Water: physical and chemical properties
Thirst, headache, fatigue, weakness, constipation, dizziness, dry or flushed skin, rapid heartbeat, cramps, decrease in urine output, dark urine, low blood pressure, swollen tongue, unconsciousness and death, in the most extreme cases.
These are some of the symptoms of water deprivation (dehydration). Once the percent of water loss gets higher and higher, these symptoms are getting worse. Mild dehydration includes water losses between 1% and 2%, while severe water deprivation occurs when the body misses 10-15 % or more of its fluids. Usually, losses greater than 15% are fatal.
Why these symptoms? Why is the water so important for the human organism?
55-60% of the human body mass is water (lean muscle tissues contain 75% water; body fats -10 %; bones-22%). This simple natural compound, with the H2O chemical formula, can be found throughout the body, occupying an important percent of the volume of the cells, tissues, organs and body fluids. Even if it provides no calories or organic nutrients, its absence might lead to major dysfunctions.
Its physical and chemical properties make it indispensable for life. As a solvent, water dissolves different types of materials and then transports the essential molecules and other particles around the body. Water maintains blood circulation and moves hormones, oxygen, antibodies and nutrients through the lymphatic system and bloodstream to each cell. During the osmosis process, water diffuses through different tissues or cell membranes, making possible the movement of ions and molecules.
Water also works as a good medium for chemical reactions. Some of these reactions important for life, such as the decomposition of carbohydrates or proteins during the digestive process, take place only in the presence of water as a catalyst. The creation of some complex molecules, as hormones or nucleic acids, requires water as a main factor.
This fluid also regulates body temperature. Water has unique chemical properties that insulate it from sudden temperature changes and even help buffer temperature shifts in the surrounding medium, like air. Water is able to absorb an unusually high amount of heat before its own temperature climbs. Water also helps regulate body temperature through perspiration. Heat leaves the body as sweat, and the water evaporates off the skin.
Water is an effective lubricant in the thoracic and abdominal cavities, where the organs are located next to each other, and in joints, where the bones, ligaments and tendons have to move smooth, without frictions between different structures. For specific parts of the human body, water works as a protective layer that absorbs mechanical shocks. The spinal cord, the eyes, and even the unborn fetus benefit from this function of the water.
Water flushes toxins and waste from the body, mainly through urine and perspiration. The urine is produced by the kidney system, which is totally dependent upon water in order for it to work. They filter voluminous amounts of blood each day and in doing so maintain the body’s water balance and excrete toxins and excess fluid through the bladder.
How much water the body needs to stay healthy and to work properly?
Since the body loses water every day through breath, perspiration, urine and bowel movements, the water supply should be replenished by consuming beverages and foods containing water. Human beings can survive an average of three to five days without the intake of water, under ordinary condition; in colder or warmer temperatures, the need for water is greater and the survival is possible for a shorter period of time.
A simple rule to set the daily water requirement is that, for each 1000 kcal expended by the human body, 1 liter of water should be ingested. Since the daily calorie intake is on average of 2000 calories, nutritionists usually recommend a water consumption of 8 glasses of water daily (approximately 2 liters/day).