Sources of Water

About 70 percent of the earth's surface is covered with water. The amount of water in a human body depends on age, gender, body type, and level of physical activity. The bodies of infants up to about twelve months of age contain about 58 percent water; the bodies of children six to seven years of age are 62 percent water; teenage boys are about 59 percent water; and teenage girls are about 45 percent water. The body of an adult male is approximately 62 percent water, while an adult female is 51 percent water. Physically active individuals generally have more water in their bodies than those who are less physically active. Because they sweat more, active people need to replenish water more often, thus raising their water level. A trained male runner may have up to 71 percent water in his body, while a female gymnast may have 70 percent. Obese individuals, on the other hand, have a lower percentage of water in their bodies (about 48%). Morbidly molecule: combination of atoms that form stable particles atoms: fundamental particles of matter oxygen: O2, atmospheric gas required by all animals nutrient: dietary substance necessary for health environment: surroundings homeostasis: regulation of the proper internal state obese: above accepted standards of weight for sex, height, and age

Pakistani villagers pull water from a deep well. Overpumping of groundwater has depleted the water resources of Pakistan and many other nations around the world. [© Reuters NewMedia Inc./Corbis. Reproduced by permission.]

metabolic: related to processing of nutrients and building of necessary molecules within the cell interstitial: between the tissues protein: complex molecule composed of amino acids that performs vital functions in the cell; necessary part of the diet glycogen: storage form of sugar obese individuals are only about 36 percent water. In addition, the older one gets, the less water is retained in one's cells. As a result, old skin looks drier and wrinkles appear.

0 0

Post a comment