Homeostasis – Meaning and 4 examples of Homeostasis
The human body is a physiological structure and a living system. As a living system, it consists of an internal and external environment, between which information and matter are continuously exchanged. The internal environment consists of fluids.
The internal environment, therefore, must be kept constant for the health, growth, development and proper functioning of the body. The body system has to produce a dynamic balance or steady-state even in the phase of change.
What is Homeostasis?
The term homeostatic was coined in 1930 by the physician Walter Cannon. His book, The Wisdom of the Body, describes how the human body maintains steady levels of temperature and other vital conditions such as the water, salt, sugar, protein, fat, calcium and oxygen contents of the blood.
Simply, homeostasis can be defined as the steady-state within the body; the stability of the internal environment. It is the ability to live things to regulate its internal environment and keep it in a stable state by frequently adjusting to changes in the physical and chemical conditions of its fluid.
These conditions are temperature, hydrogen ion concentration, osmotic pressure, dissolved substances in the blood fluid-like oxygen, urea, food substances.
The following are organs of the body that play vital roles on homeostasis. They are the kidney, liver and skin. But the brain is the key controller of the homeostasis process.
(a) The kidney functions as a homeostatic organ by regulating the amount of blood that leaves them by removing excretory waste like urine and controlling the amount of water, salts and acids in the body.
(b) The liver functions as homeostatic by regulating the nutrient level in blood especially blood glucose level. The glucose level is controlled by the hormones known as insulin, glucagon and glucocorticoids. It also stores excess glucose in form of glycogen. It breaks down red blood cells, it stores vitamins and minerals. It deaminates excess amino acid to form urea.
(c) The skin’s homeostatic function is temperature control by getting rid of excess heat by sweating and conserving heat by producing less sweat.
The Homeostasis Process:
The homeostasis process is a feedback process. This means that there is a regulation of a process by the results or products of that process. It starts from receiving stimuli from the brain to detection, then it gets to the controller/ effector which produces the result.
Examples of Homeostasis
1. Regulation of internal temperature: This is one vital example of homeostatic. Temperature is the degree of hotness or coolness of the human body. A healthy person maintains 98.6 degrees Fahrenheit (37 degrees Celsius). In case of change from the normal body, temperature sweating occurs(overheating).
Here, the body produces moisture on the skin that eventually evaporates. In cold weather, the body shivers. This is an example of homeostatic. It is pertinent to know that the body’s temperature regulation is controlled by a region in the brain called the hypothalamus. The skin plays a vital role in regulating the body’s temperature.
2. Proper regulation of water: Water is very necessary for us as living things. Our survival depends on it. During cold weather, if we take enough water we sweat less and urinate. When the weather is hot, we lose water from the body through sweating, then we urinate less. The body has been able to maintain balance even when there is change.
3. The digestion process and excreting process: Digestion is the ability of food to be broken down into simple, soluble and diffusible substances. The ability of the digestive system to act on all types of food eaten into the stomach is an accurate example of homeostasis.
Failure to digest food leads to a serious problem. The excretory system helps in getting rid of undigested food and unwanted/ harmful materials from the body. That is why living things can release urine and faeces.
4. Maintaining blood pressure: Blood pressure is the pressure which blood circulates against the walls of the blood vessels. The heart notices changes in blood pressure, it sends signals to the brain, which then sends appropriate instructions back to the heart.
If blood pressure is too high, the heart should slow down; if it is too low, the heart should speed up. Increase in blood pressure leads to a disease known as hypertension while a decrease causes a disease known as hypotension.