Final answer:
Dehydration through the skin and lungs does not take longer at altitude; it tends to occur more rapidly due to lower atmospheric pressure and often lower humidity, leading to increased respiration rates and skin evaporation.
Step-by-step explanation:
The statement that dehydration through the skin and lungs takes longer at altitude is false. Altitudes have a lower atmospheric pressure which means that the air is less dense and has lower oxygen content. This causes increased respiration rates to compensate for less oxygen, leading to greater water loss through expiration. Likewise, reduced humidity at higher altitudes can increase skin evaporation and moisture loss from the skin.
Under normal conditions, the body loses water through various mechanisms including skin evaporation, moisture in the air from the lungs, urine, and processes like sweating. However, factors such as environmental temperature, humidity, and altitude can affect the rate of water loss. On hot, dry days, sweat evaporates more quickly, cooling the body effectively. Conversely, high humidity can reduce evaporation rates, making it harder for the body to cool itself and leading to potential dehydration.
Additional water loss can occur in certain diseases, such as those involving diarrhea and vomiting, which can be particularly dangerous and lead to dehydration. Moreover, kidney diseases that increase urine output or fevers that raise insensible water losses can contribute to dehydration as well.