Midterm 4 Heat generation and energy balance Flashcards
(118 cards)
1
Q
What kind of process is catabolism?
an endogenic process while energy is released
a building process
proteins are formed from amino acids
polysaccharides are formed from fats
A
An endogenic process while energy is released
Burning fat or glucose as energy source
2
Q
What kind of process is anabolism?
an endogenic process while energy is released
a building process which needs energy for synthesis
a chemical reaction while compounds are transformed without energetic change
amino acids are formed from proteins
A
a building process which needs energy for synthesis
For example using proteins to build muscles or fat on the body
3
Q
Who introduced the law of conservation of energy?
H. A. Krebs
W. Harvey
A. L. Lavoisier and P. S. Laplace.
H. Starling
A
Lavoisier and Laplace
4
Q
Which hormone is important during long term adaptation to the changes in the environmental temperature?
noepinephrine
thyroid hormones
growth hormone
epinephrin
A
Thyroid hormones
5
Q
What is the most common reason for the increase of the metabolic rate?
milk production
nutrition of the fetus
increase of muscle work
sympathetic tone
A
Increase of muscle work
6
Q
Which growing animal has the best feed utilization?
lactating cow
pig
beef cattle
laying hen
A
Laying hen
7
Q
What is true for vital protein digestion?
the undigested defecated protein is subtracted from the fodder’s protein content
the undigested defecated protein and the endogenous nitrogen in the faeces are subtracted from the fodder’s protein content
it is independent of the quantity of endogenous nitrogen
it is the exact measurent of protein digestibility
A
The undigested defecated protein and the endogenous nitrogen in the faeces are subtracted from the fodder’s protein content
8
Q
How can the net protein utilization be measured?
during its measurement it is unnecessary to starve the animal
the endogenous nitrogen content of the faeces is subtracted from the virtual protein digestion
the urine nitrogen is subtracted from the ingested protein
the undigested defecated protein is subtracted from the fodder’s protein content
A
The urine nitrogen is subtracted from the ingested protein
9
Q
What information does the biological utilization give?
it states the reason of improper protein utilization
it gives information on how much is the real protein digestion
it gives information on how much of the given fodder is absorbed in the gut
it gives information on how much of the degraded and absorbed protein can take part the synthesis of the organism’s new proteins
A
it gives information on how much of the degraded and absorbed protein can take part the synthesis of the organism’s new proteins
10
Q
How can energy, which is released during metabolism, be calculated?
Energy released = stored energy - heat - work
Energy released = work + stored energy - heat
Energy released = (internal work - external work) + stored energy + heat
Energy released = stored energy + heat + work
A
Energy released = stored energy + heat + work
11
Q
What is the definition of one calorie?
1 calorie is defined as the amount of energy required to raise the temperature of one gram of water from 14.5 °C to 15.5 °C
1 calorie is defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius
1 calorie is defined as the amount of energy released by combustion of 1 g of foodstuff
Calorie is a general unit of measurement for heat, work, and energy
A
1 calorie is defined as the amount of energy required to raise the temperature of one gram of water from 14.5 °C to 15.5 °C
12
Q
Which of the measuring units below is associated the quantity of heat?
Calorie
Joule
Kcal
°C
A
Joule
13
Q
What is the combustion heat for nutrients?
the amount of heat produced by burning of 1 g protein
the amount of heat produced by burning of 1 g foodstuff
the amount of heat produced by burning of 1 g particular nutrient
the difference between the energy released in the bomb calorimeter and the in the body
A
The amount of heat produced by burning of 1g particular nutrient
14
Q
How can you determine the total heat energy in the foodstuff?
By direct calorimetry
By indirect calorimetry
By calculation
By bomb calorimeter
A
By bomb calorimeter
15
Q
What is the “Hess law”?
The amount of energy released by oxidation is independent of the intermediate steps
Oxidation of proteins releases the same amount energy in the body and in the bomb calorimeter
The oxidation has the same intermediate steps in the body and in the bomb calorimeter
The combustion heat of different nutrients depends on the intermediate steps
A
The combustion heat of different nutrients depends on the intermediate steps
16
Q
What is gross energy (GE)?
