Search results
Results from the WOW.Com Content Network
Thermogenesis is the process of heat production in organisms.It occurs in all warm-blooded animals, and also in a few species of thermogenic plants such as the Eastern skunk cabbage, the Voodoo lily (Sauromatum venosum), and the giant water lilies of the genus Victoria.
In shivering, the heat is the main intended product and is utilized for warmth. [citation needed] Newborn babies, infants, and young children experience a greater (net) heat loss than adults because of greater surface-area-to-volume ratio. As they cannot shiver to maintain body heat, [citation needed] they rely on non-shivering thermogenesis.
Additionally, almost all eutherian mammals (with the only known exception being swine) have brown adipose tissue whose mitochondria are capable of non-shivering thermogenesis. [8] This process involves the direct dissipation of the mitochondrial gradient as heat via an uncoupling protein, thereby "uncoupling" the gradient from its usual ...
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.
Both processes consume energy, however high-intensity shivering uses glucose as a fuel source and low-intensity tends to use fats. This is a primary reason why animals store up food in the winter. [citation needed] Brown adipocytes are also capable of producing heat via a process called non-shivering thermogenesis. In this process ...
Non-shivering thermogenesis is a regulated process in which the proton gradient generated by electron transport in mitochondria is used to produce heat instead of ATP in brown adipose tissue. [3] Animals that hibernate include bats , ground squirrels and other rodents, mouse lemurs, the European hedgehog and other insectivores, monotremes and ...
[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] Facultative endothermy can also be seen in multiple snake species that use their metabolic heat to warm their eggs.
The UCP1, or thermogenin, gene likely arose in an ancestor of modern vertebrates, but did not initially allow for our vertebrate ancestor to use non-shivering thermogenesis for warmth. It wasn't until heat generation was adaptively selected for in placental mammal descendants of this common ancestor that UCP1 evolved its current function in ...