The Importance of Water in the Body
Water is vital for health. The average adult body is around 60% water and without consuming water we would be dead within a few days. The average person loses around 2.5 litres of water per day; 1.5 litres is lost in urine, 700ml through the skin and in the breath, 200ml in perspiration and 100ml in feces. Some water losses are replaced from cellular metabolism and food but we still need to consume around 1500ml of water per day from drinks to make up the remainder. The water in our bodies carries out a number of important functions.
Water is needed for regulation of body temperature at 37o C. When body temperature starts to rise, blood vessels near the surface of the skin dilate to release some of the heat, the reverse happens when body temperature starts to drop. Also, when body temperature rises, sweat glands secrete sweat, which is 99% water. As the sweat evaporates, heat is removed from the body.
Water provides lubrication for the joints as it is a component of synovial fluid. It is also a component of tears which lubricate the eyes and of saliva to provide lubrication to food which aids chewing, swallowing and digestion of food. It also has protective roles, washing away particles that get into the eyes, providing cushioning against shock for the eyes and the spinal cord. It is also a component of amniotic fluid which provides protection for the foetus during pregnancy.
There are chemical reactions in the body which require water. A synthesis reaction involves the joining of two molecules by the removal of a water molecule and a hydrolysis reaction involves a molecule being split into two smaller molecules with the addition of water.
Water is also a very good solvent for some substances as water molecules are polar; the two sides have a different electrical charge. Sodium chloride, (table salt), for example, easily dissolves in water as the sodium ion is positively charges and attracts to the negative pole of the water molecule and chloride is negatively charged and so attracts to the positive pole of the water molecule. Substances which dissolve in water this way are known as electrolytes.
Water is also the major component of the body's transport systems. Via the blood stream nutrients, oxygen, glucose and fats are transported to the various tissues and cells. Also, the waste products of cellular metabolism are removed, such as lactic acid and carbon dioxide. Via the urine, a number of waste products are transported out of the body, for example, urea, phosphates, sulphites, minerals, ketones from fat metabolism and nitrogenous waste from protein breakdown.
Exercise, especially in hot and humid conditions, can cause large water losses through sweating. For this reason, people who exercise need to ensure they are well hydrated before exercising and consume fluids containing electrolytes, such as sodium and potassium, during and after training to replace lost fluid. This will minimise the risk of a reduction in performance or any detriment to their health.
* MLA Style Citation:
Taranowski, Helen "The Importance of Water in the Body." The Importance of Water in the Body. 19 Jun. 2008. EzineArticles.com. 26 Aug 2008 .