The difference of metabolizable energy and heat produced in the body
The energy content of the foodstuff measure in bomb calorimeter
GE = combustion heat - energy in faeces
GE = combustion heat - energy in faeces - energy in urine
A
The energy content of the foodstuff measure in the bomb calorimeter
17
Q
What is the real protein digestion?
the undigested defecated protein is subtracted from the protein content of the feed
the endogenous nitrogen content in the faeces is subtracted from the virtual protein digestion
during its determination it is unnecessary to starve the animal
the endogenous nitrogen content of the faeces and the urine nitrogen content are subtracted from the virtual protein digestion
A
the endogenous nitrogen content in the faeces is subtracted from the virtual protein digestion
18
Q
What is the digestible energy (DE)?
The energy content of the foodstuff measured in bomb calorimeter
DE = combustion heat - energy in faeces - energy in urine
DE = combustion heat - energy in faeces
The difference of metabolizable energy and heat produced in the body
A
DE = combustion heat - energy in faeces
19
Q
What is the metabolizable energy (ME)?
ME = net energy - energy in urine
The energy content of the foodstuff measure in bomb calorimeter
ME = combustion heat - energy in faeces
ME = DE - energy in urine - fermentation energy
A
ME = DE - energy in urine - fermentation energy
20
Q
What is net energy (NE)?
NE = metabolizable energy - heat loss - specific dynamic action
NE = DE - energy in urine - fermentation energy
The energy content of the foodstuff measure in bomb calorimeter
NE = combustion heat - energy in faeces - energy in urine
A
NE = metabolizable energy - heat loss - specific dynamic action
21
Q
In which species can the metabolizable energy be determined directly?
Ruminants
birds
carnivores
none of the above
A
Birds (they defecate and urinate at the same time through the cloaca)
22
Q
Which forms of energy can cover the needs of vital processes or can be utilized for production?
Metabolizable energy
Digestible energy
Net energy
Gross energy
A
Net energy
23
Q
What portion of the gross energy is lost with the urine?
20 %
10-60%
5-12%
3-5%
A
3-5%
24
Q
How much energy is lost with 1 mol of uric acid?
1925 kJ
634 kJ
1254 kJ
135 kJ
A
1925 kJ
25
What portion of the metabolizable energy is converted into net energy during pregnancy?
70 %
20 %
30-40%
90 %
20%
26
What portion of the metabolizable energy can be used for vital processes?
30-40%
90 %
70 %
20 %
70%
27
What is the basal metabolic rate?
The energy which is used to maintain constant body temperature
The energy which is used for vital processes
The energy production measured in standstill stage
The energy production measured in resting stage
The energy production measured in resting stage
28
What criteria determine the basal metabolic rate?
Complete resting, lying posture, absence of any psychic excitement, and neutral environmental temperature
natural environmental temperature, lying posture or having a rest, before morning feeding
standing posture, absence of any psychic excitement, and neutral environmental
temperature
Complete rest, standing posture, fasting
Complete resting, lying posture, absence of any psychic excitement, and neutral environmental temperature
Very hard to measure on animals
29
What criteria determine the resting metabolic rate?
Complete rest, lying posture, fasting, neutral environmental temperature
lying posture or having a rest, before morning feeding
can be measure only in humans, before food uptake, in absence of any psychic excitement
the specific dynamic action and the production energy have to be subtracted from the basal metabolic rate
Lying posture or having a rest, before morning feeding
30
What is the metabolic spectrum?
The energy turnover that is independent of the activity and production
Metabolic rate above the resting metabolic rate, which can be determined by measuring the oxygen consumption
Energy turnover above the basal metabolic rate (or resting metabolic rate)
Energy turnover which can be up to 100 folds of basal metabolic rate
Energy turnover above the basal metabolic rate (or resting metabolic rate)
31
Which statement is true for the Lavoisier's calorimetry?
The advantage is that it can be used on physically active animals
The water evaporated is absorbed by either H2SO4 or NaCO3
Water of known temperature is circulated in a copper tube in the heat isolated chamber; water is warmed up by the animal
The chamber, containing the animal, was surrounded by ice; the amounts of melted ice and the water being produced, were used for the estimation of heat generation
The chamber, containing the animal, was surrounded by ice; the amounts of melted ice and the water being produced, were used for the estimation of heat generation
32
How much energy is needed to melt 1 g of ice?
