Human body contains of 60% of water. If we squeezed it out like a lemon, we would get about 50 l of water. This is not ordinary water, because it contains other substances. Blood vessels have about 4 l of water. Our heart keeps this water with its constant circulation in our body. This blood water, in fact, washes every cell of our body. Water conducts heat through our body. If we do not drink water, however, we take it daily with some food (fruit, vegetables, bread and meat contain 30%-90% of water). We all add up to 2 l of water every day, which goes from the intestines to the blood.
During the day, 10 l of water circulates between various organs in our body. As we chew food, we bring in a small amount of saliva from the salivary glands, which we swallow with food. The water in the salivary glands is compensated by water from the blood vessels. The amount of water in the blood always remains the same. No matter how much water we drink during the day, the amount of water in the blood, is the same.
The excess water is distributed equally by other organs, i.e. It goes into the intestines, liver, muscles and kidneys. If we do not drink any liquid for three weeks, we are condemned to death. Our body needs liquid supplies everyday, although it contains 60% of water. An average adult loses 700 g of water during the day by sweating and eliminates 1.3 l through waste materials. By digesting food, the body gets 350 g of water per day. This process of losing and taking fluid is not enough for our organism. That’s why we feel thirst, which reminds us, that the body needs some fluid.
We do not feel thirsty because our mouth or throat is dry, but for other reasons: hard working day, nervousness, slow retreat of the salivary glands. Their normal functioning can boost lemon juice, but it does not affect the thirst. The operation of the salivary glands can be normal, the bladder, the stomach and the bloodstream can be full of water, and we still feel thirsty. We can drink several glasses of water, among which we eat peanuts, we feel thirsty still. The stomach causes a change in the amount of salt in our body. Blood content of a quantity of salt and water. If this relationship is disturbed, we feel thirsty. The center of thirst (which is located in our brain) reacts to certain amounts of salt and water in our body. When these quantities are changed, the brain reacts and then we feel thirst.