Lecture 14 Flashcards
How do endothermic animals produce heat?
. Increased nasal metabolic rate . Muscular activity . Shivering . Non-shivering thermogenesis . Hear increment of feeding
How do endotherms reduce heat loss?
. Size . Insulation - fur/ feathers - blubber . Countercurrent heat exchangers
What are the methods of reducing energy expenditure?
. Fasting . Huddling . Sleep . Torpor . Hibernation
What are the three things ectotherms use to regulate body temperature?
. Morphology
. Behaviour
. Physiology
What is vasoconstriction?
Is where the vessels in the periphery of the animal shut down
What is vasodilation?
Is where vessels in the periphery of the animal open up
How does the opening up and closing down if the vessels in the periphery of an animal influence it’s heart rate?
When they open up is when the heart rate is high and when they close down is when the heart rate is low
When a marine iguana goes into water what does it do to keep the temperature of the core warm?
It has vasoconstricts the blood vessels in surrounding tissues essentially making its insulation layer thicker keeping the temp to the core of the animal. It is not pumping blood into the skin
When a marine Iguana goes into water why is it not pumping blood into the skin?
Because that has contact with the cold water, so it is trying to avoid the warmed up blood from it sitting in the sun and keep it for the core
When marine Iguanas come out of the cold water what do they do?
They soak up the solar radiation and open the vessels in the skin and vasodilate
When marine iguanas come out of the water they vasodilate, why is this?
Means that cold or cooled blood is then circulated into the skin where it comes into close proximity with the environment and with the solar radiation
What are the ways of heat production in ectothermic animals?
. Increased basal metabolic rate . Muscular activity . Shivering . Non-shivering thermogenesis . Heat increment of feeding
Tuna are fast, constant swimming fish so what do they need to do to be efficient? How do they do this?
To be efficient then all the muscles should be kept at a constant temperature. So they can adapt all the enzymes that are used within that muscle to an optimum temperature (which you can’t do if your overall muscle and cardiovascular system is like a normal fish)
How to endothermic animals produce heat?
. Muscular activity
. Shivering
. Non-shivering thermogenesis
. Heat increment of feeding
How do endothermic reduce heat loss?
. Size . Insulation - fur/ feathers - blubber . Countercurrent heat exchangers
What is the best insulator?
Air
Air is the best insulator but only as long as what?
You can maintain that air layer, is you lose the air in the fur then you lose your insulation entirely
Why doesn’t the sea otter lose it’s insulation when it’s fur gets wet but all the others do?
This is because it has an incredibly dense underfur and even if it is wet the water still can’t get into this layer and it still maintains its structure retaining the air and insulation
Other than working as insulation what other proposed blubber have that makes it useful?
It is a potential source of energy because it is essentially fat
What is the problem with having fur as an insulator?
It is a physical barrier
How are animals with blubber able to modify their insulation?
By cardiovascular control
Give a difference between blubber and fur
Blubber is a living tissue
Explain how animals with blubber control their body temperature
Blubber is a living tissue so it has a blood supply that goes into it.
Their heart rate changes because they have control of the blood supply to the periphery
Animals that have blubber control their temperature by controlling their blood supply to the periphery. How do they do this if it is too hot?
It opens up the blood vessels and allows the heat to escape through the blubber so the blood vessels that are very close to the surface radiate heat
