Describe the role of each in heat production: thyroxine, skeletal muscles, stress situations, and the liver. (p. 396)

Question: Explain the role of thyroxine, skeletal muscles, stress situations, and the liver in heat production. Answer: Thyroxine, a thyroid hormone, helps regulate metabolism and maintain body temperature by increasing the metabolic rate of cells, leading to greater heat production. Skeletal muscles generate movement and maintain posture, and the process of muscle contraction produces heat as a byproduct. In stress situations, the body releases stress hormones, increasing heart rate and overall metabolism, resulting in increased heat production. The liver, a major organ involved in metabolism, generates heat as a byproduct of its diverse metabolic functions, such as breaking down glucose and fatty acids for energy production.