Search results
Results from the WOW.Com Content Network
The thermosphere (or the upper atmosphere) is the height region above 85 kilometres (53 mi), while the region between the tropopause and the mesopause is the middle atmosphere (stratosphere and mesosphere) where absorption of solar UV radiation generates the temperature maximum near an altitude of 45 kilometres (28 mi) and causes the ozone layer.
The lower part of the thermosphere, from 80 to 550 kilometres (50 to 342 mi) above Earth's surface, contains the ionosphere. The temperature of the thermosphere gradually increases with height and can rise as high as 1500 °C (2700 °F), though the gas molecules are so far apart that its temperature in the usual sense is not
The ability to maintain homeostasis at varying temperatures is the most important characteristic in defining an endothermic eurytherm, whereas other, thermoconforming eurytherms like tardigrades are simply able to endure significant shifts in their internal body temperature that occur with ambient temperature changes. [21]
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.
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.
Sufficient stress from extreme external temperature may cause injury or death if it exceeds the ability of the body to thermoregulate. Hypothermia can set in when the core temperature drops to 35 °C (95 °F). [2] Hyperthermia can set in when the core body temperature rises above 37.5–38.3 °C (99.5–100.9 °F).
Thermotolerance is the ability of an organism to survive high temperatures. An organism's natural tolerance of heat is their basal thermotolerance . [ 1 ] Meanwhile, acquired thermotolerance is defined as an enhanced level of thermotolerance after exposure to a heat stress.
In physiology, thermoception or thermoreception is the sensation and perception of temperature, or more accurately, temperature differences inferred from heat flux.It deals with a series of events and processes required for an organism to receive a temperature stimulus, convert it to a molecular signal, and recognize and characterize the signal in order to trigger an appropriate response.