0. 334 kJ
0. 334 kcal
0. 585 kcal
0. 585 kJ
0.334 kJ
33
Which statement is true for the complex direct calorimetry?
The disadvantage is that it cannot be used on physically active animals
Water of known temperature is circulated in a copper tube in the heat- isolated chamber; water is warmed up by the animal
The chamber, containing the animal, was surrounded by ice; the amounts of melted ice and the water being produced, were used for the estimation of heat generation
Produced heat can be calculated by the energy which is needed to melt the ice
Water of known temperature is circulated in a copper tube in the heat-isolated chamber; water is warmed up by the animal
34
Which statement is true for the compensation calorimetry?
Water of known temperature is circulated in a copper tube in the heat- isolated chamber; water is warmed up by the animal
A double-walled chamber, the inner wall of which is a good conductor of heat, and the outer wall of which is kept under constant temperature.
The amount of heat dissipated through the wall of the chamber is measured in a way that the heat-difference
There are two chambers with identical thermal capacity, connected together and placed in a space with constant temperature; one of them contains the animal, the other a lamp
Measures the heat which is lost by radiation, conduction, and convection
There are two chambers with identical thermal capacity, connected together and placed in a space with constant temperature; one of them contains the animal, the other a lamp
35
Which statement is true for the gradient calorimetry?
Its disadvantage that it is complicated and not accurate
Measures only the heat which is lost by conduction
There are two chambers with identical thermal capacity, connected together and placed in a space with constant temperature; one of them contains the animal, the other a lamp
A double-walled chamber, the inner wall of which is a good conductor of heat, and the outer wall of which is kept under constant temperature. The amount of heat dissipated through the wall of the chamber is measured in a way that the heat- difference
4?
36
Why is the indirect calorimetry applied to monitor the energy balance?
More than 95% of energy utilized by the body is originated from the chemical reaction between oxygen and foodstuffs therefore the O2 is a reliable marker for energy turnover
Oxygen consumption gives information about the quality of food
The O2 is a reliable marker for energy turnover even during heavy physical activity
During combustion of 1 litre of oxygen, 20.18 J (4.825 cal) of energy is released
More than 95% of energy utilized by the body is originated from the chemical reaction between oxygen and foodstuffs therefore the O2 is a reliable marker for energy turnover
37
What is oxygen equivalency?
During combustion of 1 mol of oxygen, 1 mol of CO2 is released
During combustion of 1 litre of oxygen, 20.18 kJ (4.825 kcal) of energy is released
Combustion of 1 g fat requires the same amount of oxygen as 1 g carbohydrate
During combustion of 1 litre of oxygen, 20.18 J (4.825 cal) of energy is released
During combustion of 1 litre of oxygen, 20.18 kJ (4.825 kcal) of energy is released
38
What is the advantage of indirect calorimetry?
The O2 is a reliable marker for energy turnover even during heavy physical activity
Oxygen consumption gives information about the quality of the food
the animal can stay in its natural environment, it can move freely
there are no separate open and closed systems
the animal can stay in its natural environment, it can move freely
39
What is the disadvantage of indirect calorimetry?
During combustion of 1 litre of oxygen releases different amount of energy depending on the food quality
It is difficult to apply, the method is slow
The animal has to stay inside the laboratory
The method measures only O2- dependent energy production
The method measures only O2- dependent energy production
40
Which is the normal setup for open- system indirect calorimetry?
The amount and composition in the expired air is measured
The amount and CO2 content in the inspired air is measured
The amount and CO2 content in the expired air is measured
The amount and composition in the inspired air is measured
The amount and composition in the expired air is measured
41
What instrument is an open-system indirect calorimeter?
Krogh's device
Douglas bag
Knipping device
Haldane calorimeter
Douglas bag
42
Which is the normal setup for closed- system indirect calorimetry?
The amount and CO2 content of the expired air is measured and the oxygen consumption is deduced
The animal inspires from a closed bag and expires to the outside air
The animal is completely isolated from the outside air
The animal inspires from the outside air and expires into a closed bag
The animal is completely isolated from the outside air
43
What is the setup of the Krogh's device?
