Barbara Mason Human Growth and Development Anne Brooks Lesson 11:Ages 65 on up: Late Adulthood The Results of Aging THEORIES OF WHY WE AGE Since research into aging is not guided by any one universally accepted theory, genetic, cellular, and physiological studies have yielded several hypotheses. Genetics The most popular genetic theory, the Error Theory, assumes that aging is the result of the accumulation of random genetic damage, or from small errors in the flow of genetic information. The damage or errors would reduce or prevent proper cell function. Cellular The best known theory of aging in cellular research is called the Hayflick Effect, which is named after the American microbiologist Leonard Hayflick. He found that certain human cells could only divide a limited number of times before they die.
This may suggest that aging is programmed into cells. This could also account for the differences in the life spans of different animal species, and the differences in the life spans between the sexes within the same species. Physiological These theories focus on organ systems and their interrelationships. One area currently being investigated is the immune system. As we age the immune system gradually loses its capacity to fight off infections and other invaders. As a result, antibodies are produced that cannot tell the difference between friendly cells and enemy cells. Most experts now believe that aging represents many phenomena working together (Miller and Keane 97).
PHYSICAL CHANGES The physical changes that accompany aging are not necessarily incapacitating, even though they may be discomforting or limiting. The body has less strength and endurance as it ages. The rate of energy production in the body cells is gradually lowered so that people tire more easily and are more sensitive to weather changes. Sexual desire and ability lower although they never entirely end for either sex. The capacity to bear children ends in women with menopause, which is the time when the ovaries stop functioning, causing the menstrual cycle to stop.
Men retain their reproductive function into the late years. The use of eyeglasses may become necessary, even if they were not necessary earlier in life. Old people can hear low tones fairly well, but their ability to hear high tones decreases. The capacity of tissue and bone to repair itself is slowed, as is cellular growth and division. Bones become brittle and skin loses its thickness and elasticity, causing wrinkles.
As brain cells die some capacity for memorization and learning is lost. Breathing becomes difficult and hardening arteries circulation to worsen and blood pressure to rise. Joints lose their mobility and deteriorate from constant wear and pressure. Finally, the liver filters toxins from the blood less efficiently (Microsoft Encarta Aging). These are not all of the changes to the body that are brought about by aging, but these are the major ones. There is hope in modern medicine, though.
Through the use of new technologies and drugs some of these changes can be slowed or prevented. System Results of Aging Contributing Factors SKIN -loses thickness and elasticity (wrinkles appear) -bruises more easily as blood vessels near surface weakens -Process accelerated by smoking, -excessive exposure to sun. BRAIN/NERVOUS SYSTEM -loses some capacity for memorization and learning as cells die -becomes slower to respond to stimuli (reflexes dull) -Process accelerated by overuse of alcohol and other drugs, repeated blows to the head. SENSES -becomes less sharp with the loss of nerve cells -Process accelerated by smoking, -repeated exposure to loud noise. LUNGS -becomes less effective as elasticity decreases -Process accelerated by smoking, -poor air quality, insufficient exercise.
HEART -pumps less efficiently, making exercise more difficult -Process accelerated by overuse of alcohol and tobacco, poor eating habits. CIRCULATION -worsens and blood pressure rises, as arteries harden -Process accelerated by insufficient exercise, smoking, poor eating habits. JOINTS -lose mobility (knee, hip) and deteriorate from constant wear and pressure (disappearance of cartilage between vertebrae results in old age shrinking) -Process accelerated by injury, obesity. MUSCLES -lose bulk and strength -Process accelerated by insufficient exercise, starvation. LIVER -filters toxins from blood less efficiently -Process accelerated by alcohol abuse, viral infection.
Microsoft Encarta. Aging. MENTAL CHANGES Along with the loss of the ability of memorization and learning due to brain cells dying (Microsoft Encarta Aging); elderly people can be affected by Alzheimer’s Disease. This disease is a progressive degenerative disease of the brain, now considered to be a leading cause of dementia among the old. It affects an estimated 2.5 to 3 million people in the U.S. The incidence of this disease increases with advancing age, but there is no evidence that it is caused by the aging process. The average life expectancy of a person with Alzheimer’s is five to ten years. Alzheimer’s patients show nerve cell loss in the parts of the brain associated with cognitive functioning.
The disease also includes the formation of abnormal proteins known as neurofibillary tangles and neurotic plaques. Alzheimer’s is also identified by defects in the brain’s neurotransmitters, chemicals that transmit nerve impulses, particularly acetylcholine, which has been linked with memory function. Recent findings show that a small percentage of Alzheimer’s cases may have been inherited, and there has been a link between the disease and high amounts of aluminum in the brain (Microsoft Encarta Alzheimer’s Disease). Senile Dementia This form of intellectual impairment is observed in elderly people. Approximately 10 percent of all people over 65 years of age have clinically important intellectual impairment. Although 20 percent of these cases are treatable, such as toxic drug reactions, most cases are Alzheimer’s Disease.
Senile Dementia begins with failing attention and memory, loss of mathematical ability, irritability and loss of sense of humor, and poor orientation in space and time (Microsoft Encarta Senile Dementia). CONCLUSIONS 1. There is no one theory about why we age, but the subject is currently being researched in several areas. 2. The body goes through many changes as it ages, some of which can be slowed or prevented through the use of modern medicine. 3.
Alzheimer’s Disease is probably the most prominent mental disorder in elderly people, but research has found what it does to the brain, so a cure may be in the future. WORKS CITED Microsoft Encarta. Computer Software. Alzheimer’s Disease. Microsoft, 1993. Computer Software. Senile Dementia.
Microsoft, 1993. Miller, Benjamin F., M.D., and Claire Brackman Keane, RN, BS, M.Ed. Encyclopedia and Dictionary of Medicine and Nursing. USA: W. B. Saunders, 1972.
Riley, Matilda White. Aging. Microsoft Encarta. Computer Software. Microsoft, 1993.