Introduction
Electrolytes are a term for which one may not know exactly what is hidden behind them. They are written on some lab slips, sound terribly chemical and indeed their function and regulation are extremely complex. A simplified explanation of the medical context will be given below.
Definition
The so-called electrolytes are salts dissolved in the blood. As a comparison you can use common salt. When common salt, which is chemically called sodium chloride, is dissolved in water, the components of the salt, namely the sodium and chloride ions, separate from each other when dissolved and are surrounded by water molecules and thus dissolved.
Certain salts are also dissolved in the blood as ions, the most important of which are sodium, potassium, calcium and chloride. In addition, there is also magnesium or bicarbonate, for example, but these have other functions in the body and are less frequently determined during a blood test. As the name electrolyte implies, these ions are electrical charge carriers. Sodium, potassium, calcium and magnesium are positively charged, while chloride and bicarbonate are negatively charged. These electrolytes provide the chemical and electrical balance and are distributed throughout the body via the blood, where they are needed by each individual cell to live and function.
Function
Electrolytes have a complex function in the household of every body cell. They are particularly relevant for heart and muscle cells, in the kidney, nerve cells and sensory cells, for example in the ears or eyes. The decisive factor here is the electric charge of the ions.
In order to understand the complex mechanisms of a cell, the following principles must be considered: The predominant ion group within the body cells is potassium. Very little of it is found in the blood. Sodium, on the other hand, is mainly found in the blood and the space outside the cells and hardly ever inside the body cells.
Everything outside the cells (including the blood) is considered extracellular space, because ions can easily spread and move around in it. Somatic cells and extracellular space are different compartments. An exchange of ions between them cannot take place without openings in the form of channels in the cell walls.
There are sodium and potassium channels, which are located in the cell membrane and are closed in their initial state. Ions have the tendency to spread evenly in their compartments. If a channel between the cell and the extracellular space is opened, this driving force ensures that the ions flow to where there are fewer of them.
- The predominant ion group within the body cells is potassium. Very little of it is found in the blood. Sodium, on the other hand, is mainly found in the blood and the space outside the cells and hardly ever inside the body cells.
Everything outside the cells (including the blood) is called extracellular space, because ions can easily spread and move around in it.
- Body cells and extracellular space are different compartments. An exchange of ions between them cannot take place without openings in the form of channels in the cell walls. There are sodium and potassium channels, which are located in the cell membrane and are closed in their initial state.
- Ions strive to spread evenly in their compartments.
If a channel is opened between the cell and the extracellular space, this driving force ensures that the ions flow to where there are fewer of them.
When a signal transmitter reaches a cell, the ion channels there are opened according to the lock-and-key principle and the ions can flow into the cells. This changes the electrical charge in the cell, because the ions bring positive charges with them. This change in the electric charge in turn initiates other processes in the cell, which differ from cell to cell depending on their function.
The ions that flow in are then transported outwards again via a pump in the cell membrane to restore the original state. Another function of the ions is to bind water. The higher the salt content, the more water is attracted to it, this principle is called osmosis. This plays an important role especially in the kidneys and also explains why patients with already high blood pressure are recommended a low-salt diet. In summary, the individual electrolytes can be roughly attributed to certain organ systems for which a balance is essential.Potassium is important for the heart muscle, sodium for the kidney and blood pressure, calcium for the bones and heart, magnesium for the muscles and brain and bicarbonate for the pH, i.e. the acid-base balance of the blood.
