Chapter 17

1. Chapter 17 Physical and Cognitive Development in Late Adulthood

2. Ageism-prejudice or discrimination based on age • Longer life spans due to healthier life styles, improved medicine, safer food and water, economic growth Primary aging- gradual inevitable process of bodily deterioration that begins in early life and continues. Secondary aging- results from disease, abuse, disuse- factors within control of the individual Functional age- how well a person functions in a physical and environment compared to chronological age

3. Gerontology- study of the aged and aging process Longevity & Life Life expectancy- age to which a person born at a certain time and place is statistically likely to live, given current age and health status; It is the average of longevity (actual length of life Life span- entire life process

4. Trends Women typically outlive men Senescene- period of obvious marked declines in body functioning associated with aging Genetic programming theories hold that body’s age according to a normal developmental timetable that is genetic Programmed senescene- specific genes switching off Biological clock- acts through genes that control hormonal changes or cause problems in the immune system

5. Telomeres- protective tips of chromosomes, shorten each time the cell divides Chronic disorders tend to occur in those with shorter telomeres and lower levels of telomerase (enzyme that enables sex chromosomes to repair their telomeres, typically change in older women Evolutionary theory of aging- reproductive fitness is the primary aim of natural selection and no reproductive purpose is served by putting genetic resources into life beyond reproductive age.

6. Variable-rate theories- (error theories), view ageing as a result of random processes that vary from person to person; aging involves damage due to chance errors in, or environmental assaults on, biological systems. Some theories focus on internal processes such as metabolism (process by which the body turns food and oxygen into energy) Wear-and-tear theory-holds that the body ages as a result of accumulated damage to the system at the molecular level. As people age, they are less able to repair or replace damaged parts.

7. Free-radical theories- focuses on harmful effects of free radicals- highly unstable oxygen atoms or molecules formed during metabolism, which react to damaged cell membranes, cell proteins, fats, carbohydrates, and DNA. Such damage is related to arthritis, muscular dystrophy, cataracts, cancer, late-onset diabetes, and neurological disorders such as Parkinson’s. Rate-of-living theory holds that the body can do just so much work; the faster it works, the more energy it uses, the faster it wears out. Speed of metabolism (energy use) determines length of life.

8. Autoimmune theory suggests that an ageing immune system can become confused and release antibodies that attack the body’s own cells. This malfunction is called autoimmunity, thought to be responsible for some aging-related diseases and disorders. This is normally genetically regulated/programmed. When mechanisms for destruction of unneeded cells malfunction, a breakdown in cell clean-out can lead to stroke damage, Alzheimer’s, cancer, or autoimmune disease; also can cause the death of needed cells.

9. Current theory incorporating both evolutionary and variable-rate theories (Hayflick) is that natural selection has resulted in energy resources sufficient only to maintain the body until reproduction. After reproduction, insufficient energy lest to continue to maintain the molecular integrity of body cells and systems, deteriorating randomly beyond the body’s capacity to repair them, increasing vulnerability to disease and death. Survival curves- percentages of people who live to various ages

10. Hayflick limit- human cells divide in the lab only 50 times. Limit therefore is 110 years. One rate-of-living theory views that the speed of metabolism (energy used), is the crucial determinate of aging, is dietary restriction. Physical Changes • Skins becomes paler, less elastic, wrinkles, varicose veins, fat and muscle shrink. • Become shorter as spinal disks atrophy

11. Organic & Systemic Changes • Aging and chronic stress can depress the immune system, making more susceptible to infections and less likely to ward them off. • Digestive tract remains relatively efficient. • Heart- becomes slower and more irregular • Deposits of fat accumulate around the heart- may interfere with functioning • Reserve capacity- (organ reserve), a backup capacity that helps the body systems function in times of stress, decreases; therefore more susceptible to effects of stress

12. The Aging Brain • Modest changes in the healthy brain. • Loss of neurons (nerve cells) in the cerebral cortex (handles most cognitive tasks) • Shrinkage in neural size due to loss of connective tissue (axons, dendrites, synapses) • Frontal cortex is first (memory and high-level cognitive functioning) • Loss of brain matter may come slowly in the central nervous system. • Lesions in the white matter of axons (usually due to hypertension) can reduce performance.

13. Cerebral cortex shrinkage faster in men. Early for women who are obese. Education (related factors, high income, less disability) may increase brain’s reserve/capacity to tolerate potentially injurious effects of aging; aerobic exercise can slow brain tissue loss; diet heavy in fruits and vegetables can retard or reverse age-related declines in brain functioning. Older brains can grow new nerve cells, once thought impossible. Especially in the hippocampus (learning and memory)

14. Sensory & Psychomotor Functioning • Differences with age. • Better aids to help overcome disabling diseases and disorders (Table 17-2; page 641) Vision & Hearing • Difficulty with depth and color perception (reading, activities, etc) • More sensitive to glare, trouble locating signs, driving becomes dangerous • Some times glasses can help

15. Cataracts-age-related macular degeneration, glaucoma, diabetic retinopathy Age-related degeneration-center of retina gradually loses ability to sharply distinguish fine details, is leading cause of impairment Glaucoma-irreversible damage to optic nerve caused by increased pressure in the eye, can result in blindness

16. Strength, endurance, balance, reaction time • Lose about 10-20% of strength by age 70 and increases after that • Walking endurance declines, flexibility for women declines, muscle strength and power may decrease.

