NONSHIVERING THERMOGENESIS Meaning and
Definition
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Nonshivering thermogenesis is a physiological process in which heat production is regulated outside of the normal muscle shivering response. It involves the activation of specialized brown adipose tissue (BAT) to generate heat in order to maintain body temperature in certain mammals, including humans.
Typically, when the body is exposed to cold temperatures, shivering is the main mechanism used to generate heat. However, nonshivering thermogenesis occurs in situations where shivering alone is insufficient to meet the thermal requirements. This process is primarily controlled by a hormone called norepinephrine, which is released from nerve terminals into the brown adipose tissue.
The BAT is responsible for nonshivering thermogenesis because it contains a high concentration of mitochondria, which are the powerhouses of cells that produce energy. These mitochondria in brown adipocytes contain a unique protein called uncoupling protein 1 (UCP1). UCP1 allows protons to flow freely across the mitochondrial membrane, uncoupling the respiratory chain from ATP synthesis. As a result, the energy that would have been used to generate ATP is released as heat.
Nonshivering thermogenesis is an important mechanism for body temperature regulation, particularly in newborns and hibernating animals. In newborns, BAT plays a crucial role in maintaining body temperature due to their relatively large surface area-to-mass ratio and limited ability to shiver. Additionally, nonshivering thermogenesis is thought to have potential implications for metabolic disorders such as obesity and diabetes, as it can increase energy expenditure and thus impact body weight regulation.
Etymology of NONSHIVERING THERMOGENESIS
The word "nonshivering thermogenesis" can be broken down into three components:
1. "Non-" is a prefix in English meaning "not" or "without".
2. "Shivering" is the gerund form of the verb "shiver", which means to tremble or shake involuntarily due to cold or fear.
3. "Thermogenesis" is derived from the Greek words "thermos" meaning "heat" and "genesis" meaning "origin" or "production".
Therefore, the etymology of "nonshivering thermogenesis" suggests a process that produces heat without the mechanism of shivering, referring specifically to the physiological process of generating heat in warm-blooded animals without muscular tremors.
