Unit 9: Homeostasis, Heatstroke, and Hypthermia
In the previous unit we learned how the Second Law of Thermodynamics limits the efficiency of the body and other types of engines. If the thermal energy resulting from that inefficiency is not exhausted from the body then body temperature will increase and thermal injury may occur (and the same goes for engines). The ability of the body to exhaust heat depends on many factors, and the body uses several mechanisms to get it done. In this unit we will introduce those mechanisms and also analyze how body temperature changes in response to loss or gain of thermal energy. Regardless of the mechanism employed, the process of exhausting heat must satisfy the Second Law of Thermodynamics, so we will be sure to examine each mechanism through the lens of Entropy. The learner outcomes for this unit are listed below, and below that are some related key terms to watch out for as you complete the chapter.
Learning Objectives
- Explain how heat transfer by conduction, convection, radiation, and evaporation occur on a microscopic scale. [2]
- Explain strategies for slowing each type of heat transfer. [2]
- Apply the concepts of temperature, heat capacity, and latent heat to predict temperature changes in response to heat transfer. [3]
Key Terms and Concepts
Conduction
Phase change
Latent heat
transfer of heat due to the movement of fluid molecules driven by external factors other than thermal expansion.
Transfer of heat due to fluid movement caused by thermal expansion of the fluid
Electromagnetic radiation spontaneously emitted by all objects with temperature above absolute zero.
The amount of energy required to raise the temperature of an object by one temperature unit.
