Can the human body's temperature be explained by bio-chemical mechanisms?

[Sparky_]

Greetings,

A curiosity –

I recall from school being shown the derivation (from quantum mechanics and statistical physics) the derivation for the PN silicon junction –

Along the same lines of thinking –

Can it be derived to show the human body’s temperature is 98.7 (or whatever the normal temp is)?

If so – how?

What are the bio-chemical mechanisms that give us our normal temperature of 98.7?

(I know very little about biology or bio-chemisrty - 1 course in high school and no further.)

Sparky_

 

[JaredJames]

Can it be derived to show the human body’s temperature is 98.7 (or whatever the normal temp is)?

If so – how?

Stick a thermometer up your backside, that will give you a fairly good result.

So far as deriving it goes, not sure what you mean. Your body regulates itself via various mechanisms to maintain a stable internal temperature.

The most obvious mechanism for temperature control is sweating.

 

[tiny-tim]

but surely there's a membrane somewhere that makes the decision?

 

[Andy Resnick]

but surely there's a membrane somewhere that makes the decision?

Membranes don't "make decisions".

That said, there are some models.

http://jap.physiology.org/cgi/content/full/100/4/1347

 

[tiny-tim]

http://jap.physiology.org/cgi/content/full/100/4/1347

uhh?

my membranes won't absorb all that! ​

 

[Sparky_]

What I mean is - can it be shown that the human body should be 98.7'ish

Meaning through statistical mechanics or the mechanics of the biological processes or thermodynamics, or ...? that the human body temp should be 98.7?

Let me clear up what I meant by the pn junction - in class we had worked with the exponential equation for a diode (and transistor) and used it and we approximated the drop across a forward biased pn junction at 0.7.

Then later in a physical electronics class it was derived including the constants and it was derived that the forward biased junction is approximately 0.7v. I recall thinking how cool it was that it could be derived.

Now we "use" (sorry - not really use but anyway) 98.7 for the human body's temp. I just think it would be cool if there was some way to show that number as a result from some calculations.

make sense?

Thanks
Sparky_

 

[Evo]

Normal average accepted body temperature reading is 98.6 F, or 37 C of course it varies.

 

[Andy Resnick]

What I mean is - can it be shown that the human body should be 98.7'ish

Meaning through statistical mechanics or the mechanics of the biological processes or thermodynamics, or ...? that the human body temp should be 98.7?

Let me clear up what I meant by the pn junction - in class we had worked with the exponential equation for a diode (and transistor) and used it and we approximated the drop across a forward biased pn junction at 0.7.

Then later in a physical electronics class it was derived including the constants and it was derived that the forward biased junction is approximately 0.7v. I recall thinking how cool it was that it could be derived.

Now we "use" (sorry - not really use but anyway) 98.7 for the human body's temp. I just think it would be cool if there was some way to show that number as a result from some calculations.

make sense?

Thanks
Sparky_

Biology has not yet advanced to the point where this is possible. However we *are*currently able to demonstrate from first principles that the measured transmembrane potential explains the difference between intracellular and extracellular concentrations of sodium and potassium; and more, the mechanism by which biochemical reactions exploit the free energy of ATP hydrolysis to drive biochemical reactions.

http://www.biologyjunction.com/chemiosmotic_theory.htm

 

[Andy Resnick]

uhh?

my membranes won't absorb all that! ​

It's simply a model designed to explain the origin of a thermal setpoint by combing certain sensors (heat-sensitive neurons and heat *insensitive* neurons) and feedback mechanisms/control loop. They also show data supporting the hypothesis.

 

[JaredJames]

the measured transmembrane potential explains the difference between intracellular and extracellular concentrations of sodium and potassium; and more, the mechanism by which biochemical reactions exploit the free energy of ATP hydrolysis to drive biochemical reactions.

My brain just melted!

Would I be right in thinking that it is possible for us to survive a variation of a few degrees either side of the required 37 degrees, but because our body reacts to any change it ends up causing more problems than it helps and puts us in danger?

Just a random thought there. Something that has always made me curious. There appear to be a number of situations our bodies reaction seems a bit overkill and harms us rather than helps us.

 

[tiny-tim]

Biology has not yet advanced to the point where this is possible.

Has it yet advanced to the point where it can identify the differences in cells that keep some animals, or certain organs in humans, at temperatures substantially lower than 98.6°?

 

[Pythagorean]

Has it yet advanced to the point where it can identify the differences in cells that keep some animals, or certain organs in humans, at temperatures substantially lower than 98.6°?

How do you mean? The arctic biology research lab here studies how animals survive the winter:

http://www.nytimes.com/2010/01/19/science/19creatures.html

Insects have evolved a variety of cryoprotective substances. As winter approaches, many freeze-tolerant insects produce high concentrations of glycerol and other kinds of alcohol molecules. These substances don’t prevent freezing, but they slow ice formation and allow the fluids surrounding cells to freeze in a more controlled manner while the contents of the cells remain unfrozen.

Unlike the protein antifreezes of other beetles, snow fleas and moths, the Upis antifreeze is a complex sugar called xylomannan that is as effective at suppressing ice growth as the most active insect protein antifreezes.

