Unit 2 - Chaper 3 of Text Flashcards
1
Q
What is the rate-of-living theory of aging?
A
- Organisms have only so much energy to expend in one lifetime
- Reducing one’s caloric intake can influence longevity
- The age at which a mammal becomes mature is related to longevity
2
Q
What is the cellular theory of aging?
A
- Focuses on the number of times a cell can divide before dying
- Called the Hayflick Limit, after its discoverer
3
Q
What are the 3 cellular theories of aging?
A
- The number of times a cell can divide
- Cross-linking
- Free radicals
4
Q
What are telomeres?
A
A word used to describe the tips of chromosommes
- They play a major role in aging by adjusting the cell’s response to stress and growth stimulation based on cell divisions and DNA damage
- Healthy, normal telomeres help regulate the cell division and reproduction process
5
Q
What does the enzyme telomerase needed for?
A
- Telomerase is needed in DNA replication to fully reproduce the telomeres when cells divide
- Telomerase is not generally present in somatic cells, so with each replication, the telomeres become shorter
- Eventually, the chromosomes become unstable and cannot replicate because the telomeres are too short
6
Q
How might exercise influence tolomeres?
A
Exercise may slow the rate at which telomeres shorten, which may help slow the aging process
7
Q
What is the second cellular theory of aging?
A
- Based on a process called cross-linking, in which certain proteins in human cells interact randomly and produce molecules that are linked in such a way as to make the body stiffer
- These proteins make up 1/3 of the protein in the body and are called collagen
8
Q
What purpose does collagen serve?
A
- Collagen acts like reinforcing rods in concrete
- The more cross-links there are, the stiffer the tissue will be
- Explains why tissue hardens as we age (such as heart and arteries)
9
Q
What is the third cellular theory of aging?
A
- Aging is caused by unstable molecules called free radicals
10
Q
What are free radicals?
A
- Unstable molecules which are highly reactive chemicals produced randomly in normal metabolism
- Free radicals interact with nearby molecules and problems may result
- For example … free radicals may cause cell damage by changing the oxygen levels in cells
11
Q
What are antioxidants?
A
- Prevent oxygen from combining with susceptible moleccules to form free radicals
- Common antioxidants include vitamins A, C, & E, coenzyme Q
- Ingesting antioxidants postpones the appearance of age-related diseases such as cancer, cardiovascular disease, and immune system dysfunction
- No direct evidence that antioxidants increase the life span
12
Q
What are programmed-cell-death theories?
A
- Aging may be programmed into our genetic code
- When cell death appears random, researchers believe that such losses may be part of a master genetic program that underlies that aging process
- Programmed-cell-death appears to be a function of physiological processes, the innate ability of cells to self-destruct and the ability of dying cells to trigger key processes in other cells
- Don’t know how the self-destruction process is initiated
13
Q
What mechanism is thought to underlie programmed cell death?
A
14
Q
What diseases/disorders may be examples of programmed-cell-death?
A
- Osteoporosis
- Alzheimer’s disease
Both have the ability to change brain cells
15
Q
What are the 3 general research-based approaches to slowing aging?
A
- Delay chronic illnesses of old age
- Research aimed at slowing the fundamental processes of aging so that the average life span is increased to over 110 years
- Seeking to arrest or even reverse aging, perhaps by removing damage inevitably caused by metabolic proccesses
16
Q
What 4 developmental forces interact in biological and physiological aging?
A
1) Biological
2) Psychological
3) Sociocultural
4) Life cycle
17
Q
What factors account for the changes we see as our skin ages?
A
1) Wrinkling - skin ges thinner, more fragile, and loses some of its flexibility
2) Ultraviolet rays from the sun which breaks down the skin’s connective tissue
3) Smoking, which restricts the flow of blood to the skin around the lips
18
Q
How does our hair change as we age?
A
1) Becomes thinner and loses its colour
2) Hair loss is caused by destruction of the germ centres that produce the hair follicales
3) Colour loss from a cessation of pigment production
19
Q
How do our voices change as we age?
