our way (Ricklefs and Finch, 1995, 34). In addition to the decrease in unused T-cells, antibodies used against the body=s own proteins are occasionally made. This faulty process is common in autoimmune diseases like multiple sclerosis (Ricklefs and Finch, 1995, 36). Whereas this theory of how we age is a very practical one, it almost assumes that older people die as a result of infections, no matter how mild, because of a weakened immune systems. This is often, not so. Wear and Tear Just as machinery and other equipment gets worn down through use, so too do our organs and cells. It is almost inevitable that once our first cells have developed and our organs begin functioning, they also begin a very gradual deterioration through use. In fact, heavy use of our organs and bodies can accelerate this deterioration we call aging (Ricklefs and Finch, 1995, 33). In typists, for example, carpal tunnel syndrome and other degenerative problems come about faster and more commonly than in those who do not exhibit such specialized use of their fingers. On the other hand, problems can also arise from lack of use. Muscle atrophy, which is noticed in the elderly is the result of a lack of muscle use (Ricklefs and Finch, 1995, 33). So assuming that moderate use of our bodies is healthy and will not promote any degenerative problems seems safe. Still, even regular, moderate use of one=s body, however long it can prevent certain problems, does not hold the body=s performance at the same level for very long. As aging continues, a loss of elasticity from the connective tissues in various parts of the body is experienced, and muscle performance, among other things, is reduced (Ricklefs and Finch, 1995, 33). In 1900, the life expectancy in the U.S. was 47 years. It may be thought that this was the length of time the human body could withstand *wear and tear= before it Abroke down.@ Today, the life expectancy in the U.S. is about 76 years because of modern tec...
