Thermoregulation pt. 2

Question 1

How and why do large flying insects warm up before flight?

Answer 1

Insect muscles are not able to function well at low temperatures. Warm up flight muscles by pre flight shivering to 35oC when the air temp is at 10oC

Question 2

How is heat retained in winter moths during flight ?

Answer 2

They retain heat using a heat exchanger, using counter current exchange. Heat produced by thoracic flight muscle hats up the rest of the thorax.

Question 3

How are honey bee hives maintained in hot and cool temperatures ?

Answer 3

In hot it is maintained at 35 degrees by water dumping= evaporative cooling. In cool temperatures they huddle to maintain temperature of 20 - 30 degrees which is essential for youth development.

Question 4

What two forms of heat loss/ gain cannot be used in aquatic animals and why ?

Answer 4

No evaporation due to the nature of the environment. No radiation as the water absorbs energy from the sun very well.

Question 5

Why do aquatic animals lose heat rapidly ?

Answer 5

As water has a high thermal capacity and high specific heat.

Question 6

Name and example of a thermoregulating fish and how it does so.

Answer 6

Tuna and mako sharks. They have a rete miracle system surrounding central muscles which uses a counter current exchange. Warm blood form this is transported around the body.

Question 7

How is the metabolic rate linked to ambient temperature in endotherms ?

Answer 7

metabolic rate increases as the temperature falls (shown by oxygen consumption.

Question 8

What happens to the metabolic rate of endotherms after temperatures rise past the thermoneutral zone ?

Answer 8

Metabolism starts to increase again.

Question 9

Name three ways endotherms increase metabolic rate.

Answer 9

1. Increased muscular activity (effective but can result in increase of convection heat loss)
2. Shivering involuntary and erecting hairs
3. NST- increase in metabolic rate without contraction of muscles.

Question 10

Where does NST occur ?

Answer 10

Brown adipose tissue (BAT)- fat cells. Most abundant in neonates.

Question 11

How is BAT different to WAT ?

Answer 11

BAT is much more vascularised.

Question 12

Name the four main ways endotherms keep warm ?

Answer 12

1. Increasing metabolic rate
2. Insulation
3. Posture changes
4. Avoiding harsh climates

Question 13

Why blubber instead of fur ?

Answer 13

Wet fur can increase heat loss by 20 fold.

Question 14

How do animals avoid harsh climates ?

Answer 14

Burrowing, hibernating, huddling and migrating.

Question 15

How may small mammals avoid high heat ?

Answer 15

Burrowing or being nocturnal.

Question 16

Name an animal that stores heat and how it is dangerous.

Answer 16

Desert ground squirrels store heat to 42.2 degrees and their lethal limit is 43. They do this until they re enter their burrows.

Question 17

How does panting in dogs work ?

Answer 17

When the dog is panting the nasal heat exchanger is bypassed. Toungue increases evaporative cooling during exhalation.