Chapter 1 Flashcards
• Chronological Age
measured by years
Agerasia
person looks/is fitter than their age
Progeria:
Werner/Hutchinson-Gilford, premature ageing
• Social Age:
What is considered socially acceptable behavior at what age
• Antediluvian ageing myth/hyperborean ageing myth:
beliefs of race of people in ancient times/far away lands that had incredibly long lifespans
• Today:
retirement ether positive “golden years” or negative, forced removal from work
• Pensions:
late 19th century, German invention
• Inter alia
less strong and less easy to retain pension makes room for younger workers
• Adolphe Quetelet
early attempt at anthropometry “old age begins at 60-65 years”
• Threshold age
60-65 years significant changes in physical and mental functioningused by most gerontologists
• Young old,
old old
• Third age
still active
fourth age
dependent on others
• Functional age
: chronological age at which a particular level of skills is found (controversial)
• Distal ageing effects
: distant events during ageing, e.g. less mobility because of childhood polio
• Proximal ageing effects
more recent events during ageing, e.g. broken leg
Universal Ageing
: All people, e.g. wrinkles
• Probabilistic ageing
likely but not universal, e.g. arthritis
• Primary ageing:
age changes to the body
• Secondary ageing
occur frequently, not necessarily
• Tertiary ageing
rapid deterioration before death
• Quetelets definition
old age “begins” at roughly 60-65 years, but no given point when person automatically becomes old, chronological age is arbitrary measure
Prevalence of Ageing- the greying population
- Prehistoric era: old age extremely rare
- Until 17th century only 1% of population over 65
- By 19th century: aprox. 4%
- Britain today: 16%
- Old age today commonplace experience
- Life expectancy: how much longer can a person expect to live
• Different measurements for life expectancy
either mean time left for people to live in one age group or median time people don’t live longer, fewer people die young
• Life expectancy 1400, 1841, 1981: 35, 40, 71
• Reasons for better life expectancy
; antibiotics, disease prevention, better aesthesia, inoculation, clean water, hygiene….
• Best practice life expectancy
highest life expectancy figure to be found in any country in the world at a particular point in time has risen linearly aprox. 3 month each year for 160 years
- Rising life expectancy largely due to low childhood mortality, only small increase in older pople e.g. infectious disease strikes for first time in childhood
- Life expectancy today is only a prediction, not certain e.g. obesity crisis could have effect (negative) or gene therapy (positive)
• Longevity fan:
: life expectancy graphs produced by different predictive models would fan out the further into the future the lines would go
data
- Estimated peak of old people in population: 17 million, 25% of total population in 2060 (UK)
- Biggest change in oldest old people: 85 years or older
- 70% of todays Western population can expect to live past 65, 30-40 % past 80
- Move from pyramidal society to rectangular society
Prevalence of Ageing-Variations
- Larges differences in life expectancy: industrialized vs. developing countries
- In 2010: world life expectancy at birth: 69 years, developed: 77, less developed: 67, 55 in least developed
- Principal cause of death in western world increasingly chronic
- Once nutrition and perinatal issues in developed countries under control, life expectancy should sky rocket
- Life expectancy also dependent on SES, supportive communities
• Fountain of youth- myth in almost every culture
• Tithonus myth:
got older but could not die suffering, not desirable
• Harvard alumni Study
exercise strongly equated with longevity
Facts about longevity
- Diet
- Having friends
- Winston Churchill argument
- Environmental factors + genetics
- Shorter people have higher life expectancy than taller people
- Fruit flies: over 500 genes involved with life expectancy
- IGF1 pathway growth factor with hormonal operations
- Number of men and women roughly equal until 45 years, at 80 years: ratio 4:1 not because of stress factors, difference also in other species
The cost of living longer
- 75% of “extra time” for old people is spent suffering from one or more physical disabilities
- Active life expectancy: the expectant remaining years of functional well-being in terms of the activities of daily living, for noninstitutionalized elderly people
- Final 10% of life is lived with appreciable disability
• Expansion of morbidity theory
people buy extra life by suffering more
• Compression of morbidity theory
period of severe disability can be compressed into shorter time frame
Causes of biological ageing
- Biological age: state of a persons body
- Anatomical age: state of bone structure, body build…
- Carpal age: state of the wrist (carpal) bones
- Physiological age: state of physiological processes, e.g. metabolic rate
- Post-developmental: physical decay and weakness
- Body’s cells: over a period of 7 years, most die and are replaced or lost
- Cell Decline after 30
• Somatic mutation theory of ageing
: cells are replaced by inferior copies
• Autoimmune theory of ageing
ageing attributable to faults in immune system
• Cellular garbage theory
: ageing because of toxins produced as by-product of normal cellular activity
• Free radical theory
damage caused by chemical by-products of cell’s metabolic processes
• Other effects: disease, stress, toxins
• Hayflick phenomenon:
cells only reduplicate a limited number of times (Hayflick limit) cells preprogrammed to die
• Telomere
(sequence of DNA at end of chromosomes), shoelace metaphor (keeps DNA together, gets shorter every time it duplicates, prevents cell from getting cancer still debated
• Programmed senescence (vergreisung) theory
ageing caused by evolutionary causes, designed to happen debatable, most animals in the wild die before reaching old age
• Mutation accumulation theory
