How Does the Cell Help Maintain Homeostasis?

What is Homeostasis?

Homeostasis is derived from Greek, meaning to stand equally. The term was coined by Walter Bradford Cannon to describe a theory of physiology expounded by Claude Bernard. The theory stated that, in order for a closed system to maintain equilibrium with it's surrounding environment, the system could not really be closed. In fact the system requires many minute exchanges and dynamic adjustments to maintain the status quo. This theory has since been applied in many different situations; including ecology, economy, as well as it's intended biology.

Why is the Homeostasis of a Cell Important?

A cell must maintain equilibrium or homeostasis with it's surrounding environment in order to function at optimum capacity. As the cell is a place where chemical and electrical transactions occur, the cell must be able to excrete waste and take in new materials in equal measure. Unfortunately, the needs of the cell change from moment to moment as the rates at which these chemical processes take place differ. This means the cell requires a regulating system. Without this regulating system the cell is unable to maintain homeostasis. On a large scale this results in many diseases such as diabetes, gout, and any disease resulting from toxins present within the bloodstream. The cell is not designed to run forever and the gradual loss of homeostasis is largely to blame for the physical characteristics of aging. Extreme and sudden loss of homeostasis can also result in heart failure, as the cellular exchange of Potassium for Sodium in the surrounding interstitial fluid of the body also happens to be the same process which fuels the heart's impulse to beat.

How the Cell Maintains Homeostasis.

Homeostasis is maintained on an individual level, by the semi-permeable membrane surrounding the cell called the plasma membrane. This membrane is made of a thin layer of long chained phospho-lipids. Lipids are fats and the plasma membrane is semi-water repellent. The cell exists in an interstitial fluid medium, which is primarily water. The exchanges of the material between inside and outside the cell happen by three processes: diffusion, osmosis, and active transport. Diffusion occurs when there is a high concentration of a material within the cell and a low concentration of the chemical in the interstitial fluid. The material will flow through the plasma membrane until the levels inside and outside the cell are equal. Osmosis works when there is a low concentration of material inside the cell and a high concentration outside the cell. The material passes through the membrane until equilibrium has been reached. The process of active transport involves the expenditure of metabolic energy. Each cell indicates its condition by excreting specific chemical transmitters to the hypothalamus. The hypothalamus reads the cells condition and then sends signals back with instructions to the plasma membrane if they are required. It is by this process that the plasma membrane is capable of deliberately pulling in certain materials and compounds against the tendencies of natural equilibrium in order to meet cell's ever changing needs. These three processes, maintain homeostasis in the cell.

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