- Related Topics:
- human development
- old age
- Why do we age?
- geriatrics
- retirement
human aging
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What is human aging?
Human aging involves physiological changes that lead to a decline in biological functions and the ability to adapt to stress. These changes are typically accompanied by psychological and behavioral shifts, along with social and economic factors.
Physiologically, organ performance declines, cells are lost, and cellular enzymes become less active. The skin loses elasticity, hair grays, and wound healing slows. Bones become brittle, joints creak, and arteries lose elasticity.
From a psychosociological perspective, aging involves changes in behavior, social interactions, and activities. Theories in this area include disengagement, activity, life-course, and continuity theories, which address relationships, social activity, developmental stages, and the maintenance of personal characteristics.
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What changes happen inside the body as people age?
As people age, several physiological changes occur within the body. Organ performance, including that of the heart, kidneys, brain, and lungs, gradually declines, and the probability of death increases.
There is a loss of cells in organs, reducing the body's reserve capacities. The remaining cells may not function as well due to less active cellular enzymes. The amount of blood pumped by the heart diminishes, and fatty and connective tissues infiltrate the heart. Taste sensitivity decreases because of the loss of taste buds. Lean body mass also decreases, while body weight usually increases due to more stored fat and body water.
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How do aging organs and cells affect a person's health?
Aging affects health through various changes to cells and organs. Tissue atrophy, where tissues shrink, is typical, especially in the thymus, which is important for immunological defense. There is also a reduction of cellular tissue replaced by fatty or connective tissue in bone marrow and skin. Connective tissues become stiffer, making organs, blood vessels, and airways more rigid. Cell membranes change, reducing the efficiency of exchanging carbon dioxide and wastes for oxygen and nutrients.
Organs like the liver and kidneys lose mass and efficiency as people age. After age 40, the brain becomes smaller, especially in the frontal and occipital lobes; however, intellectual decline is usually a consequence of underlying disease conditions. Bones become lighter and more brittle due to calcium loss, and joints may creak as cartilage thins. Arteries also become fibrous and less elastic.
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What are some common health problems older adults may face?
Older adults commonly face health challenges as a result of the aging process, including declines in organ function and reserve, increasing their vulnerability to disease and disability.
Common conditions include heart and blood vessel disorders like arteriosclerosis, arthritis, and osteoporosis. There may also be degenerative changes in the brain, potentially leading to impaired mental ability. Psychological features of aging include impairments in short-term memory and cognition, resulting in slowed thinking and response.
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How does aging change a person's role or relationships in society?
Aging significantly influences an individual's societal roles and relationships. In agrarian societies, the elderly often hold respected positions due to their valuable knowledge and life experiences. However, in industrialized nations, the social status of older adults may decline due to technological advancements and changing socioeconomic conditions.
Ageism, or discrimination based on age, can negatively impact older individuals' employment, health care, housing, and mental health. As people age, they may experience institutional, interpersonal, and internalized ageism. Many older adults find that familial relationships become the primary focus. However, changing family structures in industrialized countries can lead to isolation from younger generations. Retirement can also bring stress, affecting physical, emotional, social, and spiritual well-being, and can lead to a search for new purpose. Continuity theory suggests that older adults try to maintain their values, personality, and behaviors despite health or life changes.
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What challenges and opportunities does an aging population create for communities and societies?
Aging populations present communities and societies with both significant challenges and unique opportunities. Challenges include increased demands on public health facilities to provide specialized geriatric care, rising costs for support services such as domestic help and nursing homes, and the psychological impact of isolation as family structures evolve.
However, aging populations also offer opportunities. The elderly possess valuable life experiences and knowledge that can benefit society, especially in preliterate societies where knowledge is orally transmitted. Moreover, older adults can remain active through continued social engagement and multigenerational living, contributing to their communities and fostering mutual support.
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News •
human aging, physiological changes that take place in the human body leading to senescence, the decline of biological functions and of the ability to adapt to metabolic stress. In humans the physiological developments are normally accompanied by psychological and behavioral changes, and other changes, involving social and economic factors, also occur.
