theories of aging

Download THEORIES OF AGING

Post on 05-Jan-2016

179 views

Category:

Documents

0 download

Embed Size (px)

DESCRIPTION

THEORIES OF AGING. Based on information in: Madison, H.E. (2002).“Theories of Aging”. In Lueckenotte, A.G. (ed), Gerontologic Nursing. St. Louis: Mosby. Theories of Aging: attempt to explain the phenomenon of aging as it occurs over the lifespan - PowerPoint PPT Presentation

TRANSCRIPT

  • THEORIES OF AGINGBased on information in: Madison, H.E. (2002).Theories of Aging. In Lueckenotte, A.G. (ed), Gerontologic Nursing. St. Louis: Mosby.

  • Theories of Aging:attempt to explain the phenomenon of aging as it occurs over the lifespan

    aging is viewed as a total process that begins at conceptionsenescence: a change in the behavior of an organism with age leading to a decreased power of survival and adjustment

  • Theories of Aging: TypesBiologic

    Sociologic

    Psychologic

    Moral/Spiritual

  • Biologic Theories:

    Concerned with answering basic questions regarding the physiological processes that occur in all living organisms as they chronologically age

  • Foci of Biologic TheoriesExplanations of:1) deleterious effects leading to decreasing function of the organism

    2) gradually occurring age-related changes that are progressive over time

    3) intrinsic changes that can affect all member of a species because of chronologic age

  • ALSO:all organs in any one organism do not age at the same rate

    any single organ does not necessarily age at the same rate in difference individuals of the same species

  • Biologic Theories: Divisions

    Stochastic: Explain aging as events that occur randomly and accumulate over time

    Nonstochastic: View aging as certain predetermined, timed phenomena

  • Stochastic Theories

    Error TheoryFree Radical Theory

    Cross-Linkage Theory

    Wear & Tear Theory

  • Error TheoryOriginally proposed in 1963Basis: 1)errors can occur in the transcription in any step of the protein synthesis of DNA2) error causes the reproduction of an enzyme or protein that is not an exact copy3) As transcription errors to occur, the end product would not even resemble the original cell, thereby compromising its functional ability

  • Error, contdMore recently the theory has not been supported by researchnot all aged cells contain altered or misspecified proteins

    nor is aging automatically or necessarily accelerated if misspecified proteins or enzymes are introduced into a cell

  • Free Radical TheoryFree radicals are byproducts of metabolism--can increase as a result of environmental pollutantsWhen they accumulate, they damage cell membrane, decreasing its efficiencyThe body produces antioxidants that scavenge the free radicals

  • Free Rads, contdIn animal studies, administration of antioxidants postpones the appearance of diseases such as cardiovascular disease and CA

    Free radicals are also implicated in the development of plaques associated with Alzheimers

  • Cross-Linkage TheorySome proteins in the body become cross-linked, thereby not allowing for normal metabolic activities

    Waste products accumulate

    Result: tissues do not function at optimal efficiency

  • C-L Theory, contdSome research supports a combination of exercise and dietary restrictions in helping to inhibit the cross-linkage process

  • Wear & Tear TheoryProposed first in 1882

    Cells simply wear out over time because of continued use--rather like a machine

    Would seem to be refuted by the fact that exercise in OAs actually makes them MORE functional, not less

  • Nonstochastic Theories:

    Programmed Theory

    Immunity Theory

  • Programmed (Hayflick Limit) TheoryBased on lab experiments on fetal fibroblastic cells and their reproductive capabilities in 1961

    Cells can only reproduce themselves a limited number of times.Life expectancies are seen as preprogrammed within a species-specific range

  • Immunity TheoryImmunosenescence: Age-related functional diminution of the immune system

    Lower rate of T-lymphocyte (killer cells) proliferation in response to a stimulus

    & therefore a decrease in the bodys defense against foreign pathogens

  • Immunity, contdChange include a decrease in humoral immune response, often predisposing older adults to:1)decreased resistance to a tumor cell challenge and the development of cancer2) decreased ability to initiate the immune process and mobilize defenses in aggressively attaching pathogens3) increased susceptibility to auto-immune diseases

  • EMERGING THEORIES OF AGING

    Neuroendocrine Control (Pacemaker) Theory

    Metabolic Theory/Caloric Restriction

    DNA-Related Research

  • Neuroendocrine Controlexamines the interrelated role of the neurologic and endocrine systems over the life-span of an individual. (p. 24)

    there is a decline, or even cessation, in many of the components of the neuroendocrine system over the lifespan

