Cohen, Gene D. Formerly, National Institute on Aging, National Institutes of Health, Bethesda, Maryland.
Last reviewed:June 2019
Show previous versions
- Aging versus illness
- Theories of aging
- Life extension
- Links to Primary Literature
- Additional Readings
An age-contingent reduction in physiological function and activity, with a concomitant increase in mortality rate and a diminution in reproductive rate. Aging is the process of becoming older, which is influenced by genetic and environmental factors. However, definitions of aging differ between biologists and behavioral scientists. Biologists regard aging as reflecting the sum of multiple and typical biological decrements occurring after sexual maturation; in contrast, behavioral scientists view it as reflecting regular and expected changes occurring in genetically representative organisms advancing through the life cycle under normal environmental conditions. It is difficult to define normal aging because many changes observed in older adults and perceived as concomitants of normal aging are effects of disease in later life. The behavioral science view allows for incremental as well as decremental changes with aging. Senescence is not always equated with aging; it is viewed as the increasing vulnerability or decreasing capacity of an organism to maintain homeostasis as it progresses through its life span, leading to death (Fig. 1). Gerontology refers to the study of aging. Geriatrics refers to the clinical science that is concerned with health and illness in the elderly. See also: Cell (biology); Cell senescence; Death; Genetic influences on aging; Genetics; Human genetics
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information