be lost as heat.

Question 61

The appetite centers stimulate feeding behavior, whereas the satiety centers inhibit feeding behavior.

Question 62

Overweight people tend to eat more on a daily basis than thinner people do.

Question 63

The inner core includes the abdominal and thoracic organs.

Question 64

An animal can be driven to overeat either by selective stimulation of the appetite centers or by destruction of the satiety centers.

Question 65

The most dominant factor influencing the BMR is the level of circulating, active thyroid hormone.

Question 66

The normal core temperature is 98.6 $\degree$ F (37 $\degree$ C).

Question 67

Leptin stimulates the release of melanocortins.

Question 68

Psychosocial influences can lead to obesity.

Question 69

The basal metabolic rate is the body's lowest metabolic rate.

Question 70

Weight loss occurs when the energy derived from the food consumed is less than the energy expended by the body.

Question 71

Leptin is a hormone released from adipose tissue.

Question 72

Rectal temperature is usually higher than core oral or axillary temperature.

Question 73

The core temperature is maintained at a near constant level, but skin temperature is quite variable.

Question 74

As the level of circulating, active thyroid hormone increases, the BMR increases correspondingly.

Question 75

Neuropeptide Y is a strong appetite inhibitor.

Question 76

The temperature control center in the posterior region of the hypothalamus is activated in response to cold exposure.

Question 77

A decrease of insulin in the blood may signal satiety.

Question 78

The skin thermoreceptors are capable of regulating core temperature in the absence of the hypothalamic temperature control centers.

Question 79

The feeding and satiety centers are located in the hypothalamus.

Question 80

Oral temperature is lower than the core temperature.