Regulation of body temperature in warm blooded animals

[bryanl]

Why is it regulated so accurately?

And why, in almost all male mammals, do the testicles have to be kept cooler than the rest of the body, regardless of the animal's size or the climate of the habitat?

 

[bobsmith1492]

... because cellular division, movement of chemicals, and whatnot all perform optimally at said temperature, methinks?

 

[SuperFungus]

I have a closely related question, HOW does the body maintain it's temperature? Can someone explain the processes that maintain the heat to me? Outside of shivering/sweating of course.

 

[Gibsons]

Originally posted by: SuperFungus
I have a closely related question, HOW does the body maintain it's temperature? Can someone explain the processes that maintain the heat to me? Outside of shivering/sweating of course.

Most (all?) chemical reactions in a cell will generate some small amount of heat. They add up. When your muscles contract, you convert ATP to ADP and release a low wavelength photon (heat) or two. It's sort of analogous to friction.

 

[zinfamous]

Im not sure if all, but a good bit of body heat does come from ATP. But it's not just making ATP, but the other metabolic processes, Glycolosis, Krebs cycle, etc. Converting Glucose to energy (ATP), involves several heat releasing steps that do not create a molecule of ATP. I also believe that the physics of bloodflow works to generate and distribute heat as well. I know that this is how it works in Tuna and other large, high-performance ocean-dwelling creatures...but they aren't mammals and have a different circulatory system altogether.

Originally posted by: bryanl

And why, in almost all male mammals, do the testicles have to be kept cooler than the rest of the body, regardless of the animal's size or the climate of the habitat?

Meiosis (occuring within said balls) functions only at certain temperatures. That's why balls will hang low in the summer, and cling to the crotch in the winter. While standard body temps are optimal, that core temp isn't always maintained.

Main reasons taht the body needs to maintain ~98f temp is that DNA replication/transcription/translation occur at this temp, and to maintain a functional immune system. The beneficial bugs that inhabit your body thrive at ~98, while those that can do harm will attempt to lower your temp in order to survive. This is what a fever is--your body's natural repsonse to kill bugs by raising your core temp.

 

[f95toli]

Originally posted by: SuperFungus
I have a closely related question, HOW does the body maintain it's temperature? Can someone explain the processes that maintain the heat to me? Outside of shivering/sweating of course.

Basically by regulating the rate of the metabolic processes within our body. When it is cold we need to use quite a lot of energy just to keep warm (i.e. the body "burns" food to produce heat). This is one reason why it is important to eat and drink on a regular basis when you are outdoors when it is cold.
There are also some "emergency procedures" that the body can use, e.g. if the body notices that the temperature near your vital organs starts to drop it can respond by reducing the flow of blood to your extremeties in an attempt to reduce the rate of cooling (in extreme cases most of the blood will flow only through your brain and the vital organs).
Hence, if you (or more likely someone else) notices that your hands, feat,ears or nose have turned white you are in danger of serious frostbite.