I can't find the research on a particularly interesting one, where it uses two different processes, allowing it's body to freeze almost completely without rupturing the cells, but using a solution with a lower freeze point in the head area so that it can eat or something (I really need to find that article...).

 

[tiny-tim]

The arctic biology research lab here studies how animals survive the winter:

http://www.nytimes.com/2010/01/19/science/19creatures.html

(is that the same Sean Carroll who writes on gravitation? )

I was really thinking of warm-blooded animals, that regulate their temperature, rather than cold-blooded ones that only cope with temperature.

 

[Pythagorean]

(is that the same Sean Carroll who writes on gravitation? )

I was really thinking of warm-blooded animals, that regulate their temperature, rather than cold-blooded ones that only cope with temperature.

Not sure about the article, it was just a google result. The actual research is done here in campus.

They do mammilian studies here, too, but there's no cool antifreeze so it's never talked about (hibernation = boring, I guess).

 

[Andy Resnick]

Has it yet advanced to the point where it can identify the differences in cells that keep some animals, or certain organs in humans, at temperatures substantially lower than 98.6°?

In addition to Pythagoran's post regarding 'antifreeze proteins', there is a lot of research on hibernation: PubMed pulled up 500 review articles, and another 5000 research papers. Long story short, we don't know. There's also a lot of articles regarding the thermoprotective role of shivering and cold adaptation.

But I wonder if you are talking about two different phenomena- either thermal regulation of an organism (i.e. thermal homeostasis), or the metabolic rate (heat generation) of particular cells. It's not clear there are causal relations between the two: for example, during hibernation metabolism slows, but AFAIK the transmembrane potential remains unchanged at about 60mV.

 

[Andy Resnick]

My brain just melted!

Would I be right in thinking that it is possible for us to survive a variation of a few degrees either side of the required 37 degrees, but because our body reacts to any change it ends up causing more problems than it helps and puts us in danger?

Just a random thought there. Something that has always made me curious. There appear to be a number of situations our bodies reaction seems a bit overkill and harms us rather than helps us.

Our bodies maintain very tight control over their external environment (the extracellular milieu). Not only is temperature controlled, but so is pH, the osmolarity, and the concentrations of specific ions.

AFAIK, homeostatic mechanisms work via negative feedback loops- positive feedback loops are less stable. Certainly, automimmune diseases can be thought of as a positive feedback loop.

 

[JaredJames]

Our bodies maintain very tight control over their external environment (the extracellular milieu). Not only is temperature controlled, but so is pH, the osmolarity, and the concentrations of specific ions.

AFAIK, homeostatic mechanisms work via negative feedback loops- positive feedback loops are less stable. Certainly, automimmune diseases can be thought of as a positive feedback loop.

So how much damage would occur to our body if the internal temperature dropped by 2 degrees celsius and our bodies didn't react to it (hypothermia didn't set in)?

And to add, how much damage would occur if internal temperature dropped by 5 degrees and we didn't react?

 

[Andy Resnick]

So how much damage would occur to our body if the internal temperature dropped by 2 degrees celsius and our bodies didn't react to it (hypothermia didn't set in)?

And to add, how much damage would occur if internal temperature dropped by 5 degrees and we didn't react?

I'm not sure I understand what you are getting at. For example, doing as you suggest is used deliberately in certain surgeries:

http://www.nejm.org/doi/full/10.1056/NEJMoa040975

While the same situation can also have adverse effects:

http://www.anesthesia-analgesia.org/content/95/5/1381.full

 

[JaredJames]

When your body temperature drops, hypothermia (or with an increase, hyperthermia) sets into protect you.

But I see those two as potentially doing more damage than good. So I'm asking if hypothermia kicking in when your core temperature drops, say 5 degrees celsius, is truly required? Would we really suffer damage if it didn't kick in until our core temperature dropped by 10 degrees?

 

[Andy Resnick]

When your body temperature drops, hypothermia (or with an increase, hyperthermia) sets into protect you.

But I see those two as potentially doing more damage than good. So I'm asking if hypothermia kicking in when your core temperature drops, say 5 degrees celsius, is truly required? Would we really suffer damage if it didn't kick in until our core temperature dropped by 10 degrees?

Hypothermia is not a protective response- hypothermia is a pathophysiological state. Shivering is a protective response.

 

[JaredJames]

So it isn't a defensive measure? Didn't know that.

 

[G037H3]

whenever my body temp is measured, it's 97.2F
should I be worried? >_>

 

[bobze]

whenever my body temp is measured, it's 97.2F
should I be worried? >_>

No, the operative word in "average body temperature" is "average". That 98.6 is only an average. It depends on, as someone above pointed out, the elevation, where the reading is made, the body type the person has, the age and many other factors.

There is lots of variation between individuals with body temperature.

 

[Jack the Stri]

For starters, higher temperatures allow higher reaction rates. Most enzymes in our body have been optimised to work at about 37° C. Of course you could wonder why we aren't even hotter then, but a) protein stability decreases with temperature, b) we'd suffer quite high energy losses to the environment, thus being an inefficient system.