Answer
Shivering thermogenesis is a reflex alternating contraction of small pairs of antagonistic muscles in response to low body temperature. It is a process that involves the generation of heat from ATP, and can increase the rate of body heat production several-fold.
Nonshivering is also a physiological mechanism that helps in maintaining temperature homeostasis. This is however acts/operates over a longer time period than shivering thermogenesis. Exposure to cold ambient conditions over a long period (weeks) stimulates the sympathetic nervous system. The increase in ANS activity has the effect of raising the metabolic rate (MR). This means that the body uses more calories, appetite increases, and more nutrients are consumed.
Work Step by Step
In this adaptation the metabolic rate may be raised higher by 30 to 50%; this facilitates the maintenance of body temperature around the set point.
