What exactly produces and regulates body heat?

[seazal]

I read some Yogi can sleep naked at snow. Is there any scientific studies how they did it? Also what exactly regulate our body temperature? How much is the role of ATP in it?

 

[DrClaude]

I read some Yogi can sleep naked at snow. Is there any scientific studies how they did it?

There is no scientific study showing how they do it because they can't.

I'll let others answer the question you asked in the title.

 

[seazal]

Can the body ATP and blood flow enough to produce all the body heat?

Is there no more controversy about this.. and all is accounted for?

 

[jim mcnamara]

No controversy, no problem. If you got this idea from the internet please be aware that this forum serves people who want to discuss known science content in textbooks and scientific articles. Not speculation.

Mammals including humans regulate their body temperature - so we are homeothermic.
When you compare us to other cold blooded animals like reptiles, we burn about 10 times more calories per Kg of body weight. That difference is used to create body heat. It has great advantages, but the energy cost drives food requirements up drastically.

I do not know how much background you have, so try reading this:
https://en.wikipedia.org/wiki/Thermoregulation_in_humans

The simplest answer to your question: The heart, liver, and brain generate heat. Skeletal muscle generates heat when the muscles are active. Go for a run on a cool day, and you will break into a sweat. Skeletal muscles for body movement (running) generated the extra heat.

 

[tech99]

I read some Yogi can sleep naked at snow. Is there any scientific studies how they did it? Also what exactly regulate our body temperature? How much is the role of ATP in it?

I read that the indigenous peoples of Tierra del Fuego, maybe the Yamana people, who did not wear clothes, would roll their baby in the snow to warm them up. I am sure you will have experienced the rush of blood to the periphery when eventually you remove your hands from the snow.
Regarding heat regulation, our pupils are told that the body has negative feedback systems to achieve this. So for instance, additional cooling can be obtained by increasing peripheral blood flow and sweating. But engineers will say that regulation cannot be obtained with a simple negative feedback loop - it requires a control system, and that will require a setting point. How does the body obtain a setting point, or reference? Maybe by the peak in the action of enzymes at around 40C.

 

[jim mcnamara]

@tech99 - this is a more technical answer - discusses the pre-optic synapses of the hypothalamus in the brain as the primary control center.
https://www.sciencedirect.com/topics/medicine-and-dentistry/body-temperature-regulation

The set point temperature, T_set, is determined by a reference signal that is the constant FR of the temperature-insensitive neurons (I) (Figure 1.5) while the effector neurons receiving antagonistic excitatory and inhibitory signals from W and I function as an “error-comparator” for generating their adaptive neural output. The cold-sensitive neuron (C) is not cold-sensitive per se, but it is the inhibitory input from the warm-sensitive neuron (W) that provides it with cold-sensitivity. The thermosensitive neurons of POA also receive information on the body temperature from the spinal cord, via the brain stem. The set point temperature, T_set for effector neurons (w and c), is the temperature at which the excitatory and inhibitory inputs are balanced, and any change in the FR of W and I neurons will cause a shift in the T_set; when the FR increases, the T_set will be higher, and the contrary will happen when the FR decreases. Several internal and external stimuli that increase the FR of W and C neurons are known to lead to corresponding elevations of the T_set.

Please read the whole article, this quick quote is an answer to your set point question. It is based on neuron signaling from temperature sensitive neurons

Plus the link in my above post has some less technical explanation. HTH

 

[tech99]

Thank you for an extremely informative answer, of great interest. The set point mechanism is compensated for other factors altering firing rate.

 

[JamesPhD]

I read some Yogi can sleep naked at snow. Is there any scientific studies how they did it? Also what exactly regulate our body temperature? How much is the role of ATP in it?

So , I don't think anyone actually answered your question. The mechanism of thermogenesis is associated with mitochondria. In the oxidative phosphorylation system, the electron flow from an oxidised NADH through complexes I-V to generate ATP is coupled to proton pumping from across the intermembrane space. These protons enter through complex V to generate your ATP. This mechanism also produces your mitochondrial membrane potential However some protons instead enter through the uncoupled proteins UPR at the mitochondrial membrane and the free energy released is heat. This produces your body temperature. So its the fact these protons don't go into making any ATP that makes body temperature. From this, metabolism and mitochondrial bioenergetics is linked to body temperature and mechanisms which control metabolism regulate body temperature. Its all interconnected.

 

[jim mcnamara]

Okay. Good answer @JamesPhD . Thanks everyone for participating.The OP is no longer around, so time to lock the thread.