Temperature Control and Balance
Thursday, February 14, 2008 by Tansa
In the human body also animal, there is a system to regulate and control temperature. In mammals --warm-blooded animals-- the optimum temperature is approximately 37.5 degrees C (98.6 degrees F). This means that although the external temperature may vary greatly from place to place and time to time, the body has mechanisms to compensate for the variations.
On Earth, the temperature has been measured below -60 degrees C in Arctic conditions and above 60 degrees C in desert conditions. The greatest variation in internal body temperature consistent with cellular life is around +- 4 degrees C, so if body temperature were to rise and fall with external temperature, the cells would soon die.
In the brain, specifically the hypothalamus, there is a temperature monitoring device somewhat like the thermostat that I described earlier. This receives input from temperature receptors (thermometers) scattered throughout the body, both on the skin and in internal organs.
If the hypothalamic `temperature centre' detects that the body temperature is too high i.e. greater than 37.5 degrees C, then cooling processes are activated. These include diverting blood nearer to the body surface which allows the excess of heat to be lost to the environment. In addition, sweat glands are activated which produce perspiration which evaporates and cools the skin. Also, the body's metabolic rate (rate at which food is being burned) is decreased so less heat is produced.
If the `temperature centre' detects that the body temperature is too low, the systems of heat conservation are set into motion. These include diverting blood away from the surface to prevent further heat loss, effecting the burning of food stores, the mechanisms of shivering and teeth-chattering to generate heat by movement and the concurrent production of heat-generating hormones. There are many problems associated with either extreme of body temperature. If it is too high, it leads to a state of dehydration, heat exhaustion, heat stroke etc. Conversely, if body temperature is too low, the resulting hypothermia is associated with cell death and heart problems. It is obvious that the issue of water control balance is also closely linked to temperature control so this is a good example of the integration of balancing systems within the human body.
