HLTH201 Lecture Notes - Sun Tanning, Presbycusis, Presbyopia
Document Summary
Life expectancy how long a person is expected to live given no change in the mortality rate. The number of years a species are expected to live given optimal conditions. Number of years expected to live disease free. A limit to the number of times a cell can divide, leonard time. Their cohort have already died, natural selection, thus free of disease. Random primarily environmental factors, free radical theory, reacting with body"s cells causing chaos!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! causing cell damage, damage dna, enhance aging. Could be increase in free radicals or decrease in antioxidants. Telomere shortens to a point where a cell can no longer divide. Group with similar characteristics, centenarians, they"ve lived a long time, specific factor that allowed them to live for a period of time greater than the expected. Has not yet been proven in humans, cannot recreate in a lab environment. Difficult to maintain such a diet, quality of life decreases, can"t enjoy life.