Search results
Results from the WOW.Com Content Network
One form of homeostasis is thermoregulation. Body temperature varies in every individual, but the average internal temperature is 37.0 °C (98.6 °F). [1] Sufficient stress from extreme external temperature may cause injury or death if it exceeds the ability of the body to thermoregulate.
An early morning temperature higher than 37.3 °C (99.1 °F) or a late afternoon temperature higher than 37.7 °C (99.9 °F) is normally considered a fever, assuming that the temperature is elevated due to a change in the hypothalamus's setpoint. [15] Lower thresholds are sometimes appropriate for elderly people. [15]
A Q 10 of 1.0 indicates thermal independence of a muscle whereas an increasing Q 10 value indicates increasing thermal dependence. Values less than 1.0 indicate a negative or inverse thermal dependence, i.e., a decrease in muscle performance as temperature increases. [3] Q 10 values for biological processes vary with temperature.
Simplified control circuit of human thermoregulation. [8]The core temperature of a human is regulated and stabilized primarily by the hypothalamus, a region of the brain linking the endocrine system to the nervous system, [9] and more specifically by the anterior hypothalamic nucleus and the adjacent preoptic area regions of the hypothalamus.
The human body maintains a core body temperature at around 37 °C or 98.6 °F through mechanisms controlled by the thermoregulatory center within the hypothalamus.When the body is exposed to high ambient temperatures, intense physical exertion, or both, the thermoregulatory center will initiate several processes to dissipate more heat: [9] [11] [12]
In humans, hyperthermia is defined as a temperature greater than 37.5–38.3 °C (99.5–100.9 °F), depending on the reference used, that occurs without a change in the body's temperature set point. [3] [10] The normal human body temperature can be as high as 37.7 °C (99.9 °F) in the late afternoon. [2]
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation.
It may also occur from any condition that decreases heat production or increases heat loss. [1] Commonly, this includes alcohol intoxication but may also include low blood sugar, anorexia and advanced age. [2] [1] Body temperature is usually maintained near a constant level of 36.5–37.5 °C (97.7–99.5 °F) through thermoregulation. [2]