old age

old age

[′ōld ′āj]

(geology)

The last stage of the erosion cycle in the development of the topography of a region in which erosion has reduced the surface almost to base level and the land forms are marked by simplicity of form and subdued relief. Also known as topographic old age.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

old age

the last part of the individual LIFE COURSE, associated with declining faculties, low social worth and detachment from previous social commitments. It is a social construct rather than a biological stage, since its onset and significance vary historically and culturally. See also AGEING, GERONTOLOGY.

Collins Dictionary of Sociology, 3rd ed. © HarperCollins Publishers 2000

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Old Age

 

the period of life that inevitably sets in after middle age and is characterized by significant metabolic, structural, and functional changes in organs and systems that limit the adaptability of the body. Old age is a result of the dynamic process of aging. According to one system of age classification, 75–90 years of age is considered old age, and over 90, advanced old age.

An individual’s physical appearance, work capacity, and mental abilities change with old age, as does the course of many diseases. The skin becomes thinner and less elastic, and wrinkles and pigment spots appear. The hair turns gray and falls out. Visual acuity decreases, and lenticular opacity develops, often resulting in the formation of cataracts. An individual may grow shorter, and curvature of the spine is common. Joint mobility is limited, and bones become fragile and lose calcium. Mental performance declines, and a person becomes more easily fatigued, less able to recall recent events, and subject to sleep disturbances.

Because of their adaptive mechanisms, some old people can maintain a high level of intellectual activity for a long time and remain alert and creative. With old age, organs and tissues are less influenced by neural factors but are more sensitive to humoral influences. Age-related changes in the vascular wall and in protein and lipid metabolism contribute to the progression of atherosclerosis. Changes in digestion may cause vitamin deficiency. The rate of aging and extent of changes in organs and tissues vary with each individual. (For changes that occur with aging on the cellular level and in functional systems see.)

V. V. FROLKIS

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.