Importance of water in the human body

Water is a very important part of a human's bodily functions. As I travelled through the digestive system, it became apparent how many ways in which water was involved. 

Digestion & Waste Elimination

·         Water is a major component in saliva and of the digestive juices in the stomach. Water keeps the feces moist enough to pass through the alimentary canal. The kidneys also use water to dilute wastes, making them easier to pass from the body. With diseases like diabetes, the kidneys remove excess sugar from the blood and then need to dilute that sugar with extra water in order to pass it from the body.

Metabolism & Respiration

·         Metabolism of food into usable energy is a chemical process that requires a lot of water and oxygen. The body uses water to break down nutrients into their component parts. The lungs use water vapour for osmosis, the transfer of oxygen and carbon dioxide. The air sacs (alveoli) in the lungs have minute amounts of water. As air enters the lungs, the water in the alveoli break the gasses down into their component parts. It is these component parts that pass through the walls of the alveoli into the bloodstream.

Regulation of Body Temperature

·         Water is a major component of blood and sweat. Water has a high specific heat and easily absorbs large amounts of heat. The water in blood regulates body temperature by absorbing the heat from metabolic processes and transferring that heat throughout the body in the circulatory vessels. Blood also cools the body by moving to the surface of the skin, where the outside air cools the blood. The cooled blood then circulates around the body, cooling the body. This is why people with fevers appear flushed. Sweat cools the body through evaporation. The sweat sits on the surface of the skin and as it dries it releases heat. In humid areas, the concentration of water in the air prevents sweat from evaporating off the skin.

Moistening & Lubrication

·         Water moistens mucous membranes, the interior of the lungs, the pleura surrounding the lungs and the membranes surrounding the organs. This layer of moisture allows the tissues to slide over each other, preventing lesions and adhesions. Water is also a major component of synovial fluid, which cushions and lubricates the joints.