Thermoregulation in endotherms

Question 1

How are temperature changes detects?

Answer 1

• peripheral temperature receptors are in the skin
  
  • detect changes in the surface temperature
• temperature receptors in the hypothalmus detect the temp of the blood deep in the body - less likely to be affected
• the combination of the two gives the body great sensitivity and allows it to respond to possible problems that might result

Question 2

How do endotherms warm up passively?

Answer 2

• behavioural adaptations same as ecotherms
• • some ani,als become dormant through the coldest weather (hibernation) or through the hottest weather (aestivation)

Question 3

What is aestivation

Answer 3

• period of prlonged sleep similar to hibernation but occurs in summer or during dry season to avoid heat stres rather than cold

Question 4

How do humans adapt to control body temp?

Answer 4

• wear clothes
• houses are built and heated up or coold down

Question 5

What is the heat loss centre?

Answer 5

• this is activated when the temp of the blood flowing through the hypothalmus increases
• it sends impulses through autonomic motor neurones to effects in the skin and muscles
• triggering responses that act to lower the core temp

Question 6

Why is it more difficult for a insect to maintain their body temperature compared to a mammal?

Answer 6

• insects have a smaller SA:V ration
  
  • greater rate of heat loss
• mammals have more insulation
  
  • thicker layer of fat surrounnding tissue
• mammals have better heat control systems
  
  • e.g. sweat

Question 7

Moths are insulated with scales and hair and are known as faculative endotherms.

Why are moths describred as endothermic

Answer 7

• scales and hair reduce heat loss
• generate heat from respiration internally