A
- Older adults’ voices tend to be thinner or weaker
- Age-related changes in one’s voice include lowering of itch, increased breathlessness and trembling, slower, less precise prronunciation, decreased volume
20
Q
What changes in body build do we experience as we age?
A
1) Decrease in height - height remains fairly stable until the 50s, but between the mid-50s and mid-70s men lose 1 inch and women lose 2 inches. Caused by compression of the spine
2) Fluctuations in weight weight gain in middle life is often followed by weight loss in old age. People gain weight between their 20s and 50s and then lose weight through to old age. Older adults who have normal body weight at age 65 have longer life expectancy and lower rates of disability than 65 year olds in other weight categories
21
Q
What systems are involved in the changes of mobility that aging people experience?
A
- Muscles and balance
- Bones
- Joints
22
Q
What changes to muscles and balance do older people experience?
A
- The amount of muscle tissue declines with age
- At age 70 the loss is about 20%
- At age 80 the loss is about 40
- Muscle endurance diminishes with age but at a slower rate
- As lower body strength declines, the likelihood of balance problems and falls increases, as do oblems with walking
23
Q
What changes to bones do older adults experience?
A
- Bone loss begins in the late 30s, accelerates in the 50s and slows down by the 70s
- Women lose bone mass twice as fast as men
- Women have less bone mass than men so they start with less ability to withstand bone loss
- Depletion of estrogen after menopause speeds up bone loss
24
Q
What happens to aging bones?
A
- Involves a loss of bone mass inside the bone, which makes bones more hollow
- Bones become porous
- Hollow, porous bones are easier to break - when the break, it tends to be a clean break, which is harder to heal than a splintered break
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What is osteoporosis?
- Severe bone degeneration in which the loss of bone mass and increased orosity create bones that resemble laced honeycombs
- People with osteoporosis tend to develop distinct curvature in their spines
- Leading cause of broken bones in older women
- Women do not consume enough dietary calcium to bild strong bones and the decease in esrogen following menopause greatly accelerates bone loss
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What are the risk factors for osteoporosis?
1. Low bone mass at skeletal maturity
2. Deficiencies in calcium and Vitamin D
3) Deficiencies in estrogen
4) Lack of weight bearing exercises
5) Smoking
6) High protein diets
7) Excessive alcohol, caffeine, sodium
8) Some medications for asthma, cancer, rheumatoid arthritis, thyroid problems, epilepsy
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What are biophosphonates?
Medication that slows the bone breakdown process by helping to maintain bone density during menopause
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What happens with aging joints?
1) Beginning iin the 20s, the protective cartilage in joints shows sins of deterioration, thinning and becoming cracked and frayed
2) The result of tis activity is two types of arthritis:
a) Osteoarthritis
b) Rheumatoid arthritis
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What is osteoarthritis?
1. Over time the bones underneath the cartilae become damaged, which can result in osteoarthritis, a disease marked by gradual onset and progression of pain and disability, with minor signs of inflammation
2. Is a wear-and-tear disease - pain is worse when the joint is used
3. Usually affects hands, spine, hips, knees
4. Response is steriods, anti-inflammatory drugs, non-stressful exercise, diet
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What is rheumatoid arthritis?
1) Destructive disease of the joints that develops slowly and affects different joints and causes pain
2) Morning stiffness
3) Aching develops in the finges, wrists, and ankles
4) Joints swell
5) Therapy is aspirin, some anti-rheumatic drugs
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What is arthroplasty?
Total relacement of joints damaged by arthritis
32
What sorts of factors affect how older people view aging?
1) Can be dismissed as less valuable when one has gray hair, wrinkles ... can be translated into perceptions of intellectual ability as well
2) Loss of strength and endurance
3) Loss of muscle coordination
4) Arthritis limiting movement and independence
33
How does vision change with age?
1) Structural changes in the eye
2) Retinal changes
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What structural changes take place in the eye?