17. Plasticity- Some losses are partially reversible (weight & power training, resistance training, spontaneous physical activity; low-impact, moderately-intense aerobic dance and exercise training can peak oxygen uptake, leg muscle strength, and vigor. Why more susceptible to falls- reduced sensitivity to receptor cells that give brain information on body’s position in space (spatial ability). Slower reflexes and impaired depth perception also factors.

18. Sleep Tend to sleep less and dream less, les deep sleep Sexual functioning Most remains consistent in sexual activity over the years. Men: longer to develop erection and to ejaculate, may need more manual stimulation, longer refractory periods. Erectile dysfunction may increase. Women: breasts engorgement and other sexual arousal signs less intense; vagina may become less flexible and need lubrication.

19. Physical & Mental Health Many remaining healthier today. Chronic conditions & disabilities • 80% have chronic conditions, 50% have two. • About 50% of those over 85, frail, vulnerable to stress, disease, disability, death

20. Common chronic conditions • Heart disease, cancer, stroke, chronic lower respiratory disease • 60% all death- stroke, heart disease, cancer • hypertension (50%) and diabetes (16%) increasing • hypertension related to cognitive declines in attention, learning, memory, executive functions, psychomotor abilities; visual, perceptual, and spatial skills • women more likely to have: hypertension, asthma, chronic bronchitis, arthritic symptoms • men more likely to have: heart disease, cancer, diabetes, emphysema

21. Common chronic conditions • activities of daily living (ADLs) 10% have difficulty carrying out • physical activity- strengthens the heart and lungs and decreases stress • inactivity- contributes to heart disease, diabetes, colon cancer, high blood pressure, obesity- which affects circulatory system, kidneys, sugar metabolism- contributes to degenerative disorders and shortens life

22. Common chronic conditions • nutrition- 81% report bad diets • plays significant role in chronic illnesses • loss of teeth- due to infrequent dental care

23. Mental & Behavioral Problems Less frequent Depression- 11% men; 18% women Heredity accounts for 50% Dementia- physiologically caused cognitive and behavioral decline sufficient to interfere with daily activities Education and large head size seem to be protective against depression

24. Alzheimer’s disease- most common and feared terminal illnesses • Memory impairment, deterioration of language, deficits in visual and spatial processing • Personality changes- rigid, apathy, egocentricity, impaired emotional control; depression, anxiety, poor judgment and problem solving, anxiety, delusions and delirium later.

25. Alzheimer’s disease- • Accumulation of protein called beta amyloid peptide • Contains excessive amounts of neurofubrillary tangles (twisted masses of dead neurons) and large waxy clumps of amyloid plaque (nonfunctioning tissue formed by beta amyloid in spaces between neurons). These become dense, spread, and destroy surrounding neurons.

26. Alzheimer’s disease- • Cognitive reserve- may enable deteriorating brain to continue to function under stress. Diet, exercise, lifestyle factors play a role in prevention. Vitamin E, n-e fatty acids, unhydrogenated unsaturated fats, oil-based dressings, nuts, seeds, fish, mayonnaise, eggs. Opposite foods encourage it. Possibly sleep apnea and head injury early in life may also cause it.

27. Cognitive Development Intelligence: abilities such as speed of mental processes and abstract reasoning may decline, others tend to improve. Fluid intelligence- ability to solve problems that require little or no previous knowledge Declines earlier in life though not necessarily to impact in later life. May not decline as much as once thought. Crystallize intelligence- ability to remember and use information acquired over lifetime Improves until late in life, even in later life  

28. Memory Short-term memory • Sensory memory- retains efficiency throughout life • Working memory- gradually shrinks after age 45 • Tasks that require rehearsal or repetition decline little • Tasks that require reorganization or elaboration shower greater decline 

29. Memory Long-term memory Episodic memory- (recently stored memory- recent events) deteriorates with age Semantic memory- (stored knowledge of historical facts, customs, locations, meanings of words) not dependent on remembering when/where something was learned, shows little decline with age

30. Memory Long-term memory Procedural memory- (knowledge of how to do something- motor skills, habits, without conscious effort) relatively unaffected by age though slower responses. Priming- memory that is unconscious, ability to problem solve, answer a question, do a task, identify a picture or recall familiar word- declines little.

31. Speech and memory Better than young people in remembering a word. But more difficulty coming up with the word if given the definition. Why memory problems • Less efficient in encoding new information • Some storage memory may deteriorate to point where retrieval becomes difficult or impossible • Traces of decayed memories are likely to remain, possible to reconstruct them or at least to relearn the material • Takes longer to recall.

32. Neurological changes Hippocampus-critical to ability to store new information in episodic memory, loses about 20% of nerve cells with advancing age Unconscious learning- apparently independent of the hippocampus, is less affected; recall of prior learning, may increase. Frontal lobes- involved in encoding and retrieval of episodic memories; dysfunction may cause false memories

33. Neurological changes Early decline in frontal cortex, which is essential for working memory, may be cause of inability to concentrate or pay attention and difficulty in performing a task of several steps. Brain often compensates for age-related declines, using both left and right hemispheres versus younger people only using one hemisphere at a time. May be able to recover some lost memory and to improve memory, especially in fluid memory. Using previously neglected or unused abilities helps.