Theories of Aging Flashcards
___________ is the outcome of diverse and complex changes in normal biological functions, from the accumulation of DNA damage to dysfunction of proteins and altered communication both within cells and among distant tissues in the body
Aging
A measure of an individual’s age based on the calendar date on which he or she was born
Chronological Age
It is calculated on most psychological tests
Chronological Age
Classification of Aging
- Objectively
- Subjectively
- Functionally
Aging is a universal process that begins at birth and is specified by the chronological age criterion
Objectively
Aging is marked by changes in behavior and self-perception and reaction to biologic changes
Subjectively
Aging refers to the capabilities of the individual to function in society
Functionally
Refers to the health status assess functioning at the level of the whole older person, describing how that person functions in daily life
Functionally
Theories of Aging
- Biologic Theories
- Psychosocial Theories
- Psychologic Theories
2 Main Categories of Biologic Theories
- Error Theories
- Programmed Theories
Examples of theories under Error Theories
- Wear and Tear Theory
- Cross-Link Theory
- Free Radical Theory
- Somatic DNA Damage Theory
Examples of theories under Programmed Theories
- Programmed Theory
- Endocrine Theory
- Immunological Theory
Based on the idea that errors can occur in the transcription of the synthesis of the DNA
Error Theory (Orgel, 1963)
Begins to produce cells that are not correct
Error Theory (Orgel, 1963)
This deterioration results in aging and eventually over a lifetime, death
Error Theory (Orgel, 1963)
This is evidenced by localized brain cell death following a stroke or deprivation of oxygen
Deprivation
Stresses leave residual effects that are accumulated over one’s life, depleting the physiologic body
Failure of the body mechanism to adapt to stressors can be linked to aging
Stress and Adaptation
Proposed that cells wear out over time because of the continued use
Wear and Tear Theory (Weisman, 1882)
Reflects that organs and tissues have pre-programmed amounts of available energy
Wear and Tear Theory (Weisman, 1882)
An accumulation of cross-linked proteins resulting from the binding of glucose to protein causes various problems
Cross-Link Theory
Once the binding occurs, the protein cannot perform normally and may result in visual problems like cataract or wrinkling and skin aging
Cross-Link Theory
Damage cells and tissues, slowing down bodily processes and thus result in aging
Cross-Link Theory
Can increase as a result of environmental pollutants
Free Radical Theory
May react with the cell membrane, damaging it and making it more permeable
Free Radical Theory
Can cause mutation in the DNA/RNA
Free Radical Theory
This theory holds that mutations are those inheritable changes that occur in the cellular DNA
Somatic Mutation Theory
If there is extensive damage to DNA and it is not repaired, then there will probably be an alteration in a genetic sequence
Somatic Mutation Theory
Describes how exposure to low doses of radiation accelerates the aging process
Somatic Mutation Theory
Assumes that these exposures shorten the life span by mutating the cells
Somatic Mutation Theory
Showed that functional changes do occur within the cells
Programmed Theories
Life expectancy was generally seen as pre-programmed within species - specific range
Programmed Theories
Each individual has a genetic “program” specifying an unknown but predetermined numbers of cell divisions
Programmed Theories
Aging is the result of the sequential switching on and off of certain genes
Programmed Longevity
It presumes that there is a biological clock controlled by a person’s genes
Programmed Longevity
Therefore, one’s longevity and senescence follow a pattern determined by the genetic structure and when age-associated functional deficits are manifested
Programmed Longevity
Biological clocks act through hormones to control the pace of aging
Endocrine Theory
It focuses on the complicated chemical interactions set off by the hypothalamus of the brain
Endocrine Theory
It is the idea that regular changes in hormones control aging
Endocrine Theory
Changes occur in the immune system, specifically in the T-lymphocytes as a result of aging
Immunity Theory
These changes leave the individual more vulnerable to diseases
Immunity Theory
The term “immunosenescence” has been given to age related decrease in immune function
Immunity Theory
This theory states that the immune system is programmed to decline over time, leaving people more susceptible to disease
Immunity Theory
It proposes that the increase in autoimmune disease and allergies seen with aging is caused by changes in the immune system
Immunity Theory
