Concept of Homeostasis

Concept of Homeostasis 

The Protection of internal environment from the harm of fluctuation in External environment is called homeostasis.The homeostasis reduces the internal fluctuations in the body as compared to many external fluctuations. It reduces these fluctuations with the help of different control systems.

Each organism inherits a specific set up of internal environment at different levels of organizations. This internal environment is most suitable for the external envtronment. The external environment and its component fluctuate continuously. But the organisms resist  these changes. The organisms have internal adjustment. So that its internal fluctuation remains within a narrow range. Thus homeostasis protects form fluctuations in the external environment.

Control at organism level: 

The fluctuation in the external environment affects the three components of the internal environment. These are water,solute and temperature. There are

Osmoregulation: "To maintain the water and salt balance in the body or control of osmosis is called osmoregulation.” it is a mechanism of regulation of solute between the internal and external environment.

Excretion: "The mechanism of elimination of nitrogenous wastes is called excretion.” The adaptation of this mechanism also depends on the availability of water.

Thermoregulation: The maintenance of internal temperature within a tolerable range is called thermoregulation.

Control at cell level :

There is also a control system at cell level. This control system keeps the fluctuations in intracellular and extracellular environment in narrow range. The intracellular environment is present within the cell membrane. While extracellular environment is interstitial fluid. This system keeps the water, solute, metabolites, hormone etc in a required range in the cells.

Objects of homeostasis: . 

The homeostasis does not mean to keep the internal environment fixed. But to maintain the changes within a specific range . This range is necessary for the normal functioning of the body. For example, the availability of water may fluctuate for the organisms greatly in the external environment. it may be from abundant supply to almost dry condition. However, the quality of water in the body (internal environment) may vary in response to the abundant or dry condition. But this variation is within a narrow range. The control system does not allow excessive water to enter into the body when there is abundant supply of water. it also does not allow it to dehydrate in dry condition. Furthermore, the adaptation to the lower level range in dry condition and higher level range in abundant supply of water is good for the organism. Thus organism feels normal even in drastic external

Nature of controlling system: 

The control system is used for different homeostatic regulations.

1. Receptor
2. Control centre
3. Affecter 

There is a sensor in physical control system like temperature control system in refrigerators. This sensor is in the form of thermometer. lt monitors the change of temperature from the set point. It sends signals to control centre. The control centre takes necessary action. If there is drop or rise in temperature as compared to the set point, the control centre switches on the heater or cooler units.

Similarly, the endothermic (warm blooded) animals have a set point. The receptors detect the temperature change like sensor. These receptors send signals to control centre which the cools or warms the organism.The detection of change, sending signals to control centre and response of effectors is a feed back mechanism. in this process. the effectors show inverse to the change in the external environment. Thus if warmth temperature is sensed in the external temperature the effectors the effectors show response in thr form of cooling body.it is called negative feedback mechanism.