Interdependent Preoptic Osmoregulatory and Thermoregulatory Mechanisms Influencing Body Fluid Balance and Heat Defense

Excerpt

Maintenance of core body temperature within narrow bounds and the constancy of composition and volume of body fluids in mammals are probably the most iconic manifestations of homeostasis in mammals. The ability to keep the internal environment of their bodies as unchanged as possible in the face of hostile environments is one of the reasons for mammals being able to populate and survive in many regions of the planet. Whereas mammals that inhabit the cooler and temperate regions of the earth are less likely to experience extremes of high ambient temperatures or insufficient supply of water for maintaining bodily hydration, this is not the case for those species that exist in warmer and drier parts of the earth. The evolutionary emergence and survival of many mammalian species has resulted from adaptations that permit such animals to minimize and correct changes in core body temperature as well as deficits in body fluid volume and composition arising in hot, dry environments.