Dehydration

 

The number of human body fluids is always set correctly. Approximately 60% of our body is water:
2 / 3 are in the cell, 1 / 3 is outside the cell (extracellular)
Of extracellular water 1 / 3 are in the bloodstream and 2 / 3 (= interstitial water) outside the blood stream.
At a weight of 60 kg:
total body fluids: 36 liters
in the cell: 24 liters
outside the cell: 12 liters
Interstitial water: 8 liters
• How does the body maintain the proper amount of water in the cell?
• How does the body maintain the proper amount of water in the room interstial?
• How does the body maintain the proper amount of water in the bloodstream?

 
Latter mechanism has been discussed. (colloid osmotic pressure, edema). In each of these mechanisms there is a difference. For the treatment of patients is very important to understand these differences.

1. The amount of water in the cell

Unlike the endothelial cells of capillaries, the walls of most body cells are free to pass water. Every hour a large number of water molecules will enter the cell but the water with the same amount will come out well from the cells at the same time. If the incoming water is too much, the cells will swell and burst. If the water is too much out, the cell will dry and can not function. Water that enters the cell will cause cell swelling, and even rupture. But the osmotic pressure of interstitial fluid maintained exactly equal to the value of part in cells, but the most important substances potassium but not sodium.

 
2. The amount of water in space interstiasial

How does the concentration of sodium, or osmotic pressure of interstitial fluid maintained at appropriate levels?. Before these questions can be answered, be helpful to see first what happens when the extra cellular sodium is too low and if too high.

If the levels of sodium and osmotic pressure extracellular too low, the water will leave the interstitial space and moved into a cell that has a high osmotic pressure. Cell will swell. This will cause muscle spasms in the great and the central nervous system of the brain swelling in the space bounded by bone. The pressure increased in brain tissue, which is marked by a great headache, nausea, vomiting and loss of consciousness. At the same time, because the fluid out of blood proteins and erythrocytes whereas stay in the blood vessels, the concentration of hemoglobin and protein in the blood flow will increase, so does the viscosity. Circulation of the blood which was concentrated into very slowly.

 
3. The amount of water in the bloodstream

If there is pure water drought water loss without loss of sodium, thirst will be very great, the patient may show symptoms of hallucinations, aggressive behavior is self destructive. But sometimes people are too weak to show aggressive behavior.

Pure water losses can occur when a high fever due to evaporation of water from the lungs, but the most typical examples of dehydration due to loss of pure water is diabetes insipidus.