Download Revision - 20th Century

YEAR 11
MEDICINE REVISION
The Twentieth Century
Why did life expectancy increase in the 20th
Century?
• 1900 life expectancy of men 46, women 50. By 2000
increased to 74 for men and 79 for women
• Standard of living improved dramatically during the
20th Century as did diets
• Our economic prosperity has increased
• With technological advances has come the ability to
successfully treat far more health problems like heart
conditions
• Main causes of death in 1900 were: tuberculosis,
pneumonia and diarrhoea. In 1997 this had changed
to heart disease, cancer and stroke
Developments in the fight against
diseases
• Improved understanding of the causes of disease (as a result of the
work of Pasteur and Koch) led to a search for ‘magic bullets’ that would
cure disease
• Emil von Behring developed Koch’s work to isolate the antitoxins used
by the body to fight diptheria, then found a way to inject them to cure the
disease
• Paul Ehrlich (a member of Koch’s team) used Behring’s work to produce
a dye that only attacked the disease microbe and not harm the rest of
the body (a magic bullet).
• In 1909, Dr. Sahachiro Hata joined the team and discovered the 606th
compound that was being tested worked, this treatment was called
Salvarsan 606 and was used to treat syphilis.
• In 1932 Gerhard Domagk discovered a second magic bullet called
Prontosil used to treat blood poisoning.
• The key ingredient in Prontosil was sulphonamide and other
sulphonamide drugs were the developed to cure other infections and
diseases like pneumonia, scarlet fever and meningitis.
Vaccine Timeline
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1896 Typhoid
1906 Tuberculosis
1913 Diptheria
1927 Tetanus
1952 Whooping cough
1954 Polio
1964 Measles
1988 MMR (Measles, Mumps and Rubella)
Alexander Fleming and the development
of Penicillin
• Alexander Fleming was a chemist working at St. Mary’s Hospital in
London. In 1928 he noticed that a culture of bacteria growing on a Petri
dish was being attacked and killed by an unknown mould growing in the
same dish. He researched into this mould and found it was an antibiotic
called penicillin. Fleming published his findings in 1929 but he was unable
to get funding to develop his work and so he returned to his research.
• Howard Florey and Ernst Chain (two scientists working in Oxford) read his
research and in 1939 set up a research team to develop penicillin. In 1940
they tested it on mice and in 1941 they conducted tests on a patient but
the patient died (even though the penicillin worked) because it ran out.
• No British firm was able to create the technology required to mass
produce penicillin because the factories were being bombed in WW2 and
were busy producing other important drugs so Florey took the drug to
America to get funding for the drug. At first they were unsuccessful but
when the USA entered the war in Dec 1941 the US government was now
prepared to fund the mass production of penicillin.
• Penicillin was freeze dried and this helped it to be mass produced so that
by 1944 there was enough penicillin to be used by every Allied soldier
wounded in the D-Day invasion of Europe.
The Creation of the NHS, 1948
• During WW2 children had been evacuated from cities to the
countryside. Many people were shocked by the poverty they had
grown up in. People wanted to create a ‘New World’ with better
conditions for all.
• The bombing raids had led to many casualties and so there had
been a need to organise hospitals and medical staff during the
Second World War.
• By the mid 20th Century there was much more acceptance about the
government being involved in people’s lives.
• In 1948 Aneurin Bevan, the Minister for Health set up the NHS. It
provided the right to see a GP and to be referred to hospitals,
treatment by dentists and opticians, ambulance and emergency
treatment and health care for all.
• At first all treatments were entirely free but the expense of running
the NHS was soon much higher than expected and prescription
charges were introduced in 1951.
The discovery of DNA, 1953
• During the 20th Century scientists could take photographs of human
cells through two improvements in technology, electron microscopes
and X-rays 9using a technique called crystallography).
• Francis Crick and James Watson (two Cambridge scientists) worked
together to investigate the structure of DNA. Crick and Watson used
work by other scientists (Maurice Wilkins and Rosalind Franklin) and
discovered that genes were arranged in a double helix structure.
• 1990 The Human Genome Project, led by Watson, set out to map
the location of every single one of the 30,000 genes in the 23
chromosomes of every cell in the body. The project involved 18
teams of scientists and the first draft was produced in 2000.
• Scientists have now been able to develop certain genes that pass
on hereditary conditions. As a result, there are new techniques for
skin grafts, better production of insulin and better vaccines. There is
also better understanding of conditions such as Down’s syndrome,
leukaemia and if people are likely to develop certain forms of
cancer.
The role of science and technology
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In the 20th Century, scientific research has led to: magic bullets, antibiotics, more
vaccines, better understanding of genetics and treatments being developed for
conditions which were previously incurable.
Blood transfusions are now possible as a result of the identification of blood groups
by Karl Landsteiner in 1901and in 1916 it became possible to store blood for longer
periods as a result of the work of Francis Rous and James Turner.
The powerful electron microscope was invented in 1931. Later X-ray crystallography
was developed which was more powerful and helped the discovery of DNA.
Technology can be used to help scan patients to identify illness and disease. We now
have MRI scans which can show tumours and nuclear medicine, radioactive elements
that can be injected inside the body to keep track of what is happening inside.
X-rays were discovered by Roentgen in 1895, by 1902 they were being used to ‘burn’
and shrink tumours (radiotherapy).
Pacemakers and kidney dialysis machines keep people alive when their kidneys or
heart are not working properly.
Hypodermic needles and intravenous drips help to deliver precise doses of medicine.
Kits are available to help people to test their own blood pressure or for diabetics to
test their own blood sugar level.
Why did so many developments in
medicine happen in the late 20th
Century?
(12 marks)
• The impact of the NHS and free access to
health care by all.
• The identification of DNA in 1953 and the
Human Genome project.
• The role of science and technology.
Plenary
• Now use the interactive slides on the
power point to test what you have found
out during this revision session
20th Century Medicine
Exam Practice
Question 1 (4 marks)
What can you learn from Sources A and B about
why medicine improved during the 20th Century?
SOURCE A: The Life of Sir
Alexander Fleming (1963)
by A. Maurois
“Fleming was in his little laboratory
as usual, surrounded by
innumerable dishes…Fleming took
up several old cultures and removed
the lids. Several of the cultures had
been contaminated by mould…
…after a moments observation, [he]
said…‘That’s funny…’ On the
cultures at which he was looking
there was a growth of mould…the
colonies of Staphylococci [germs]
had been dissolved…”
SOURCE B: An American Army
Poster (1944)
Question 2 (9 marks)
• Choose one development in modern medicine
and explain its importance to advances in
medicine in the 20th Century.
• Florey & Chain’s development of Penicillin in
1941.
OR
• Crick & Watson’s discovery of the structure of
DNA in 1953.
Question 3 (12 marks)
• How important has technology been in the
development of medicine in the 20th Century?
• X-rays were discovered by Röntgen in 1895.
• The UK and US governments funded the
development of mass-produced Penicillin
during World War Two.
• Electron microscopes were invented in 1931.