1) Decrease in the amount of light that passes through the eye, resulting in the need for more light to do tasks such as reading
2) The lens becomes more yellow, causing poorer colour discrimination in the gree-blue-violet end of the spectrum. The len's ability to adjust and focus declines as the muscles around it stiffen. This is what causes difficulty in seeing close objects clearly (called **presbyopia**) necessitating either longer arms or corrective lens
35
What are cataracts?
- Opaque spots may develop on the lens, which limits the amount of light transmitted.
- Often corrected by surgical removal and use of corrective lens
36
What is glucoma?
- The fluid in the eye may not drain properly, causing very high pressure, this condition can cause internal damage and loss of vision
- Fairly common disease in middle and late adulthood and is usually treated with eye drops
37
What retinal changes are associated with aging?
1) Macular degeneration
2) Diabetic retinopathy
38
What is macular degeneration?
1) The retina lines approximately 2/3rds of the interior of the eye
2) The specialized receptor cells in vision (rods and cones) are contained in the retina
3) These cells are most closely packed toward the rea and especially at the focal point of vision called the **macula**
4) At the centre of the macula is the **fovea** where incoming light is focused for maximum acuity, as when you're reading
5) With increasing agethe probability of degeneration of the maula increases
6) Macular degeneration involves the progressive and irreversible destruction of receptors
7) This disease results in the loss of the ability to see details, reading is very difficult and the TV is just a blur
39
What is diabetic retinopathy?
1) Bi-product of diabetes
2) Diabetes is accompanied by accelerated aging of the arteries with blindess being one of the more serious side effects
3) Diabetic retinopathy can involve fluid retention in the macula, detachment of the retina, hemorrhage and aneurysms
4) It takes a long time to develop, so it is most common in people who developed diabetes early in life
40
How does hearing change as people age?
The cumulative effects of noise and normative age-related changes create the most common age-related hearing problem - reduced sensitivity to high-pitched tones, called **presbycusis**, which occurs earlier and more severely than the loss of sensitivity to low pitched tones
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What 4 factors result in presbycusis?
Presby cusis results from 4 types of changes in the inner ear:
1) **Sensory** - consisting of atrophy and degeneration of receptor cells
2) **Neural** - consisting of a loss of neurons in the auditory pathway
3) **Metabolic** - consisting of a diminished supply of nutrients to the cells in the receptor area
4) **Mechanical** - consisting of atrophy and stiffening of the vibrating structures in the receptor area
42
How does an analog hearing aid work?
- A mold is placed in the outer ear to pick up sound and send it through a tube into a microphone.
- The microphone sends the sound to an amplifier.
- The amplifier enhances the sound and sends it to the receiver
- The receiver sends the amplified sound to the ear
43
How does a digital hearing aid work?
- Digital aids use directional microphones to control the flow of sound
- Compression technology allows the sound to be increased or decreased as it rises and falls naturally in the room
- Microchips allows hearing aids to be programmed for different hearing situations
- This technology uses multiple channels to deliver sound with varying amplification characteristics
44
How does a cochlear implant work?
- Implants do not make the sound louder
- The implant is a serios of components
- A microphone, usually mounted behind the ear on the scalp, picks up sound
- The sound is digitized by microchips and turned into coded signals, which are broadcast via FM radio signals to electrodes that have been inserted into the inner ear during surgery
- The electrodes stimulate the auditory nerve fibres directly
45
What is somesthesia?
- The broadest definition of somesthesia is the awareness of having a body and the ability to sense the contact it has with its surroundings.
- Our concerns at this point are about the receptors that serve to make us conscious of our bodies
46
When older people have somesthesia, what sensitivities can they develop?
- Changes in sensitivity to touch, temperature, and pain are complex and not understood
- Age-related trends are unclear in most cases
47
What age-related changes occur iin people's senses of balance?
- Dizziness and vertigo are common in older adults and increase with age, as do falls
- Changes in balance may result in greater caution in older adults when walking
48
What age-related changes occur in taste?
- Age-related changes in taste are minimal
- Many older adults complain about boring food, however, these complaints appear to be largely unrelated to changes in taste ability
49
What age-related changes occur with smell?
