Transcript Ageing and medical technologies

Ageing and medical technologies
HBS3B
Revision questions
Draw a spinal reflex arc
Explain the importance of spinal reflex arcs
Revision questions
Draw a spinal reflex arc
Explain the importance of spinal reflex arcs
They allow rapid response to harmful events
Usually movement out of danger is initiated before the message about the danger reaches the
brain.
Life expectancy
People today have a longer life expectancy than ever before. Men can
expect to live to 78 and woman to 82. This means that an increasing
proportion of our population is considered to be “aged”.
This has a number of implications for our society including increased
number of retirees, increased need for financial support and health
care for the aged. Increased need for hospitals, aged care services
eg nursing homes, retirement homes, hospices, etc
Effects of ageing 1
Ageing or senescence affects all our body systems. Some of the effects of
ageing include:
Skin and hair
With age skin generally becomes thinner. Hair becomes white or grey and skin
may show colour spots because cells producing pigment become less
active. Baldness may occur in men and women and sweat glands become
less active.
Muscles, bones and joints
There is a decrease in cell size, numbers and fibre in the muscles, causing them
to lose mass and strength.
Bones become lighter and more brittle because calcium leaches out (especially
in females due to low oestrogen, and in smokers). This makes people more
susceptible to fractures.
Joints become less flexible and arthritis occurs because of wear and tear on the
joints
There are changes in posture, and height decreases, because of osteoporosis,
joint damage and muscle wastage.
Digestive system
Teeth fall out and muscles of the jaw become weaker. Digestive glands slow
down, and digestion becomes slower.
The smooth muscles in the digestive tract work less efficiently as they weaken
therefore causing problems such as constipation and indigestion.
Effects of ageing 2
Circulatory system
The efficiency of the heart and circulation decreases with age. The pumping of
the heart decreases with age, and less blood is pumped because the mass
and strength of the heart is reduced. Blood flow to tissues decreases because
of reduced efficiency of the heart and narrowing of arteries.
Blood pressure tends to rise, and there is a greater risk of cardiovascular
disease.
Bruises become more common because of thinner walls to capillaries and thinner
skin.
Respiratory system
With age breathing efficiency is decreased. This is a result of decreased
elasticity in the lungs and reduced strength of respiratory muscles. Gas
exchange in the lungs is reduced.
The result of this decreased breathing efficiency on the heart is put under further
pressure.
Effects of ageing 3
Brain, nerves and senses
Overall the functioning of the nervous system decreases
There is a decrease of total brain cells and their fibres during ageing. This results in loss of
memory and some co-ordination.
There is a certain amount of sensory loss with age.
Sounds are lost in the low frequency range. The tone and sense of words become difficult
to hear.
Vision becomes less acute. Generally speaking, people tend to need glasses for close work
eg reading. Along with this, night vision grows weaker.
Smell and taste senses decrease and balance becomes less reliable.
Touch becomes less acute as does pain, pressure and heat and cold perception. As a
result of this some injuries such as falls are more common.
Endocrine system
Many glands decrease their activities and secretions. In particular, the ovaries in females
cease secreting oestrogen and progesterone. This is associated with the cessation of
ovulation and is called menopause. The lack of the sex hormones can lead to
osteoporosis and hormonal imbalances
Males have a reduction in testosterone production with a decrease in sexual drives.
The reduced activity of the thyroid gland, coupled with the loss of body mass and
circulatory changes means that older people are more susceptible to temperature
changes.
Many older people may become diabetic, and need to change their diets and/or exercise
regimes to deal with this.
Effects of ageing 4
Excretory system
Kidney function changes in old age because of wear and tear, causing
breakdown of the filtering units. One outcome of this is an increase
in urinary problems eg kidney failure.
Immune system
The thinness of the skin and slowing down of glands means that it is
easier for germs to enter the body. Once entered the body, these
germs are less likely to be destroyed, as the immune system is less
effective. Thus older people are at greater risk of diseases such as
colds and flu.
People appear to age at different rates. Some people appear old and
decrepit in their fifties, while others are active into their nineties.
Research suggests that lifestyle has a big impact on the ageing
process.
Effects of ageing 5
From this it can be seen that the elderly need access to treatments or
devices that help them compensate for the changes occurring in
their bodies eg mobility aids, prostheses (eg glasses, hearing aids,
false teeth, bionic ears, artificial joints), pacemakers, medical
treatments (eg insulin, anti-inflammatories) and dietary
supplements.
Some behaviours or dysfunctions that were once considered due to old
age are now recognised as symptoms of disease, some of which
can be treated or prevented.
In order to increase the chances of a healthy old age we should have a
healthy lifestyle when young – eg healthy diet, regular exercise,
don’t smoke, reduce alcohol, etc, and continue this as you age –
particularly exercise. As we get older we should keep physically and
mentally active and continue to socialise.