Expired CO2 can be measured by absorbing it with KOH
The oxygen used up is replenished and the volume measured
The device gives the possibility to measure both the oxygen consumption and the CO2 production
Oxygen is added previously to the system, then the amount of consumed oxygen is measured
Oxygen is added previously to the system, then the amount of consumed oxygen is measured
44
What is the respiratory quotient?
the volume of carbon dioxide produced divided by the volume oxygen consumed during the same time period
the volume of carbon dioxide produced minus the volume oxygen consumed during the same time period
the volume of carbon dioxide expired divided by the volume oxygen inspired during the same time period
gives information about the amount of fat, protein, and carbohydrate utilized
the volume of carbon dioxide produced divided by the volume oxygen consumed during the same time period
45
Combustion of which nutrient gives the most energy while using up 1 liter of oxygen?
Protein
Carbohydrate
Fat
the energy released is the same for all three nutrients above
Carbohydrates
46
What is the normal range of RQ?
0-1
0-10
0.7-1.0
0.5-0.7
0.7-1.0
47
What is RQ?
The respiratory quotient (or RQ or respiratory coefficient), is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body
48
When can the RQ go above 1?
During fasting
After heavy physical work
During conversion of amino acids to carbohydrates
During conversion of carbohydrates to fat
During conversion of carbohydrates to fat
49
When can the RQ go below 0.7?
During conversion of amino acids to carbohydrates
During conversion of carbohydrates to fat
During hyperventilation
During metabolic acidosis
During conversion of amino acids to carbohydrates
50
What is the normal setup for Atwater- Rosa type calorimetry?
The animal is placed into a chamber which is surrounded with ice - heat production is calculated by the amount ice melted
In the closed system the animal inspires a known amount of oxygen, the measurement of CO2 can be omitted
It is a combination of direct and indirect calorimetry
It works like an open-system indirect calorimetry, furthermore the heat production of the animal can be measured directly
It is a combination of direct and indirect calorimetry
51
What does the Kleiber's equation describe?
Basal metabolic rate shows a linear correlation with the body mass
The relative metabolic rate is higher in a large animals than in small ones
The metabolic rate as a logarithmic function of the body mass appears as a line with a slope of 0.5
metabolic rate is a function of the 0.75th power of body weight
metabolic rate is a function of the 0.75th power of body weight
52
What is the correlation between the metabolism and the body surface?
logarithmic
linear
exponential
no correlation
Logarithmic
53
Which of the below hormones has no effect on the metabolic rate?
Thyroid hormones
Calcitonin
Male sexual steroids
Growth hormone
Calcitonin
54
When does the metabolic rate decrease?
During increased production of thyroid hormones
During sympathetic activation
During sleeping
During growth hormone production
During sleeping
55
What is the specific dynamic action?
The proportion of energy which can be converted to metabolic energy
The proportion of energy which can be stored in the body
The energy released during the oxidation of foodstuff
The energy required for assimilation of foodstuff.
The energy required for assimilation of foodstuff.
56
Which of the below nutrients has the highest specific dynamic action?
Protein
fat
carbohydrates
volatile fatty acids
Protein
57
Which is the most important component of the specific dynamic action?
Energy used for digestion
Energy used for deamination in the liver
Energy used for absorption
Energy used for storing processes
Energy used for deamination in the liver
58
How will the metabolic rate change after food intake?
Decreases for 1-2 hours
Increases after an hour and remains high for 2-3 more hours
Increases after an hour then decreases
Does not change
Increases after an hour and remains high for 2-3 more hours
59
How does the body temperature alter the metabolic rate?
It does not change the metabolic rate
Decreasing body temperature increases metabolic rate
Increasing body temperature decreases metabolic rate
Increasing body temperature increases metabolic rate
Increasing body temperature increases metabolic rate
60
How does the environmental temperature alter the metabolic rate?
Metabolic rate is increased both below lower and above upper critical temperatures
Metabolic rate is decreased below the lower critical temperature and increases above the upper critical temperature
Metabolic rate is increased below the lower critical temperature and decreases above the upper critical temperature
The environmental temperature does not alter the metabolic rate significantly
Metabolic rate is increased both below lower and above upper critical temperatures
61
What is true for the body temperature of poikilothermic mammals?
the surface temperature of the body may change as a function of the environmental temperature
the core temperature of the animal changes according to the change in the surface temperature
the body temperature is constant all through the animal's life
in some periods of the day, the fodder ingestion and muscle activity have an effect on the body temperature
the surface temperature of the body may change as a function of the environmental temperature
(bat, hummingbird)
62
What is true for the body temperature of heterothermic animals?
