What are the functions of water (at least 1) urgent! !

the important role of water in human body: water is the foundation of life. It is recognized by various schools that water participates in the physiological function of human body, and water is the most abundant component in human body, and body fluid accounts for about 7% of human body weight, which is necessary to maintain normal physiological function. As long as 15% of water is lost, life is in danger. Nothing plays a more important role than water in the diet we ingest through the mouth. According to the research of physiologists, people can live for about four weeks or even two and a half months without eating, but if they don't get dripping water, they can only stand it for three days at room temperature at most. If it is hot summer, I'm afraid they can't stand it for even one and a half days. In the plight of isolation and helplessness, life will last for a long time as long as there is water; If you can't eat when you are sick, the first thing you need to supplement is water. According to the content of water in the body, the brain and spinal cord account for the most, accounting for about 99%; Followed by lymph glands, accounting for about 94%; The water in the blood accounts for about 83%; Water in muscle accounts for about 77%; Although bones are hard, they also contain 2% water. The above refers to the body of adults, and babies account for about 8% of the whole body on average. Dry mouth is a signal that the human body needs water, and we often drink water at this time. In fact, it is our body that is dehydrated. This bad habit of drinking water only after dry mouth leads to frequent dehydration of our bodies, which is harmful to our health. To sum up, the physiological functions of water in the human body mainly include: 1. Help digestion: The food we eat every day must be chewed by teeth and wetted by saliva, and then it can be completely digested and absorbed through the esophagus and stomach. These processes all need water to help; Without water, the digestive function cannot be completed. 2. Waste excretion: The residue and waste left after food is digested and absorbed must be excreted through sweat, breathing and defecation. Although there are different excretion methods, water is needed to help it go smoothly. 3. Lubrication of joints: If there is no lubricating fluid in the joints of human body, friction between bones will make the joints inflexible, and water is the source of joint lubricating fluid. 4. Balance body temperature: The relationship between water and body temperature is very close. When it is cold, blood vessels contract, the amount of blood flowing to the skin decreases, and water is not easily discharged, so that the body temperature can be balanced. In summer, blood vessels expand and the amount of blood flowing to the skin increases. At this time, water also flows to the skin through blood, and then is discharged from the skin surface by sweat glands. Because sweat evaporates, the heat on the skin surface is reduced, and the body temperature can be kept in balance. 5. Maintaining cells: The human body is composed of countless cells, most of which are water, and only water can maintain the metabolism of the skin. 6. Lymph and blood: transporting nutrients, excreting wastes and circulating work are all driven by water, and the activities of all parts of the human body and the metabolism of every organ also need water to maintain. Therefore, the best way is to pay attention to replenish water in time to avoid dehydration. Otherwise, the body is constantly and continuously short of water, so the metabolism will not go smoothly and the body's function will gradually decline. According to the needs of the human body, medical experts believe that it is appropriate for people to take an average of 2.5 liters a day. The water needed by the human body is first obtained from drinking water and then from food. When enough water is ingested, the circulation of blood and lymph will be in good condition. In this way, we can ensure the supply of nutrients needed by the body, dissolve waste and eliminate toxins, thus improving the function of internal organs and making the skin moist and smooth. This is necessary for the health of young people and children, especially for the elderly.