What prevents water loss in animals?
Water loss is a response to several everyday activities. For example, eating salty food will generally lead to more excretion via the kidneys, while physical activity or excess heat will lead through water loss via transpiration. For healthy people the best response is to drink sufficient water so that the normal loss of water from a normal diet and activity level does not lead to dehydration. In some cases there is a pathophysiology and in those cases synthetic hormones of anti-diuretic hormone could be used.
What functions as a protective covering that resists harmful substances and organisms and prevents extreme water loss?
Which organ system is used as a waterproff barrier that blocks the entrance of pathogens into the body and loss of water from the body?
Urination, defecation (there is some water in stools), skin loss (sweat), and exhalation loss (there is water in exhaled breath). Desert animals, such as camels, can cut these losses significantly. For menstruating females, add the water content of the expelled blood. For those with asthma or colds, add nasal loss.