View Single Post
  #16  
Old 06-10-2009, 06:24 AM
Blake Blake is offline
Member
 
Join Date: Mar 2001
Posts: 11,049
Outliern you are completely misunderstanding your references. They are just saying that that the body regulates its temperature primarily via the skin. That's not surprising since that's where it has the most contact with the external world. In order to achieve that regulation there are of course temperature sensors in the skin itself.

What they are not saying is that the body's “thermostat”, ie the primary switch that regulates temperature, is in the skin. In fact one of your own references states explicitly that “The hypothalmus contains … the control mechanisms [and] the key temperature sensors”

In more detail, the first reference is referring strictly to the control of sweating. And it notes that the whole process is under the control of the hypothalamus. The skin sensors control only the amount of sweat produced, not the temperature of the body itself. The second reference merely notes that there are temperature sensors in the skin associated with temperature regulation, but once again it notes the whole process is under the control of the hypothalamus.

I can go into a lot more detail on this subject if you’d like, but for now I just want to stress that the body definitely does not regulate temperature based on skin temperature. Thank Og, since skin temperature routinely fluctuates wildly minute to minute, but your systems will start to crash if the core temperature varies by more than ~3^oC.

There’s a reason why body temperature is taken in the mouth, anus or ear rather than being held between the skin in the fingers: it’s because skin temperature varies widely and rapidly, whereas core temperature is stable except under condition s of ill health. If the body keyed its temperature to skin temperature then you would start shivering when you skin temperature dropped below 37^oC, which occurs at an air temperature of about 22o^C. Similarly when you entered the sun and your skin temperature reached 38o^C you’d start sweating, even tough air temperature was only15o^C.

Just to keep things clear: the overriding control of body temperature is undertaken by the hypothalamus, and the key temperature sensors are all located in the hypothalamus. The skin contains minor sensors that assist in fine regulation heat dispersal/retention when the hypothalamus seems that to be necessary. But in now way s the body’s temperature keyed to the skin temperature. That would be rapidly fatal because skin temperature fluctuates precisely because it is the site of heat dispersal/absorption.