Chapter 9: Humans in the Desert
Maintaining water and salt balance
Dehydration and Hyperthermia
Dehydration and its symptoms
Hyperthermia and its symptoms
Developmental compensation and acclimation
Human History in the Desert
Human utilization of desert resources
Desertification describes the degradation of semiarid grasslands at the desert's edge. United States Geological Survey.
1. a) Describe the thermal budget of a human. This may be answered in the form of a diagram. b) Humans can regulate body temperature by both physiological and behavioral means. Describe the physiological mechanisms humans have to prevent hyperthermia.
2. Osmoregulation maintains the body's water and salt balance. a) Describe the essential role kidneys play in osmoregulation. b) Describe the danger of salt loss and depletion and how this can promote dehydration.
3. Dehydration can be simply an annoyance when mild but can be deadly when extreme. Describe the course of increasing dehydration. Include both the physiological phenomena and the symptoms exhibited. While you may want to include how dehydration is related to hyperthermia, a complete description of heat syncope, heat stroke, and heat cramps is not necessary. (see the question below)
4. Describe the following illnesses: heat syncope, heat stroke, and heat cramps.
5. How is it that clothing can have a cooling effect for someone exposed to extreme heat and intense sun in the desert?
6. Human survival in the desert can be enhanced by acclimatization. Describe how humans acclimate to the desert.
7. Define desertification and describe the mechanisms by which humans bring about such changes.
8. The arid Southwest is a hotspot for threatened and endangered species in North America. a) What are the major causes of species endangerment in deserts? b) A partial explanation for the vulnerability of desert species may be that there are many endemic species in the desert. Explain how endemism might promote endangerment in the arid Southwest.