Why warm blooded animals cannot tolerate the mixing of oxygenated and deoxygenated bloo d
Answers
Answer:
Given below
Explanation:
The animals we consider to be *warm-blooded use up more energy in heat production (even when resting) and consequently have higher metabolic needs, so this requires a more efficient oxygen supply to their body tissues to keep up. Having a four chambered heart makes this possible because it enables the animal to maintain two separate pressure levels in its blood: A low pressure circuit going to and from the lungs and a higher pressure circuit going to the rest of the body, enabling the heart to pump oxygen rich blood to the tissues more quickly.
The separation of oxygenated and deoxygenated blood in the four chambered heart also means the blood going to the tissues has a richer oxygen supply than the mixed/diluted blood that results from having a three chambered heart.
There is one group of ‘cold blooded’ animals that does have a four chambered heart: The crocodilians (alligators, crocodiles and their kin). In fact, the crocodilian heart is highly sophisticated even compared to our mammalian heart, with extra valves and openings that enable to crocs to do some amazing shunting tricks while diving, but that’s a whole other story in itself.
Interestingly, the crocodilians’ four chambered heart is one of the supporting bits of evidence for the hypothesis that the archosaur common ancestor of crocodilans, dinosaurs (and therefore birds) and pterosaurs was warm-blooded.
*The terms ‘warm-blooded’ and ‘cold-blooded’ are actually misleading, for most reptiles have very warm blood during the day, for they bask to keep it that way. I prefer the terms endotherm (animals which produce their own heat, like mammals, birds and some others) and ectotherm (animals which source their heat externally, like most fish, amphibians and reptiles).