: ageing effects happen because they are not elected against by evolutionary forces
• Antagonistic pleiotropy theory
like mutation accumulation theory, also: some genes may be of advantage in early age bot not older age
• Fruit fly experiments
: creating a disadvantage in early life was met with an advantage in later life (higher life expectancy)
• Disposable soma theory of ageing
: reproduction is everything, reproduction organs are kept in best condition on expense of other (somatic) cells in body
The ageing body
- Skin and muscles become less elastic, loss of efficiency in mitochondria
- Urinary system slower less efficient in filtering toxins
- Gastrointestinal system less efficient in extracting nutrients
- Less muscle mass
- Less oxygen
- Weaker heart , hardening and shrinking of arteries
- changes have effect on brain functions in extremis: stroke
- Elderly people fall asleep after meal: oxygen level constricted because all energy goes to digestive system, not enough oxygen to stay conscious
- Toxins eave the body slowly overdose, delirium
- Decline in gastrointestinal system malnutrition
- Lack of Vitamin B12 Dementia like symptoms
- Depression because of signs of ageing
The ageing sensory systems
• Starts in early adulthood
Vision
- 1/3 of people over 65 have disease affecting vision
- Decline in accommodation (focus on different distances)
- leads to presbyopia long sightedness
- Caused by ageing lens losing elasticity
- Loss of acuity (ability to see objects from a distance
- 75% of elders need spectacles
- Loss in Contrast sensitivity function (CSF): tiny image invisible in low contrast but visible in high contrast e.g. lads to older people falling often
- Visual threshold (dimmest light that can be seen) increases with age
- Adjusting to low level lighting (dark adaptation) decreases with age
- Reduced ability to recover from glare
- Change in color perception: older people perceive world more yellow,
- blues and purples become harder to discriminate (only in 80s)
- size of visual field diminishes, cannot move eyeball as far up as younger people
- loss of peripheral vision (onset in middle age)
- Vison problems not purely ageing issue, starts earlier in life
- Charles Bonnet Syndrome: visual hallucinations, no other mental symptoms 11% of people with impaired vision
- 7% of 65-74 year-olds and 16% above 75 blind or severely visually impaired
- Reasons: cataractslens becomes opaque, glaucomaexcess fluid accrues in eyeball, pressure destroys nerve
- Macular degeneration (sharpest spot)
- Diabetic retinopathy damage to blood vessels of eye because of diabetes
- all these diseases can be prevented
Hearing
- Hearing loss at 50
- 1/3 of people in 70s and 80s need hearing aid, ½ o people 80 and older
- Presbycusis age related hearing loss (ARHL): 50% of people over 65 have some degree of hearing loss, other figures: 60-70%
- Old people cannot hear high frequenciesmost of speech is in high frequencies understanding people is impaired
- Sound localization impaired
- Leads to impairments when doing other tasks (lower mental capacity)
- Causes of hearing loss: noisy environment, genes, diet, free radicals, cardiovascular and general health
- Men’s hearing declines faster but sensitivity to higher frequencies remains better
- Ageing ear lobes increase in size by several millimeters
- Bones of the middle ear stiffen (trough calcification or arthritis)
- Auditory nerve diminishes in size
- Ability to detect silent gaps between auditory signals affected by age rather by state of hearing loss
- Level of hearing loss does not account for all changes in auditory skills in later life
- Worsening of pitch discrimination, sound localization and perceiving timing information
- Tinnitus: 10% of older adults
- Age x complexity effect: the more complex the speech signal, the more disadvantaged are older people, BUT: almost no difference to younger people when signals are familiar phrases or expressing familiar concepts
- Comprehension of emotional content of speech is unrelated to level of hearing loss
- Hearing loss=emotional burden
Taste
- 4 types: bitter, sweet, sour, salty
- Decline in sensitivity to the four types
- inconsistent studies about what declines faster
- Bad at either choosing or metabolizing healthy diet
- 5% of 65-74 year-olds in study (Clarke et al.) had Vitamin B12 deficiency, 10% over age 75
Smell
- Little change in very healthy older adults
- Most older adults at least some decline (due to illness)
- Studies suggest changes because of changes in diet and cognitive decline
- Profound loss in people with dementia and Alzheimer’s
Touch
- Older people have higher touch threshold (firmer stimulation of skin before touch is detected)
- Sensitivity to temperature of objects decrease
- Cause: thinner skin, decline of number of touch sensors in skin
Pain
sensory receptors, but other researchers have fund no such evidence
• Prevalence of pain-providing conditions increases with age emotional meaning of pain may differ between ages
• Older brain not good at integrating several strands of sensory information into a cohesive whole
Neuronal changes in later life
• MRI studies: brain volume decreases, ventricular system increases in size
• Biggest losses in temporal and frontal cortex, putamen, thalamus, accumbens
• cause: shrinking of neurons and lowering of connections between neurons
• Huge variability between individuals
• Loss in intellectual skills correlated to loss in brain volume either because of physical decline or because of neuroplasticity (brain shrinks because intellectual skills are not used anymore)
• fMRI: many memory tasks are less lateralized
• brain changes in size and function
Possible Causes: not enough practice, decrease cerebral blood flow, neurons dying, not functioning properly , infarcts: mini strokes, blood-brain-barrier declines, toxins reach the brain (has been linked to dementia, decreased cognitive abilities, decreased ability to recover from strokes)
