Question

Evaporative cooling is one of several processes that contributes to homeostasis in endotherms.
Which of the following describes the thermodynamic principle behind this process?

• A. As a phase change, evaporation of water absorbs heat, drawing heat energy out of the body.
• B. The heat that is generated naturally transfers from the system (organism) to the surroundings providing evaporative cooling effect.
• C. The evaporation of sweat is an exothermic process that favors the transfer of heat from the organism to the surroundings.
• D. Cooling is achieved by the secretion of sweat.

Answer 1

The correct option is A As a phase change, evaporation of water absorbs heat, drawing heat energy out of the body.

• Sweating causes a decrease in core temperature through evaporative cooling at the skin surface. As high energy molecules evaporate from the skin, releasing energy absorbed from the body, the skin and superficial vessels decrease in temperature. Hence, Evaporative cooling is one of several processes that contribute to homeostasis in endotherms as a phase change, evaporation of water absorbs heat, drawing heat energy out of the body.

So, the correct answer is 'As a phase change, evaporation of water absorbs heat, drawing heat energy out of the body.'.