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Goose bumps are created when tiny muscles at the base of each hair, known as arrector pili muscles, contract and pull the hair straight up. The reflex is started by the sympathetic nervous system, which is responsible for many fight-or-flight responses. The muscle cells connected to the hair follicle have been visualized by actin ...
Thus, to Barcroft homeostasis was not only organized by the brain—homeostasis served the brain. [12] Homeostasis is an almost exclusively biological term, referring to the concepts described by Bernard and Cannon, concerning the constancy of the internal environment in which the cells of the body live and survive.
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.
Goosebumps have a practical purpose for animals. When an animals’ hair sticks up it makes it look bigger and helps protect it against predators. A raised layer of fur can also help keep an ...
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.
Located in the posterior hypothalamus near the wall of the third ventricle is an area called the primary motor center for shivering. [citation needed] This area is normally inhibited by signals from the heat center in the anterior hypothalamic-preoptic area but is excited by cold signals from the skin and spinal cord. Therefore, this center ...
The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. [1]: 8.1 Metabolic pathways depend upon enzymes to catalyze individual steps.
These are known as facultative or exercise endotherms. [17] 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 ...