Short Answer Questions
1. Define homeostasis.
Homeostasis is the maintenance of a relatively constant internal environment.
2. Distinguish between obligatory and facultative losses.
Obligatory losses occur regardless of fluid intake, whereas facultative losses vary with fluid
intake and occurs in order to achieve water balance.
3. How does insensible perspiration differ from sweating? Do people without sweat glands still
experience insensible perspiration?
Insensible Perspiration Sweating
Pure water Electrolyte solution
Passive evaporation Active secretion
Entire skin surface Sweat glands
Continuous Activated by heavy work or high temperature
4. Compare the water content of a 250‐kg elite body builder and a 250‐kg amateur sumo wrestler, and
postulate why they might be different.
Although both individuals have a significant amount of muscle, due to the nature of their
activities and eating habits, the sumo wrestler would have amassed far more adipose tissue.
Since adipose tissue has very low water content, the sumo wrestler has less water than the
body builder even though they have the same body mass.
5. A group of geologists travel to the Himalayan Mountains to study rocks in the area. What effect would
these geologists experience in terms of fluid losses (if any)?
At high altitudes, the air is more dry. Therefore, the geologists would experience increased
passive evaporation (insensible perspiration) and especially increased water loss through the
MCQs TYPE A (one out of the following 5 choices is