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3. theories of aging

  1. 1. THEORIES OF AGING
  2. 2. OBJECTIVES At the end of this session students will be able to: define aging explain the theories of aging
  3. 3. INTRODUCTION Aging: Aging is the process of becoming older. Ageing represents the accumulation of changes in a human being over time, encompassing physical, psychological, and social changes. Reaction time, for example, may slow with age, while knowledge of world events and wisdom may expand.
  4. 4. THEORIES OF AGING Biological theories Psychological theories Environmental theories Developmental theories
  5. 5. BIOLOGICAL THEORIES Cellular theory: Cells has been subject of much scientific inquiry in exploring aging phenomena.
  6. 6. CONTD.. Cells has three distinct components: •Cells that can reproduce •Cells that cannot produce •Intercellular substance/materials
  7. 7. CONTD… Programmed theory: According to this theory aging and death are natural and necessary part of genetics. The human are programmed to age and die.
  8. 8. CONTD… Error theory: Aging is a result of internal and external assaults that damage cells or organs so they can no longer function properly. Mistranscription and mistranslation of certain genes products results in self amplifying error producing derangement.
  9. 9. CONTD… Somatic theory: The theory states that aging is an imbalance between DNA’s ability to repair itself and accumulating DNA damage. When the damage exceeds the repair, the cell mutation, this lead to senescence.
  10. 10. CONTD… Wear and tear theory: Years of damage to cells, tissue and organs eventually wears them out. Wear and tear can be viewed as a result of aging and not the cause of it.
  11. 11. CONTD… Auto immune theory: Postulates that with age, immune system produces auto anti-bodies that causes cell death or changes that foster the aging process.
  12. 12. CONTD… Free radical theory: During aging, damage produced by free radicals cause cells and organs to stop functioning. Molecules that are damaged by free radicals are proteins and DNA.
  13. 13. CONTD… This theory purpose that little by little small damage accumulates and contributes to detoriation of tissue and organs.
  14. 14. CONTD… Cross linkage theory: Also known as collagen theory. With age, protein, DNA and other structured molecules develop inappropriate cross links to one another which decreases the elasticity of protein and other molecules. Damage and unneeded protein stick around and can cause problem.
  15. 15. PSYCHOLOGICAL THEORIES Activity theory (Havighrust 1963): The activity theory basically says: the more you do, the better you will age. The activity theory occurs when individuals engage in a full day of activities and maintain a level of productivity to age successfully.
  16. 16. CONTD… Disengagement theory(Cumming & Henry 1961): This theory viewed aging as a process through which society and the individual gradually withdraw or disengage from each other.
  17. 17. CONTD… Continuity theory(Negatron 1964): The continuity theory states that individual who age successfully continue habits, preferences, lifestyle and relationship through midlife and later.
  18. 18. CONTD… Social exchange theory: Postulates that social interaction between individuals and groups continues as long as everyone profits from the interaction. The decrease in the social interaction of the aged is the result of exchange relationship that gradually erodes the power of the aged.
  19. 19. ENVIRONMENTAL THEORIES Radiation theory: Excessive exposure to the suns radiation puts the skin at risk during the somatic mutation process.
  20. 20. CONTD… Stress theory: According to Perlman(1954) ’Human aging is a disease syndrome arising from a struggle between environmental stress and biological resistance and relative adaption to the effects of stressor agents. These stressors agents might include air, pollutant, chemical, psychological and sociological events.’
  21. 21. DEVELOPMENTAL THEORY Erikson theorized that person’s life consists of eight stages. Each stage represents a crucial turning point in life stretching from birth to death, with its own developmental conflicts to be resolved.

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