What is Homeostasis?
The word Homeostasis arises from two Greek words, Homeo means same and Stasis means stable, is a state of equilibrium especially in the physiological systems of higher animals, achieved by a self-regulating system. This state of equilibrium is a condition called dynamic equilibrium in which continuous change occurs but at last uniform conditions are attained. The term was first used by Walter Cannon in 1926. It is characteristic of a system which helps maintain stable and relatively constant internal environment which is optimal for survival.
Examples of homeostasis include maintaining a constant body temperature in animals and the concentrations of sodium and calcium ions in blood plasma. In humans normal body temperature is around 37 °C but many factors like hormones, disease or metabolic rate can affect its normal value.
How Homeostasis is Achieved
When body temperature rises above normal then sweating, a natural cooling process brings it down to normal by making skin more moist and available for evaporation. In contrast, when body temperature lowers down, heat loss is reduced by reducing blood circulation. Thus, any change which turns up or down the temperature automatically triggers negative feedback. Negative feedback does not mean bad but it means a reaction opposite to what is already going on.
Flushing is another automatic response of the body to overheating, in which small blood vessels expand allowing more blood near the skin where it can cool, making skin more reddish in color. Thermogenesis is a response to excessive cold causing involuntary skeletal muscle contractions and burning body fat to produce more heat.
Importance of Homeostasis
Homeostasis is an automatic and inevitable process if the system is functioning well. It is a key to life, if homeostasis is not successful, it can lead to diseases like hypertension and diabetes and in worst situation it can cause a risk to life.