- The ability to detect odors declines rapidly after age 60 in most people
- Changes in smell are primarily responsible for reported changes in food preference and enjoyment
- Abnormal changes in the ability to smell are turning out to be important in the differential diagnosis of probable Alzheimer's disease, r esulting in the development of several quick tests such as the **Pocket Smell Test**
50
What age related changes occur in the cardiovascular system?
- Some fat deposits in and around the heart and inside arteries are a normal part of aging
- Heart muscle gradually is replace with stiffer connective tissue
- The most important change in the circulatory system is the hardening or stiffening of the walls of the arteries
-
51
What are 4 types of cardiovascular disease?
1) Congestive heart failure
2) Angina pectoris
3) Myocardial infarction
4) Atherosclerosis
52
What are the symptoms of congestive heart failure?
- Occurs when cardiac output and the ability of the heart to contract severely decline, making the heart enlarge, pressure in the veins increases and the body swells
- Most common cause of hospitalization for people over 65
53
What are the symptoms of angina pectoris?
- Occurs when the oxygen supply to the heart muscle becomes insufficient, resulting in chest pain
- May feel like chest pressure, burning pain, or squeezing that radiates from the chest to the back, neck, and arms.
- Pain is usually induced by physical exertion
- Most common form of treatment is nitroglycerin
- In some cases coronary arteries may need to be cleared through surgical procedures or replaced through coronary bypass surgery
54
What are the symptoms of myocardial infarction?
- Familiarly known as a heart attack
- Occurs when blood supply to the heart is severely reduced or cut off
- Mortality after aheart attack is much higher for older adults
- It starts with the symptoms like angina pectoris, but continues on - can also experience nauseau, vomiting, severe weakness, and sweating
- Older adults can have silent heart attacks, where the chest pain may be absent
55
What are the symptoms of atherosclerosis?
- Age-related disease caused by the buildup of fat deposits on and the calcification of the arterial walls
- The fat deposits interfere with blood flow through the arteries
- Excessive fat deposits may develop from poor nutrition, smoking, lack of exercise
56
What is a cerebrovascular accident?
- When severe atherosclerosis occurs in blood vessels that supply the brain, neurons may not receive proper nourishment, causing them to malfunction or die - a condition called **cerebrovascular disease**
- When the blood flow to a portion of the brain is completely cut off, a cerebrovascular accident or **stroke** results
57
What are some of the causes of cerebrovascular accidents or strokes?
- Clots that block blood flow in an artery or the actual breaking of a blood vessel, which creates a cerebral hemorrhage
- The kind of stroke and the possibility of recovery depends upon the specific part of the brain involved
58
What are 2 common problems following a CVA/stroke?
1) Aphasia - problems with speech
2) Hemiplegia - paralysis on one side of the body
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What are the risk factors for CVA/stroke?
1) Age
2) Male
3) African American - due to a higher propensity to hypertension, poorer quality and less access to health care in general
4) High blood pressure
5) heart disease
6) Diabetes
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How is CVA/stroke treated?
- Use of clot dissolving drug tissue plasminogen activator (tPA)
- tPA is the only approved treatment for CVAs caused by blood clots
61
What is hypertension?
- High blood pressure - when blood pressure increases become severe, define as 140mm Hg or more systolic pressure (the top number in a blood pressure reading) or 90mm Hg or more diastolic pressure (the lower number in the reading)
- Blood pressure is the force of blood pushing against the walls of arteries as it flows through them.
- Arteries are the blood vessels that carry oxygenated blood from the heart to the body's tissues.
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What are the risk factors for hypertension?
1) Age - risk of high blood pressure increases as you age
2) Race - High blood pressure is particularly common among blacks
3) Family history - runs in families.
4) Overweight or obese
5) Not being physically active
6) Using tobacco
7) Secondhand smoke
8) Too much salt (sodium) in your diet
9) Too little potassium in your diet
10) Too little vitamin D in your diet
11) Drinking too much alcohol
12) Stress
13) Certain chronic conditions such as kidney disease and sleep apnea.
63
What changes are seen in the respiratory system as we age?