Diseases of old age 1 - Arthritis
Arthritis is inflammation of a joint or joints.
There are several types, including rheumatoid, osteoarthritis and gout.
Factors that increase the risk of arthritis include diet, exercise, obesity, age,
damage or injury due to over use (eg sport)
Symptoms of arthritis include:
Rheumatoid: severe form involving inflammation, swelling, pain and loss of
function of joints. It starts with inflammation of the synovial membrane,
which grows to form abnormal tissue called pannus. This pannus grows
over the articular cartilage, destroying it, and fills up the cavity, thus
restricting movement of the joint.
Osteoarthritis: degenerative disease due to wear and tear on the joints. The
articular cartilage deteriorates, and bony growths develop in the joints, thus
decreasing mobility, and causing pain.
Gout: inherited genetic disorder causing an accumulation of sodium urate
crystal in the joints, thus causing pain, swelling and eventual destruction of
joint tissues.
Treatment for arthritis include: drugs – painkiller, steroid, anti-inflammatory,
physiotherapy, diet & exercise regimes, joint replacement surgery (in severe
cases)
Diseases of old age 2 - Osteoporosis
Osteoporosis is a reduction in bone mass leading to bone weakness
and increased risk of fractures. It is seen more often in females than
males due to the hormonal changes seen in menopause.
Factors that increase the risk of osteoporosis include age, low calcium
or vitamin D levels, lowered oestrogen levels (especially seen after
menopause in women and in smokers), smoking, lack of exercise
Symptoms include: thinner bones, more fractures, ‘dowagers hump’
and decreased height (due to collapsed vertebrae in upper spine)
Treatments include: increased dietary calcium and vitamin D
supplements (these have most impact in younger people – so its
important to start building bone mass young) and weight bearing
exercise
Diseases of old age 3 – Alzheimer’s
Alzheimer’s disease is an irreversible, progressive brain disease that
slowly destroys memory and thinking skills, and eventually even the
ability to carry out the simplest tasks. In most people with
Alzheimer’s, symptoms first appear after age 60.
Alzheimer’s disease is the most common cause of dementia among
older people.
Dementia is the loss of cognitive functioning -thinking, remembering,
and reasoning - to such an extent that it interferes with a person’s
daily life and activities
Although we still don’t know what starts the Alzheimer’s disease
process, we do know that damage to the brain begins as many as
10 to 20 years before any problems are evident.
Tangles begin to develop deep in the brain, in an area called the
entorhinal cortex, and plaques form in other areas. As more and
more plaques and tangles form in particular brain areas, healthy
neurons begin to work less efficiently. Then, they lose their ability to
function and communicate with each other, and eventually they die.
This damaging process spreads to a nearby structure, called the
hippocampus, which is essential in forming memories. As the death
of neurons increases, affected brain regions begin to shrink. By the
final stage of Alzheimer’s, damage is widespread and brain tissue
has shrunk significantly.
Factors that increase the risk of Alzheimer’s include genetic,
environmental, and lifestyle factors.
Diseases of old age 3 – Alzheimer’s 2
Symptoms include: memory loss, often followed by confusion,
mood swings, aggression and general withdrawal but can
vary depending on the degree of damage suffered
Mild Alzheimer’s Disease
As Alzheimer’s disease progresses, memory loss continues
and changes in other cognitive abilities appear. Problems
can include getting lost, trouble handling money and paying
bills, repeating questions, taking longer to complete normal
daily tasks, poor judgment, and small mood and personality
changes. People often are diagnosed in this stage.
Moderate Alzheimer’s Disease
In this stage, damage occurs in areas of the brain that control
language, reasoning, sensory processing, and conscious
thought. Memory loss and confusion increase, and people
begin to have problems recognizing family and friends.
They may be unable to learn new things, carry out tasks
that involve multiple steps (such as getting dressed), or
cope with new situations. They may have hallucinations,
delusions, and paranoia, and may behave impulsively.
Severe Alzheimer’s Disease
By the final stage, plaques and tangles have spread throughout
the brain and brain tissue has shrunk significantly. People
with severe Alzheimer’s cannot communicate and are
completely dependent on others for their care. Near the
end, the person may be in bed most or all of the time as the
body shuts down.
Diseases of old age 3 – Alzheimer’s 3
Treatments include a number of strategies - including
helping people maintain mental function; managing
behavioral symptoms; and slowing, delaying, or
preventing the disease.
A nutritious diet, physical activity, social engagement,
and mentally stimulating pursuits can all help
people stay healthy.
New research suggests the possibility that these
factors also might help to reduce the risk of
cognitive decline and Alzheimer’s disease.
Scientists are investigating associations between
cognitive decline and vascular and metabolic
conditions such as heart disease, stroke, high
blood pressure, diabetes, and obesity.