the body temperature changes as a function of environmental temperature
the core temperature is independent of the environmental temperature but in certain physiological periods it may change
the body temperature is unrelated to environmental temperature
in some periods of the day, the fodder ingestion and muscle activity have an effect on the body temperature
The core temperature is independent of the environmental temperature but in certain physiological periods it may change
63
What is true for the body temperature of homeothermic animals?
the body temperature changes as a function of environmental temperature
the body temperature is unrelated to environmental temperature, in certain physiological periods the animal's temperature depends on the environmental temperature
the body temperature is unrelated to environmental temperature throughout the animal's life
the fodder ingestion and muscle activity have an effect on the core temperature
the body temperature is unrelated to environmental temperature throughout the animal's life
64
What has no effect on the core temperature?
muscle activity
feed ingestion
age
environmental temperature
Environmental temperature
65
What is true for the peripheral temperature of animals?
the temperature of the tissues which are in direct contact with the environment changes
the peripheral temperature and the core temperature change parallelly
the temperature of the tissues which are in direct contact with the environment is constant
the peripheral temperature is changed only by an extremely large change in the environmental temperature
the temperature of the tissues which are in direct contact with the environment changes
66
Which statement is correct for the core temperature of hibernating animals?
the core temperature is the same as the environmental temperature
the animals wake up regularly when their core temperature rises
the temperature in the intestine does not cool down in these animals
during the hibernation the core temperature is a little bit lower than the environmental temperature
The animals wake up regularly when their core temperature rises
67
What is aestivation?
a special form of hibernation in cold
the accumulation of fat for hibernation
it is a dormant state in summer
during a very cold night the animal becomes active
It is a dormant state in summer
68
What is the torpor?
it is the inactive state of the metabolism when the weather is hot and dry
the animals temperature increases continuously
it is active muscle work occurring to survive the cold period
during the cold night the animal becomes numb and its body temperature approaches the environmental temperature
during the cold night the animal becomes numb and its body temperature approaches the environmental temperatur
69
Which factor influences the normal core temperature the most?
Time of day
Age
Fodder ingestion
Sex
Age
70
How does the thermoneutral zone change with age?
the older the animal is, the narrower is the thermoneutral zone
the thermoneutral zone is not present in young animals
the younger the animal is, the narrower is the thermoneutral zone
age is unrelated to the neutral zone
the younger the animal is, the narrower is the thermoneutral zone
?
71
Why do the young animals have higher body temperatures?
the body surface is relatively small
they have worse adaptability to the environmental temperature than the older ones
they have a better adaptability to the environmental temperature than the older ones
they have a larger metabolic rate than the older ones
they have a larger metabolic rate than the older ones
72
Which factor does not belong to the exchangeable quantity of heat?
metabolic heat
conductive heat
radiation heat
evaporative heat
Metabolic heat
73
What best describes the radiation heat loss?
it is mediated by air
it is linearly related to the body surface area
it is exponentially related to body surface area
it is linearly related to the distance between the animal and the surrounding objects
it is exponentially related to body surface area
74
Which substance is the best heat conductor?
Epidermis
Hair
Muscle
Air
Muscle
75
Which process generates heat?
Radiation
Conduction
Piloerection
Shivering
Shivering
76
Which process results in no heat loss?
Piloerection
Evaporation
Conduction
Radiation
Piloerection
77
What is true for the thermoneutral zone?
This zone is constant in all species
In this zone the metabolic rate does not change
The body temperature is the lowest in this zone.
It is a part of the optimal zone
In this zone the metabolic rate does not change
78
What is characteristic of the optimum zone?
It is lower point is the Lower Critical Temperature
there is no metabolism in this phase
it is within the thermoneutral zone, the animal prefers this temperature
its upper point is the Upper Critical Temperature
it is within the thermoneutral zone, the animal prefers this temperature
79
What can changes below the Lower Critical Temperature be observed?
When energy production decreases but the body temperature does not change
when energy production and body temperature both decrease
when energy production increases and body temperature gradually decreases
energy production increases but the body temperature basically does not change
energy production increases but the body temperature basically does not change
80
What can changes above the Upper Critical Temperature be observed?
