Homeostasis And Endotherms

Introduction:

Homeostasis is the tendency of the body to seek and maintain equilibrium, a state of balance, within its internal environment. Endotherms are “warm blooded” animals that produce and maintain their own internal body heat. Most mammals and a few birds, are endotherms; this is beneficial because the enzymes in the body that carry out metabolic processes have an optimum temperature at which they function, having the body constantly be, or be close to, this optimum internal temperature means life processes never have to cease. The opposite of endotherms are ectotherms, animals such as reptiles and amphibians who do not regulate their own internal temperature and are ordinarily considered “cold blooded” because they do not produce
This occurs when the external temperature is very hot, either from physical exertion or over exposure to natural heat. Summer in Antarctica reaches temperatures of up to 15 degrees Celsius, however most of the time remains below 0 degrees Celsius. As the heat increases, the metabolic rate of the individual also increases, meaning the body will need more energy, ie. food, and liquid to maintain this faster rate of metabolism. This explains why during the summer emperor penguins live on the edges of the ice, diving for fish. However, if the temperature continues to rise, the body’s cells cannot function and enzymes carrying out life processes denature, ceasing metabolic activity. The individual will soon after die if the internal body temp is not reduced. To counter high temperatures and prevent themselves from suffering hyperthermia, emperor penguins have varying methods of reducing their internal body temperature. These methods include physiological responses such as gular fluttering, the fluttering of the throat to stimulate panting, which allows cool air to enter the lungs and cool them and the blood surrounding, as well as expelling warm air to give off heat. Vasodilation is another physiological response that allows a penguin to lose heat; the capillaries near the skin expand (dilate), increasing surface area, and warm blood is focused to the more exposed areas like around the mouth and the throat, or the feet. This allows heat to be lost to the surrounding environment and cools the blood. Countercurrent blood flow is also used to cool the blood this way, rather than warming it, as previously explained, heat is exchanged to the blood going to the skin, ie. the feet, and is lost into the ice or to the cool air this way. To reduce internal temperatures, emperor penguins also apply behavioural methods in cooling themselves, such as swimming - being