Understanding these relationships and testing them in
clinical trials will help us understand whether
reducing risk factors for these diseases may help
with Alzheimer’s as well.
Diseases of old age 4 – Parkinson’s
Parkinson’s disease is a degenerative
disorder of the brain for which the
cause is not known.
A section called the substantia nigra
(which is responsible for making the
neurotransmitter dopamine) becomes
severely depleted of dopamine and
so the pathways responsible for
coordinating body movements
(including the basal ganglia, the
substantia nigra and the cerebellum)
become disrupted causing the
abnormality of movement.
The symptoms gradually get worse over
time
Factors that increase the risk of
Parkinson’s include family history
and exposure to environmental toxins
Diseases of old age 4 – Parkinsons’s 2
Symptoms include abnormalities of movement,
involving one or more of the following
Tremor - an involuntary rhythmic shaking in an
extremity (like an arm or leg), or in the face. A
Parkinson's tremor is worst at rest and gets better
when the extremity is moved; it often disappears
during sleep. In the hand, the thumb may move
back and forth against the other fingers – Parkinson
called this motion 'pill rolling'.
Bradykinesia - slowness of movement. People with
bradykinesia seem to freeze: they have trouble
initiating movements and they're slow in changing
position. Their voice also sounds monotonous, and
they have a fixed, staring, unblinking expression.
They stoop, and when they walk they shuffle.
Muscular rigidity - muscles – especially in the arms,
shoulders and neck – become stiff, rigid, and
resistant to being passively moved. They may move
in a series of ratchet-like steps: this is called
'cogwheel rigidity'.
Treatments include drugs to increase dopamine levels,
and modification to the household to help sufferers
cope.
Quality of life and euthanasia
Some people suffer from diseases for which there is no hope of recovery, and in
which their quality of life is so poor they wish to end their life.
Quality of life refers to a person’s enjoyment of life and includes factors like
mobility, pain and ability to participate in desired activities.
Euthanasia refers to is the bringing about of the death of a person (usually
because of severe pain or suffering due to a terminal illness).
Some issues relating to euthanasia include:
At present it is illegal to perform, or aid people to perform euthanasia (assisted
suicides) as it is considered a crime (either murder or suicide).
Suicide still carries a criminal penalty for those who are unsuccessful.
The Northern Territory did bring in a bill to enable euthanasia of the terminally ill,
but that was overturned by the federal government.
It is acceptable to with hold medical support (eg life support machines), where
patients, or family, have given consent, and thus allow a person to die
naturally.
In the traditional beliefs of the Christian, Jewish and Muslim religions, the taking
of another’s life is considered wrong.
The euthanasia issue raises some moral problems as well - there is a fear that it
could be misused against a section of the community (eg Hitler’s program to
wipe out the Jews), or against elderly/ill people who have no ability to choose.
Arguments for and against euthanasia
Arguments for voluntary euthanasia
include
• Choice is a fundamental right
• Only a patient can decide whether
their suffering is too great
• Patients are shown more respect
when they can choose to die
• There is a large financial and
resource burden in keeping a
seriously ill person alive
Arguments against voluntary
euthanasia include
• Human life is sacred – no-one has
the right to end life
• It puts doctors and other health
care workers in a position where
they have to go against their
training (and possibly beliefs)
• Patients may not be competent to
make the decision
• There may be a cure in the future
• There may be pressure to end life
for convenience or financial
reasons
• Euthanasia may fail and cause
further suffering
Biomedical technology
Biomedical technology refers to devices and machines used in the medical diagnosis or
treatment of injuries or disease. These can be
mechanical eg prosthetic limbs, bionic devices,
external eg supports, bionic limbs
internal eg artificial joints, bionic ear
Some specific examples include:
Devices to increase mobility or treat disorders of the musculoskeletal systems eg mobility aids,
artificial limbs, artificial joints
Devices to aid deficiencies of hearing or vision eg glasses, hearing aids, bionic ears and eyes
Devices to treat cardiovascular disease eg pacemakers, artificial valves, transplants (heart or
valve)
Dietary supplements or fortified foods eg vitamins, fish oils, added nutrients in some foods (eg
thiamine, vitamin D or folic acid), fluoridation of water
Pharmaceuticals and drug delivery systems eg analgesics, anti-inflammatories, statins,
antibiotics, insulin, tablets, patches pumps and implants
Biological technologies eg tissue regeneration, spray on skin, transplants, grafts, stem cell
therapy
Physiotherapy involves manual therapies (eg massage, stretching manipulation), use of
technologies (eg diathermy, ultrasound, laser or transcutaneous electrical nerve stimulation TENS) and other procedures (eg splinting, strapping) and can be used to reduce pain,
restore muscle strength and increase mobility
Bionic devices are electromechanical devices used to replace dysfunctional body parts
Examples include limbs, ear (cochlear implant) and eye (still being developed)