When energy production increases, first the temperature does not change but then increases
When energy production increases and the body temperature decreases or does not change
When energy production decreases and body temperature increases
When energy production decreases but body temperature does not change
When energy production increases, first the temperature does not change but then increases
81
What changes can be observed in hypothermia?
energy production increases and body temperature decreases
both energy production and body temperature decrease
energy production increases but body temperature does not change
energy production decreases but body temperature does not change
both energy production and body temperature decrease
82
What changes can be observed in hyperthermia?
energy production decreases but body temperature does not change
energy production does not change but body temperature increases
energy production decreases and body temperature increases
neither energy production nor body temperature changes
energy production decreases and body temperature increases
83
Which temperature interval listed below is the widest?
the one between the lower and the upper critical temperature
the optimum zone
the thermoneutral zone
the interval that can still be regulated
the interval that can still be regulated
84
Which are the physical elements of protection against the cold?
cuddling, shivering, chemical thermogenesis
perspiratio sensibilis and insensibilis
radiation, convection, conduction
spontaneous, synchronized contractions of the muscles, increase of metabolism
cuddling, shivering, chemical thermogenesis
85
What is the shivering thermogenesis?
defence mechanism - behavioral changes
thermogenic mechanism - the increase of muscular activity
heat produced during the enzymatic break- down and oxidation of body fat
utilization of thermal energy obtained from the outsid
thermogenic mechanism - the increase of muscular activity
86
What is conductive heat loss?
heat loss through water or air coming into contact with the body
heat loss in the form of electromagnetic waves
heat loss by coming in direct contact with a cold object
heat loss through water vaporization
heat loss by coming in direct contact with a cold object
87
What is convective heat loss?
heat loss by coming into direct contact with a cold object
heat loss in the form of electromagnetic waves
heat loss through liquid evaporized from the body surface
heat loss through water or air coming into direct contact with the body
heat loss through water or air coming into direct contact with the body
88
What is characteristic of radiation heat loss?
heat loss in the form of electromagnetic waves
heat loss by coming into direct contact with a cold object
heat loss through water or air coming into direct contact with the body
heat loss through water evaporation
heat loss in the form of electromagnetic waves
89
Which one is a "wet" form of heat loss?
conduction
evaporation
convection
radiation
Evaporation
90
Behavioral response is a part of which protective mechanism?
protection from cold
protection from heat
part of protection from both cold and heat
not part of the protection either from heat nor from cold
part of protection from both cold and heat
91
What are the advantages of panting?
during panting protection from heat needs no work investment
water loss is prevented by panting
all animal species are capable of heat loss through panting
the animal can regulate the extent of the heat loss through panting
the animal can regulate the extent of the heat loss through panting
92
To which heat loss mechanism does panting belong to?
perspiratio insensibilis
perspiratio sensibilis
conduction
radiation
perspiratio insensibilis
93
How much heat is needed to vaporize of 1 g of water?
2. 4 kcal
0. 58 kcal
0. 58 kJ
5. 8 kJ
0.58 kcal
94
Which animals contain sweat glands on their skin?
guinea-pig
rabbit
cattle
birds
Cattle
Horse?
95
Which animal does not have sweat glands?
rat
dog
cattle
rabbit
Rabbit
96
Sweating belongs to what heat loss mechanism?
perspiratio sensibilis
perspiratio insensibilis
conduction
convection
perspiratio sensibilis
97
What changes in the blood circulation can be observed in a hot environment?
the arteriovenosus anastomoses open up, the precapillary sphincters in the skin are closed, blood is led through the deep veins
the arteriovenosus anastomoses open and allow intensive perfusion in the surface regions
the precapillary sphincters are closed, venous blood is conducted through the surface veins
the precapillary sphincters are open, venous blood is conducted through the deep veins
the arteriovenosus anastomoses open and allow intensive perfusion in the surface regions
98
What characteristics of the blood circulation can be observed in cold environment?
the precapillary sphincters are closed, venous blood is conducted through the surface veins
the arteriovenosus anastomoses close and the precapillary sphincters close too so that blood is directed back to deep veins
the arteriovenous anastomoses are closed and the blood is led into capillaries of the skin, then it is conducted though the surface veins
the precapillary sphincters are open and venous blood is conducted through the deep veins
the arteriovenosus anastomoses close and the precapillary sphincters close too so that blood is directed back to deep veins
99
Which special structure ensures the protection of the testes in heat?
