Energy Saving Mechanisms

Question 1

How does the marine iguana slow the rate it loses heat when it enters the water?

Answer 1

By slowing its heart rate

Question 2

What is heart rate hysteresis?

Answer 2

slowing heart rate to control temperature

Reverse hysteresis= increasing heart rate

Question 3

How is heat controlled in endothermic animals?

Answer 3

Increased basal metabolic rate 
Muscular activity 
Shivering 
Non-shivering thermogenesis 
Heat increment of feeding

Question 4

What is the most effective insulator in aquatic environments?

Answer 4

Blubber

Question 5

What is the difference between fur and elephant seals in temperature control?

Answer 5

If fur seals get too hot they have to go to the sea to cool down

Elephant seals are able to control the blood to go to the surface and dissipate heat- they can shut this off when they want to maintain heat

Question 6

What are peri-arterial venous retes?

Answer 6

An artery surrounded by a network of veins
Blood flows in one direction in the artery and the opposite direction in the veins where heat exchange takes place and prevents heat being lost from the animal

Question 7

What methods can be used to reduce energy expenditure?

Answer 7

Fasting 
Huddling 
Sleep
Torpor 
Hibernation

Question 8

What are the three phases to fasting?

Answer 8

1. Uses carbohydrate stores
2. Mainly fat metabolism (some protein)
3. Protein metabolism - starvation