- Rib cage and air passageways become stiffer, making it harder to breath
- Lunds changing going from pink to gray, caused maily by breathing carbon particles
- Maximum amount of aire we can draw in declines
- Rate at which we exchange oxygen for carbon dioxide drops as the membranes of the air saces in the lungs deteriorate
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What is chronic obstructive pulmonary disease (COPD)?
- Family of diseases that include chronic bronchitis and emphysema
- Smoking is the most common cause of COPD
- Can also be caused by second hand smoke, air pollution, and chemicals
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What is emphysema?
- Most serious kind of COPD
- Characterized by the destruction of the membranes around the air sacs in the lungs
- Is irreversible
- Creates holes in the lungs, which reduces the lung's ability to exchange oxygen and carbon dioxide
- Chronic bronchitis becomes more prevalent with age
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What changes occur in the female reproductive system as we age?
- Climacteric - a time during which a major biological process occurs during which a woman will pass from her reproductive to nonreproductive years
- The syndrome of endocrine, somatic, and psychic changes occurring at menopause in women.
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What is perimenopause?
- Perimenopause means "around menopause" and refers to the time period during which a woman's body makes its natural transition toward permanent infertility (menopause). Perimenopause is also called the menopausal transition.
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What is menopause and what symptoms define it?
- Ovaries stop releasing eggs
- Gradual loss of monthly periods
- Decrease in estrogen and progesterone levels
- Changes in reproductive organs
- Changes in sexual functioning
- Can include hot flashes, night sweats, sleep problems, mood changes, more urinary infections, pain during sex, difficulty concentrating, vaginal dryness, less interest in sex, increase in body fat around the waist
69
What is the position on women taking hormone replacement therapy (HRT) to address the symptoms of menopause?
- Reduces some of the unpleasant symptoms of menopause
- May protect against cariovascular disease
- Significant increased risk for breast cancer
- Reduced hip fractures
- Lower rates of colorectal cancer
70
What changes are seen in women's reproductive organs as they age?
- Vaginal walls shrink and become thinner
- Size of the vagina decreases
- Vaginal lubrication is reduced and delayed
- Greater difficulty achieving orgasm
71
What changes can be seen in the male reproductive system as men age?
- Gradual decline in testosterone
- Decline in the quantity of sperm
- A man is only half as fertile at 80 as he is at 25
- With increasing age the prostate gland enlarges, becomes stiffer, and may obstruct the urinary tract
- Men report less perceived demand to ejaculate and need more time to get stimulated and achieve orgasm
- Viagra may help with the problems of erections
72
What imaging techniques are use to examine the brain?
1) Computerized tomography - CT
2) Magnetic resonance imaging - MRI
3) Positron emission tomography - PET
73
What is computerized tomography (CT)?
Images created by passing highly focused X-rays in various directions through the patient, with computers creating a three-dimensional image
74
What is magnetic resonance imaging (MRI)?
- Images produced by reorienting the body's molecules with large and very powerful magnets; detectors pick up radio frequencies that are shot through the body section under study
- Can be used to study some physiological processes.
75
What is positron emission tomography (PET)?
- Images created by injecting a radioactive isotope and passing positrons (subatomic particles) through the body from various directions, detecting them, and analyzing them.
- Very useful technique for studying brain activity; typically by examining glucose metabolism
76
What are neurons?
Changes in the brain occur mainly at the level of individual brain cells called neurons
77
What are the parts of a neuron?
1) Cell body
2) Dendrites
3) Axon
4) Terminal buttons
78
What are some of the characteristics of neurons?
- We have 1 trillion neurons of different sizes and shapes
- Neurons can grow in size and complexity across the life span
- Like heart muscle cells, neurons cannot regenerate - once a neuron dies, it is lost forever
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80
What are neurotransmitters?
- Chemicals called neurotransmitters are released at the terminal branches and carry the information signal to the next neuron's dendrite
- The neurotransmitters are necessary for communication between neurons because neurons do not physically touch each other
- The gap between the terminal branches of one neuron and the dendrites of another, across which neurotransmitters travel is called the synapse.
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