Assessment task: Extended response
A neurological epidemic
Alzheimer’s disease and Parkinson’s disease are two conditions that most
commonly occur in older people and involve progressive degeneration of parts
of the nervous system. As the proportion of older people in the Australian
population increases, the number of people suffering from these diseases will
increase. Sufferers often have the disease for many years before it causes
death.
Apart from the gradual, painful and confusing loss of physical and mental
faculties for a patient, the terrible progression of the disease is one that places
enormous emotional, physical, social and financial pressure on family and
caregivers. There is currently no cure for either of these conditions. However,
research is being undertaken to improve the treatment of these conditions and
hopefully find a cure.
Read the summary of background information below. This summary relates to
the diseases of Alzheimer’s and Parkinson’s. Use this information to answer the
questions that then follow.
Parkinson’s disease
What is it?
Parkinson's disease is a chronic, degenerative neurological disorder.
Who does it affect?
Mainly older people are affected by Parkinson’s disease. Approximately 1 in
every 100 Australians over 60 years old has the disease. While the average age
of onset is 60, in an estimated 510% of patients, the onset starts by the age of
40.
What are the symptoms?
Symptoms include: shaking (tremors), slow movements, muscle stiffness,
stooped posture, impaired speech and a blank facial expression.
What has gone wrong in the nervous system?
There is a deficiency in the neurotransmitter of dopamine in Parkinson’s
patients. This is caused by the progressive degeneration of nerve cells in the
basal ganglia of the brain. Without this chemical symptoms begin to appear.
How can it be treated?
Parkinson’s disease can be managed by medication that relieves the
symptoms. However, there is no cure and it will eventually result in death.
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Alzheimer’s disease
What is it?
Alzheimer's disease is the most common form of dementia and accounts for
between 50% and 70% of all cases. It is a progressive, degenerative illness that
attacks the brain.
Who does it affect?
It is usually people over 65 years of age that develop Alzheimer’s disease. The
number of people diagnosed with dementia is projected to increase, with the
number of cases rising from 245,400 in 2009 to 1.13 million cases by 2050 in
Australia.
What are the symptoms?
In the early stages the symptoms of Alzheimer's disease can be very subtle.
However, it often begins with lapses in memory and difficulty in finding the right
words for everyday objects. Other symptoms may include:
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persistent and frequent memory difficulties, especially of recent events
vagueness in everyday conversation
apparent loss of enthusiasm for previously enjoyed activities
taking longer to do routine tasks
forgetting well-known people or places
inability to process questions and instructions
deterioration of social skills
emotional unpredictability.
Symptoms vary and the disease progresses at different rates according to the
individual and the areas of the brain affected. A person's abilities may fluctuate
from day to day, even within the one day, becoming worse in times of stress,
fatigue or ill-health.
What goes wrong in the nervous system?
Neurons in the brain of Alzheimer’s sufferers shrink or disappear. Abnormal
material builds up as ‘tangles’ and ‘plaques’ around the remaining neurons
located usually in the hippocampus and cerebral cortex areas of the brain. This
disrupts messages within the brain and damages connections between the
neurons. The neurons eventually die and this means that information cannot be
recalled or assimilated. As Alzheimer's disease affects each area of the brain,
certain functions or abilities are lost.
How can it be treated?
At present there are no drugs that have been shown to conclusively delay or
halt the progression of the disease. A small number of drugs are available that
have shown some beneficial effects.
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1. a) On this diagram of the brain, label which areas are affected by
Alzheimer’s disease and Parkinson’s disease.
b) High-profile people have often been leaders in raising awareness of
medical conditions. For example, American actor Michael J Fox has
contributed enormously to the raising of public awareness for Parkinson’s
disease. Soon after his own diagnosis in the late 1990s Fox established
and funded a research foundation to raise money and awareness for
Parkinson’s research.
Use the following website to answer the question below:
http://www.michaeljfox.org/research.cfm
Search for ‘research area position papers’ to find out more about the current
research into possible treatments for Parkinson’s disease.
Also go to <http://www.epidna.com/> to find information on the treatment of
Alzheimer’s disease.
The evidence from early testing suggests that cell replacement therapy could
provide a very effective treatment for neurological disorders like Parkinson’s
and Alzheimer’s disease. For each disease, outline which cells will be involved
and the effects of the treatment.
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2. a) Describe the chemical and electrical changes which occur in a neuron
when it transmits a message. The diagram below shows the ‘resting
state’ before the nerve impulse is initiated. Your answer could include a
diagram to show the ‘excited state’.
b) What is the function of the sodium pump in the conduction of nerve
impulses? Which energy source is used to operate the pump?
c) How does an impulse cross the gap between the axon of one neuron and
the dendrite of the next nueron. Use diagrams to help with your answer.
d) Curare is described as a nerve poison. Outline where this poison is found
and how it affects the transmission of a nerve impulse.
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3.
Draw a diagram of the nerve pathway for the pupillary reflex that occurs
when you walk from a dimly lit hallway into a darkened room in which you
switch on the light.
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