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Flashcards in Thermoregulation Deck (102)
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1

Thermoneutral zone

The thermal zone which is suitable for the subjective demands of animals

2

Centre of thermoregulation

Hypothalamus

3

Animals can be divided into which groups of thermoregulation

  • Poikilothermic animals
  • Heterothermic animals
  • Homeothermic animals

4

Poikilothermic animals

Body temp. changes depending on environmental temp.

5

Heterothermic animals

  • Body temp. independent of environmental temp.
  • Some time behave as poikilothermic animals

6

Homeothermic animals

  • Body temp. independent of environmental temp.
  • Permanently

7

Domestic animals belong to which thermogenic group?

Homeothermic animals

8

Core temperature is affected by...

  • Time of day
  • Feed intake
  • Muscular activity
  • Sex
  • Age

9

Beginning of hibernation

  • Metabolic rate decrease
  • Body temperature decrease

10

Awakening

  • Body temperature increase
  • Metabolic rate increase

11

Hibernating animals becomes transiently...

Poikilothermic

12

During a 3-month hibernation period....

  • CNS is the only system that remains at the core temperature
  • Achieved by special heating elements surrounding the brain

13

Hibernation is interrupted by...

  • Awakening phase (for a few hours)
  • This happens every 2-3 weeks
  • BMR rises 120-140%
  • Rapid warming
  • Feeding, micturate, defecate

14

Micturation

Urination

15

Aestivation

  • 'Hibernation' in high environmental temperatures
  • In the middle of summer, inactive metabolic condition
  • Avoid dangers caused by dryness + heat

16

Torpor

  • Animal is in a still, rigid state
  • Observed in animals that cannot provide energy reserves at night
  • Decrease of metabolic speed
  • Body temp. = near environmental temp.
  • Heat of the sun + increased BMR activates the animal again

E.g Hummingbird

17

The temperature of body parts

  • Limbs are colder than the core
  • The ratio of unsaturated fatty acids in the limbs is higher in polar animals

18

Coolin of the limbs is inhibited by...

Efficient heat exchange systems

19

One-way heat exchanger

  • Low efficiency
  • Effluent temp. gives the average of incoming temps.

20

Looping heat-exchange

  • Most effective defence against heat loss
  • Between the body and the ground

21

Counter-current heat exchanger

  • More effective than unidirectional heat exchange
  • Heat flowing out can be almost fully transferred in
  • Temp of substance leaving warm branch = Temp of substance entering the cold branch
  • Observed in domestic animals - Deep blood vessel systems

22

Influence of age on body temperature

  • High temp in young animals - Higher BMR
  • Thermoneutral zone becomes narrower as age increases

23

Thermoneutral zone

Value where animals consume the least amount of oxygen

24

Heat balance

  • Occurs in normal conditions
  • Total body heat (Ht) divided into:
    • Produced heat
      • Hm (Metabolic)
      • Hs (Chemical)
    • Exchanged heat
      • Hc (Convection)
      • Hr (Radiation)
      • He (Evaporation)

25

Heat exchange occurs via...

  • Radiation
  • conduction
  • evaporation
  • Convection

from blood

 

26

Describe heat loss at the skin

  1. Air warmed by skin becomes lighter
  2. This air leaves the area of the skin
  3. Replaced by cold air

27

What is an important element of environmental temperature adaptation?

  • The thickness of adipose layer

Adipose/muscle are poor conductors

28

Calculate the rate of heat-loss by radiation/convection

A = surface area

t2-t1 = Thermal gradient

k = Constant (depends on the given material)

l = Distance the heat covers

29

Heat reception is accomplished by...

Central and peripheral cold and heat sensors

30

Simultaneous activity of heating and cooling areas adjusts...

  • Heat loss
  • Heat conservation
  • Heat production