  • Neuro, contdResearch has shown1) the female reproductive system is controlled by the hypothalamus. What are the mechanisms that trigger changes?2) adrenal glands DHEA hormone3) melatonin (from pineal gland)--a regulator of biologic rhythms and a powerful antioxidant. Declines sharply from just after puberty

  • Metobolic Theory of Aging (Caloric Restriction)proposes that all organisms have a finite amount of metabolic lifetime and that organisms with a higher metabolic rate have a shorter lifespan. (p. 24)

    Rodent-based research has demonstrated that caloric restriction increases the lifespan and delays the onset of age-dependent diseases

  • DNA-Related ResearchMajor Developments:

    Mapping the human genome (there may be as many as 200 genes responsible for contolling aging in humans)

    Discovery of telomeres

  • SOCIOLOGIC THEORIES OF AGING

    Disengagement TheoryActivity/Developmental Task TheoryContinuity TheoryAge Stratification TheoryPerson-Environment Fit Theory

  • Changing FOCUS of Sociological considerations of aging:60s focus on losses and adaptation to them70s broader global, societal, and structural factors influencing lives of OAs80s-90s exploration of interrelationships between OAs and their physical, political, environmental & socioeconomic mileau

  • Disengagement TheoryCumming & Henry--1961Aging seen as a developmental task in and of itself, with its own norms & appropriate patterns of behaviorappropriate behavior patterns involved a mutual agreement between OAs and society on a reciprocal withdrawal.No longer supported

  • Activity Theory (Developmental Task Theory)Havighurst, Neugarten, Tobin ~1963

    Activity is viewed by this theory as necessary to maintain a persons life satisfaction and a positive self-concept. (p.27)

  • Activity, contdTheory based on assumptions:1) its better to be active than inactive

    2) it is better to be happy than unhappy

    3) an older individual is the best judge of his or her own success in achieving the first two assumptions

  • Continuity TheoryHow a person has been throughout life is how that person will continue through the remainder of life

    Old age is not a separate phase of life, but rather a continuation and thus an integral component

  • Age Stratification TheoryRiley--1985Society consists of groups of cohorts that age collectivelyThe people & Roles in these cohorts change & influence each other, as does society at largeThus, there is a high degree of interdependence between older adults & society

  • Person-Environment Fit TheoryLawton, 1982Individuals have personal competencies that assist in dealing with the environment:ego strengthlevel of motor skillsindividual biologic healthcognitive & sensory-perceptual capacities

  • P-E Fit, contdAs a person ages, there may be changes in competencies & these changes alter the ability to interrelate with the environment

    Significant implications in a society that is characterized by constantly changing technology

  • PSYCHOLOGIC THEORIES OF AGINGMaslows Hierarchy of Human Needs

    Jungs Theory of Individualism

    Eriksons Eight Stages of Life

    Pecks Expansion of Eriksons TheorySelective Optimization with Compensation

  • Maslows Hierarchy of Human NeedsMaslow--1954each individual has an innate internal hierarchy of needs that motivates all human behaviors. (p. 29

    depicted as a pyramid; the ideal is to achieve self-actualization, having met all the lower level needs successful

  • Maslows fully developed, self-actualized person displays high levels of all of the following characteristics: perception of reality; acceptance of self, others, and nature; spontaneity; problem-solving ability; self-direction; detachment and the desire for primacy; freshness of peak experiences; identification with other human beings;.

  • satisfying and changing relationships with other people; a democratic character structure; creativity; and a sense of values.

    Only about 1% of us are truly ideal self-actualized persons

  • Jungs Theory of IndividualismCarl Jung--1960origins are FreudianSelf-realization is the goal of personality developmentas individual ages, each is capable of transforming into a more spiritual being

  • Eriksons Eight Stages of Life1993Stages throughout the life course. Each represents a crisis to be resolved.For OAs:40 to 65 (middle adulthood): generativity versus self-absorption or stagnation65 to death (older adulthood): ego integrity versus despair

  • Erikson, contdSelf-absorbed adults will be preoccupied with their personal well-being and material gains. Preoccupation with self leads to stagnation of lifeUnsuccessful resolution of the last crisis may result in a sense of despair in which individuals view life as a series of misfortunes, disappointments, and failures. (p.30)

  • Pecks Expansion of Eriksons TheoryEriksons last two stages are expanded to 7The final three of the developmental tas

Recommended

View more >