Search results
Results from the WOW.Com Content Network
In addition, shivering also signals the body to produce irisin, a hormone that has been shown to convert white fat to brown fat, which is used in non-shivering thermogenesis, the second type of human thermogensis. [27] Non-shivering thermogenesis occurs in the brown fat, which contains the uncoupling protein thermogenin.
The low demands of thermogenesis mean that free fatty acids draw, for the most part, on lipolysis as the method of energy production. A comprehensive list of human and mouse genes regulating cold-induced thermogenesis (CIT) in living animals or tissue samples has been assembled [15] and is available in CITGeneDB. [16]
On the other hand, huddling allows emperor penguins (Aptenodytes forsteri) to save energy, maintain a high body temperature and sustain their breeding fast during the Antarctic winter. [12] This huddling behaviour raises the ambient temperature that these penguins are exposed to above 0 °C (at average external temperatures of -17 °C). [ 12 ]
Further examinations of animals traditionally classified as cold-blooded have revealed that most creatures manifest varying combinations of the three aforementioned terms, along with their counterparts (ectothermy, poikilothermy, and bradymetabolism), thus creating a broad spectrum of body temperature types.
Homeothermy could have helped compensate for the reduced oxygen availability, ensuring efficient oxygen utilization and overall metabolic function. Migratory Patterns: Animals that migrated long distances would have encountered a wide range of temperature conditions. Homeothermy could have evolved as a way to maintain energy-efficient migration ...
An ectotherm (from the Greek ἐκτός (ektós) "outside" and θερμός (thermós) "heat"), more commonly referred to as a "cold-blooded animal", [1] is an animal in which internal physiological sources of heat, such as blood, are of relatively small or of quite negligible importance in controlling body temperature. [2]
Vasomotor responses allow control of the flow of blood between the periphery and the core to control heat loss from the surface of the body. Lastly, the organism can show insulation adjustments; a common example being "goosebumps" in humans where hair follicles are raised by pilomotor muscles, also shown in animals' pelage and plumage. [4]
The honey bee, for example, does so by contracting antagonistic flight muscles without moving its wings (see insect thermoregulation). [18] [19] [20] This form of thermogenesis is, however, only efficient above a certain temperature threshold, and below about 9–14 °C (48–57 °F), the honey bee reverts to ectothermy. [19] [20] [21]