Ch. 3: Physical Changes Associated with Aging Flashcards
Aging theories fall into two main categories:
- Programmed theories
- Error theories
Programmed aging theories
- aging is genetically programmed to occur with the passage of time
- programmed aging theories propose that aging and death are built into the hard-wiring of all organisms and therefore are part of the genetic code
Error/random aging theories
- aging is the result of random damage that occurs with the process of living
- aging is caused by environmental damage to systems in our bodies. This damage accumulates over time
Gompertz function
(ex of programmed aging)
- plots the relationship between age and death rates for a given species
- species live to different maximum ages (life span)
- ex: relationship between the age in days of mice and rats and the rate of dying per day
- the fact that different species have different functions supports the notion of genetic contributions to longevity
“Good genes gone bad” theory
(ex of programmed aging)
- evolution has selected for species that are vigorous through the period of optimal sexual reproduction and then are less important once that period is passed
Replicative senescence
(ex of programmed aging)
- the loss of the ability of cells to reproduce
Telomere theory
(ex of programmed aging)
- each cell replication reduces the length of telomeres until the chromosome’s tips are no longer protected
Hayflick limit
Autoimmune theory
(programmed aging)
proposes that faulty immune system attacks the body’s cells
Cross-linking theory
(error/random aging)
- In cross-linking, the strands of the collagen molecule start to become intertwined, causing the molecules to become increasingly more rigid and smaller
- results from exposure to certain kinds of sugars which leads to glycation, causing formation of advances end-products (AGE’s)
Free radical Theory
(error/random aging)
- unstable oxygen molecules are produced when cells create energy
- they seek out and bind to other molecules
- the attacked molecule then loses its functioning
Antioxidants can fend off free radicals
Error catastrophe
(error/random aging)
- proposes that random mutations in mitochondrial DNA cause irreversible damage that accumulates over time
Wear and Tear Theory
(error/random aging)
- proposes that our bodies wear out due to use over time
Two types of skin aging and their definition
- Intrinsic aging: gradual irreversible changes in structure and function that occur due to the passage of time
- Extrinsic aging: aging due to external factors such as exercise, diet, exposure to sunlight, and smoking
Androgenetic Alopecia
- (Male/Female-Pattern Baldness)
- 30-50% of men are affected by this by age 50
Greying pf the hair due to reduced _______________, which occurs earlier in Caucasians than those of African and Asian descent
melanin/melanocytes
This happens 5-10 years later in African and Asian descent
What causes hair to grow everywhere but the head as we age?
Hormonal changes
Presbyphonia
refers to age-related voice changes including :
- changes in pitch (lower pitch in women, higher pitch in men)
- reduction in volume and projection
- tremor/shakiness in the voice
- reduced vocal endurance
- often happens around age 60
age related vision changes are due to structural changes like
- older adults need more light than younger adults. They get 1/3 of a light because the max diameter of pupil is smaller in older people
- increased sensitivity to glare
- decreased visual acuity
- dark and light adaptation takes longer
- poorer color discrimination for short wave lengths
- focusing near-far and far-near takes longer
Presbyopia
- means old eye
- not considered a disease
- primary aging
- happens to tall people later
- start early as 35 years old
- late 40s
- gonna have difficulty on focusing things that are close up
- stiffening and thickening of the lens & atrophy of ciliary muscles
- inability to accommodate
- normal accommodation is lost in presbyopia
Cataracts
- abnormal vision change
- cause scattering of light rays
- can interfere with color vision
- cause limitations in daily activities
- possible causes: heredity, prior injury, disease, sunlight, smoking
- surgery is a highly effective treatment
Glaucoma
- abnormal vision change
- build up of pressure inside the eye
- often involves gradual onset
- treatment not always possible, but many can be treated with eye drops
- group of conditions involving damage of optic nerve
What are the other 2 vision changes that are not normal part of aging
- Age-related macular degeneration
- Diabetic retinopathy: possible long term complication of diabetes
Presbycusis
- inability to hear high-pitched tones due to changes in the cochlea
- by age 70, half of older people have presbycusis
Audiogram
- hearing test
Presbycusis impact for speech understanding
- some speech sounds will be harder to distinguish
- some populations will be harder to understand: women & children because they have high-pitched voices
Hearing threshold is worse for men than women. Why?
- type of jobs they have
Communication strategies for talking to older adults
- look directly at the person
- make sure you and the other person are in enough light
- turn down background noises
- don’t chew gum or food
- keep the voice low
- enunciate carefully
- do not talk to the person as of he or she were a child
- provide context so the listener knows what you’re talking about
- note whether the other person is responding to you
- maintain positive and patient attitude
Anosmia
- changes in smell
- has been described as the “canary in the coalmine” with regards to overall physiological declines and death
- also an indicator of Alzheimer’s disease & memory impairment
- usually happens by age 80
Changes in taste with old age
- the research on changes in taste perception with age is contradictory
- some studies indicate no decline, and other studies indicate declines but not for all types of taste