Homeostasis is a biological process that living organisms use to maintain their internal environment at an optimum range depending on the changes occurring in the external environment. The process of homeostasis is crucial because when some internal factors deviate further from the normal range body or the cells stop functioning properly. For instance, the liver plays a crucial role in maintaining the blood glucose within the optimum range. After consumption and digestion of diet rich in carbohydrates, the digestive system absorbs massive amounts of glucose which rapidly elevate blood glucose levels. Raised levels of blood glucose may lead to life-threatening problems such as hyperosmolar nonketotic hyperglycemic syndrome and ketoacidosis (Fujitani, 2017). To counteract the high levels of glucose, the pancreas produces a hormone known as insulin which stimulates the liver to take in excess glucose from the blood and convert it to glycogen lowering its level back to normal. During starvation, the level of glucose goes down which could also lead to complications such as a headache, blurred vision, dizziness, and confusion. Severe low blood glucose sometimes leads to a condition referred to as insulin shock. When levels of glucose go below the optimum range, the pancreas produces another hormone referred to as glucagon which stimulates liver to convert glycogen to glucose that is in turn released into bloodstream returning the blood glucose within the health range.
After homeostasis, a certain factor, for example, blood sugar level attains equilibrium such that it cannot go down or up. This new state of a particular factor within the internal environment is referred to as steady state. This state resists any forces that may result from external changes. In the event this new state is disturbed, the inbuilt regulatory organs respond to changes to generate a new equilibrium, a process referred to as feedback mechanism (Fujitani, 2017). A good example of a steady state is an internal environment of the cell where the ionic environment is maintained at non-changing concentrations by ions constantly moving across the plasma membrane.
So both the homeostasis and steady-state have the responsibility to maintain a constant internal environment to ensure body or the cells function normally. However, these two processes differ in a sense that homeostasis brings the internal conditions of the body back to the optimum range whenever they tend to deviate from normal range whereas steady state ensures that internal conditions remain constant despite the existence of external forces.
Most of the biological systems utilize negative feedback mechanism, a system that returns the involved factor back to the healthy range. It leads to a reduced effect of the initial stimulus. A good example of negative feedback system is thermoregulation where in case the body temperature exceed the normal range, the nerves in the brain and the skin send signal to the hypothalamus which in turn stimulate changes in effectors such as erector pili muscle and sweat glands to lower body temperature back to normal (KhanAcademy.com, 2017). Hypothalamus increase the rate of sweating and causes erector pili muscle to contracts, and all these changes lead to lowering of body temperature.
On the other hand in the positive feedback system, the output increases the effect of the initial stimulus. Positive feedback mechanism functions to amplify the initial signal until the intended action is effected. A perfect example is blood clotting system to control bleeding. In case a blood vessel is injured, platelets first clog on the site of injury where they release clotting factors that in turn attract more platelets (KhanAcademy.com, 2017). The process continues until a huge clot of platelets forms around the injured site, hence preventing further bleeding.
Fujitani, Y. (2017). Transcriptional regulation of pancreas development and β-cell function [Review]. Endocrine Journal, EJ17-0098.
KhanAcademy.com. (2017). Principles-of-physiology/body-structure-and-homeostasis. Khan Academy. Retrieved from https://www.khanacademy.org/science/biology/principles-of-physiology/body-structure-and-homeostasis/a/homeostasis