You can mark you interesting snippets of text that will be available through a unique link in your browser.


warm-bloodedness

warm-bloodedness

* * *

also called  Homoiothermy,  also spelled  Homeothermy,  

      in animals, the ability to maintain a relatively constant internal temperature (about 37° C [99° F] for mammals, about 40° C [104° F] for birds), regardless of the environmental temperature. The ability to maintain an internal temperature distinguishes these animals from cold-blooded, or poikilothermic, animals, which usually have about the same temperature as their environment. Warm-blooded animals are able to remain active in situations in which cold-blooded ones cannot. Body temperatures of homoiotherms are kept at a constant value by regulatory mechanisms that counteract the effects of the external environment. In cold environments, regulatory mechanisms maintain body temperature by increasing heat production and decreasing heat loss. In hot environments, regulatory mechanisms maintain body temperatures by increasing heat loss. Within a neutral range of several degrees (27° to 31° C [81° to 88° F] for man), neither heat gain nor heat loss is necessary to maintain body temperature.

      Shivering, a regulatory mechanism of many warm-blooded animals, increases heat production. hibernation, another mechanism used by certain warm-blooded animals, decreases heat loss by means of a general slowing-down of bodily functions. panting and perspiring are mechanisms for increasing heat loss.

* * *


Universalium. 2010.

  
Share  

Look at other dictionaries:

  • warm-bloodedness — noun see warm blooded …   New Collegiate Dictionary

  • warm-bloodedness — noun the state of being warm blooded …   Wiktionary

  • Warm-blooded — In biology, a warm blooded animal species is one whose members maintain thermal homeostasis; that is, they keep their body temperature at a roughly constant level, regardless of the ambient temperature. This involves the ability to cool down or… …   Wikipedia

  • bloodedness — noun The quality of having blood of a particular kind, as in warm bloodedness, full bloodedness …   Wiktionary

  • warm-blooded — adjective Date: 1793 1. having warm blood; specifically having a relatively high and constant internally regulated body temperature relatively independent of the surroundings 2. fervent or ardent in spirit • warm bloodedness noun …   New Collegiate Dictionary

  • cold-bloodedness — See cold bloodedly. * * * ▪ zoology also called  Poikilothermy, Ectothermy, or Heterothermy,         the state of having a variable body temperature that is usually only slightly higher than the environmental temperature. This state distinguishes …   Universalium

  • Physiology of dinosaurs — Note: In this article dinosaur means non avian dinosaur, since most experts regard birds as an advanced group of dinosaurs. The physiology of dinosaurs has historically been a controversial subject, particularly thermoregulation. Recently, many… …   Wikipedia

  • dormancy — /dawr meuhn see/, n. the state of being dormant. [1780 90; DORM(ANT) + ANCY] * * * ▪ biology Introduction       state of reduced metabolic activity adopted by many organisms under conditions of environmental stress or, often, as in winter, when… …   Universalium

  • Evolution of mammals — Restoration of Thrinaxodon, a member of the cynodont group, which includes the ancestors of mammals Further information: Evolutionary history of life The evolution of mammals within the synapsid lineage (sometimes called mammal like reptiles )… …   Wikipedia

  • Dinosaur renaissance — Robert Bakker (right) teaching at the Houston Museum of Natural Science The dinosaur renaissance[1] was a small scale scientific revolution that started in the late 1960s, and led to renewed academic and popular interest in dinosaurs. It was… …   Wikipedia