Water is of utmost importance to all living things. Plants, animals, and human beings need water for their basic survival.
Your body is about two-thirds water. On an average, a person takes in about 60,600 litres of water during his or her lifetime.
But the water in your body does not exist in its ordinary state, numerous substances are discovered in it. Blood comprises about a gallon of water which is continuously circulated in the body. This water conducts heat to every part of the body and oxygen to every cell.
The human body needs certain nutrients or food substances to survive. Watery solutions help dissolve these nutrients and carry them to all parts of the body. Chemical reactions within the body turn nutrients into energy, or into the materials it needs to grow or to repair itself.
These chemical reactions are possible only in a water solution. Finally, the body requires water to carry away the waste products after food substances have been digested.
Every human being must keep his water supply near normal, or he will die. A person can live without water for only about a week.
The human brain is more watery than blood — it is four-fifths water.
Why do we get thirsty?
Water is one of our most basic needs. Fifty to sixty per cent of our weight is water. A loss of 20 per cent of the total body water can lead to death. This is why the body needs to replenish its liquid supply.
Thirst is a sensation caused by the body’s need for water. The organs and tissues in the body need certain amounts of water and salts to function properly. Too much or too little water or salt can damage or destroy cells. Therefore, we need to regulate and control our water intake.
Thirst is often described as a dry feeling in the throat. Lack of sufficient saliva can produce this kind of thirst, even when the internal environment of the body does not need more water.
Similarly, the thirst sensation created by the internal environment’s needs will disappear briefly if water is drunk and wets the throat. But unless the water reaches the internal environment, thirst will recur after a short time.
Although a person feels warmer drinking alcohol, the body temperature actually falls as a result of drinking it.