Aging begins as soon as adulthood is reached and is as much a part of human life as are infancy, childhood, and adolescence. Gerontology (the study of aging) is concerned primarily with the changes that occur between the attainment of maturity and the death of the individual. The goal of research in gerontology is to identify the factors that influence these changes. Application of this knowledge can reduce the severity of some disabilities commonly associated with aging.
The biological-physiological aspects of aging include both the basic biological factors that underlie aging and the general health status. Since the probability of death increases rapidly with advancing age, it is clear that changes must occur in the individual which make him or her more and more vulnerable to disease. For example, a young adult may rapidly recover from pneumonia, whereas an elderly person may die.
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Physiologists have found that the performance of many organs such as the heart, kidneys, brain, or lungs shows a gradual decline over the life span. Part of this decline is due to a loss of cells from these organs, with resultant reduction in the reserve capacities of the individual. Furthermore, the cells remaining in the elderly individual may not perform as well as those in the young. Certain cellular enzymes may be less active, and thus more time may be required to carry out chemical reactions. Ultimately the cell may die.
Effect of aging of the body systems
Cardiovascular system
Diseases of the heart are the single largest cause of death after age 65. Thus, with increasing age, the heart becomes more vulnerable to cardiovascular disease. Even in the absence of detectable disease, the heart undergoes deleterious changes with advancing age. Structural changes include a gradual loss of muscle fibres with an infiltration of adipose tissue (fat) and connective tissue. There is a gradual accumulation of insoluble granular material (lipofuscin, or “age pigment”) in cardiac muscle fibres. These granules, composed of proteins and lipids, make their first appearance by age 20 and increase gradually, so that by age 80 they may occupy as much as 5–10 percent of the volume of a muscle fibre.
The heart also shows a gradual reduction in performance with advancing age. The amount of blood pumped by the heart diminishes by about 50 percent between ages 20 and 90 years. There are marked individual differences in the effects of age. For example, some 80-year-old individuals may have cardiac function that is as good as that of the average 40-year-old individual.
Under resting conditions, the heart rate does not change significantly with age. During each beat, however, the muscle fibres of the heart do not contract as rapidly in the old as in the young. This reduction in power, or rate of work, is due to the age-associated reduction in the activities of certain cellular enzymes that produce the energy required for muscular contraction.
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In spite of these changes, the heart, in the absence of disease, is able to meet the demands placed upon it. In response to physical exercise, it can increase its rate to double or triple the amount of blood pumped each minute, although the maximum possible output falls, and the reserve capacity of the heart diminishes with age.
Arteriosclerosis, or hardening of the arteries, increases markedly in incidence with age and is often regarded as part of aging. This is not necessarily true. Arteriosclerosis may appear even in adolescents. It is a progressive disorder and is present to some extent in practically all individuals by middle life. It is, therefore, impossible to make a clear distinction between the effects of aging and the effects of disease in blood vessels in humans. In some animal species—for example, the rat—that do not develop arteriosclerosis, age changes in the heart and blood vessels can be identified.
In general, blood vessels become less elastic with advancing age. There is a progressive thickening of the walls of larger blood vessels with an increase in connective tissue. The connective tissue itself becomes stiffer with increasing age. This occurs because of the formation of cross-links both within the molecules of collagen, a primary constituent of connective tissue, and between adjacent collagen fibres. These changes in blood vessels occur even in the absence of the deposits on the arterial wall characteristic of atherosclerosis, which interfere with blood flow through the arteries. The gradual loss of elasticity increases with resistance to the flow of blood so that blood pressure may increase. This in turn increases the work that the heart must do in order to maintain the flow of blood.
While both systolic and diastolic blood pressures (blood pressures at contraction and dilation of the heart, respectively) increase with age, the rate of systolic increase exceeds that of diastolic so that the pulse pressure widens. The increase in pressure stops in the eighth decade of life, and there may even be a slight decline in pressure in extreme old age.
On the average, obese people have higher blood pressures than those with normal body weights. Since the incidence of obesity increases with age at least up to age 55–60, this factor may contribute in part to the increase in blood pressure with age.