the looping exchanger system
rete mirabile
carotis rete
plexus pampiniformis
plexus pampiniformis
100
Which special structure ensures the protection of the feet of wading birds in the cold?
rete mirable
carotis rete
plexus pampiniformis
looping heat exchanger
Rete mirable
101
Which anatomical structure is protected from heat by the carotis rete?
the mucous membrane of the nose
brain and central nervous system
heart
sense organs
brain and central nervous system
102
What constitutes the afferentation of thermoregulation?
the set-point of the thermostate
stimulus starting from a receptor-site in the spinal cord
stimulus starting from the peripheral and central thermoreceptors informing the thermostate of the hypothalamus
stimulus originating from the peripheral cold receptors
stimulus starting from the peripheral and central thermoreceptors informing the thermostate of the hypothalamus
103
Where is the temperature control center?
in the pons
in the medulla oblongata
in the thalamus
in the hypothalamus
in the hypothalamus
104
What determines the value of the intrinsic core temperature?
the "set point" of temperature center of the hypothalamus
the "current" value of peripherial receptor system
the "must" value of the hypothalamic receptors
the "current" value of temperature center of the hypothalamus
the "set point" of temperature center of the hypothalamus
105
What are the practical occurrences of hypothermia?
fresh sheared sheep in rainy weather
in old, weaker animals in prolonged cold
heat loss in new born animals
in young animals in rainy, cold weather
heat loss in new born animals
106
What is true for hyperthermia?
the animals endure hyperthermia easier, than hypothermia
hypercapnia, paralysis of muscle
metabolism increases important, increasing of heart frequency cause the collapse of circulation
it results in insufficient function of temperature regulation
it results in insufficient function of temperature regulation
107
What kind of animal is the most sensitive to hypothermia?
piglets
horses
calves
chickens
Piglets
108
What is true for fever?
it affects adversely the organism
regulated hyperthermia which is caused by inflammation, destruction of tissue or any other disease
it is a special form of hyperthermia when temperature control falls out
it is caused by peripheral heat sensors
Regulated hyperthermia which is caused by inflammation, destruction of tissue or any other disease
109
What is an exogenous pyrogenic substance?
I1-and IL-6compounds which are produced during activation of macrophage
prostaglandin
endotoxin of Gram negative bacteria
it is a special protein which is produced in heat center of hypothalamus
endotoxin of Gram negative bacteria
110
Pyrogenic
Fever inducing
111
What happens at the beginning of a fever?
above all the organism increases the body temperature by heat conservation
the heat pass courses are activated
the "current" value is larger than the "must" value
the fever causes the increase of the "must" set point in the hypothalamus
the fever causes the increase of the "must" set point in the hypothalamus
112
What occurs at the end of a fever?
the "must" value returns back to the normal level and cooling mechanisms start
the "must" value of hypothalamus increases
heating mechanisms are activated
shivering is experienced
the "must" value returns back to the normal level and cooling mechanisms start
113
What kind of morpho-functional changes occur during cold acclimation?
secretion of glucocorticoids
the fur/feathers become stronger, the heat insulation thickens
vasodilatator mechanism activates
brown adipose tissue atrophies
the fur/feathers become stronger, the heat insulation thickens
114
Which is not true for heat acclimation?
thickness of the heat insulators decrease
vasodilator mechanism activates
function of breathing muscles decreases
sweat gland activates
function of breathing muscles decreases
115
Which substance ensures uncoupling during cellular thermogenesis?
special 23000kDa mass glucoproteid
cAMP
FFA
thermogenin
thermogenin (UCP 1)
116
Which hormones influence uncoupling?
thyroxine, epinephrine
glucocorticoid, epinephrine
norepinephrine, STH
FSH, STH
thyroxine, epinephrine
117
What is the function of thermogenin during the uncoupling mechanism?
it increases the catabolism of FFA
it allows protons to flow through the mitochondrial membranes without producing ATP
it inhibits the catabolism of ATP
it directly increases glucose uptake by the cells
it allows protons to flow through the mitochondrial membranes without producing ATP
118
In which tissue does uncoupling occur in?
white adipose tissue
liver
brown adipose tissue
muscle
Brown adipose tissue
