Medicine 1350-Present Day Changing explanations 0f the causes of illness and disease

Ideas of the Causes of Disease 1350-1750

The Ideas of Hippocrates:• Greek Doctor (Ancient Greece around 600BC onwards.) They

believed mainly that the gods caused disease.• Hippocrates believed people became ill when the 4 humours

(liquids) in their bodies were unbalanced eg too much phlegm can be seen when people have a cold and their nose runs, or they throw up.

• Hippocratic Oath- standards of treatment, behaviour and work for benefit of patients only.

• The Hippocratic collection of books may not have all been written by Hippocrates but they are the first detailed lists of symptoms and treatments.

• Focused on recording of the progress of diseases so that doctors could see if treatments helped and use them on future patients.

• Hippocrates told doctors to use natural treatments as the causes of disease were natural eg exercise and a good diet. If necessary patients should be bled or purged.

The Ideas of Galen:• A Roman doctor who was born AD129 and educated in Greece

before going to Akexandria in Greece and then travelled to Rome becoming a surgeon at a gladiators schoo and doctor to the Emperorl.

• Believed in the 4 humours but took idea further and built on Hippocrates’ ideas with the idea of ‘opposites’ to balance them eg too much phlegm = cold so treat with something like pepper.

• Emphasised Hippocrates methods of observing and recording• Encouraged doctors to use natural treatments and exercise.• He dissected human bodies in Alexandria but had to use

animals most of the time in Rome. He proved the brain controlled the body and blood flowed in arteries.

• Galen wrote 60 books and they became the basis of medical teaching and learning for the next 1500 years.

Ideas of Causes in the Middle Ages

Multi causal approach to understanding causes of disease:

Galen’s ideas were still the basis of medical teaching- humoural theory and the theory of opposites.

Supernatural causes- Punishment by God for sins, this could be a personal cause for that individual or a punishment for society as a whole , possession by the Devil, cursed by a witch.

They also believed that the position of stars and planets could influence people’s wellbeing and that star signs as well as the four elements- earth, air, fire and water would predisposition individuals to certain tendencies in terms of ill health.

Physicians used a Latin handbook ‘vade mecum’ which means ‘Go with me.’ The manuals included urine chart and zodiac charts to help to diagnose illnesses.

Case Study 1: The Black Death, 1348. Killed about 1/3rd of the population of England.

What did they believe caused the Black Death?1. A punishment from God- he was unhappy or testing

the faithful. The Flagellants whipped themselves to ask for His mercy.

2. The position of the planets- Mars, Jupiter and Saturn.3. Bad/ poisonous air called miasma.4. Imbalance of the four humours.5. Activities of ‘outsiders’ such as Jews or witches.

The Medical Renaissance and Scientific Revolution 1450--

1750This was a time when educated people began questioning old ideas in many different scientific areas. For example Galileo studied the sun and stars and questioned whether the sun moves around the earth. He put forward the idea that the earth actually travels around the sun. Renaissance means ‘rebirth.’For the first time in medicine doctors also began to question what the Ancients had taught. Pre-existing ideas about the causes of disease began to be challenged.The printing press was also invented which meant far more people could have access to affordable texts, so aiding the spread of ideas.The Scientific Revolution saw a quest for experimenting and finding empirical evidence which triggered research into the causes of disease.

Case Study 2: The Great Plague, 1665. Killed 65,000 in

London alone.What did they believe caused the Great Plague?1. A Blazing comet was seen in the sky.2. God was punishing their sins.3. Servants brought it into their houses after the sick

breathed on them.4. It came from the sweat or stench of the sores of the

sick. Invisible creatures were carried on the air and got into peoples pores or were breathed in.

There was a reduction in the emphasis on supernatural or astrological causal explanations (1 &2) and an increased focus on common sense natural explanation of causes (3 &4)

Ideas on the Causes of Disease 1750-1860

Miasma or Bad Air- In the early 1800s people believed that nasty fumes that came off rubbish and decaying things. Growing towns were full of disease and terrible smells.

Spontaneous Generation- the idea that rubbish or decaying materials create small organisms eg a rotting orange turns into maggots and flies.

By 1861- the existence of germs had been proved and they had been linked to disease.

How was the link between germs and disease made?

Stages in the development of Germ Theory:1. Late 1600s Anthony van Leeuwenhoek made an early

microscope and noticed tiny organisms he called animalcules. He wrote 200 papaers for the Royal Society in London.

2. In 1830 Joseph Lister used new purer glass to make a microscope that magnified 1000 times without distortion.

3. In the 1850s Louis Pasteur, a French scientist, was asked by a brewing company to find out why vats of beer were going bad. He found an organism germinating (growing) in the liquid, he called them germs and realised they must be making it go bad. He showed the brewers that they could kill the organisms by boiling the liquid and solved their problem. He went on to the same for wine, milk and vinegar suppliers. In the 1860s Pasteur was asked to investigate a disease in silkworms and he found a micro-organism was causing it.

4. In 1860 the French Academy of Science organised a competition to prove or disprove Spontaneous generation. Scientists wanted to find out where micro-organisms came from. Pasteur entered the competition against Pouchet, another French scientist. Pasteur devised a series of experiments to prove microbes in the air case decay and can be killed by boiling. In 1861 Pasteur published his “Germ Theory.” He also suggested that if germs make beer go bad, maybe they do the same to animals and humans.

Pasteur’s contributionPositive:His Germ Theory suggested germs caused disease and put an and to old ideas such as the 4 humours and miasma.He developed vaccines to prevent Chicken Cholera and Rabies.He inspired Robert Koch who took up the challenge of applying Pasteur’s work to human diseases. Pasteur also inspired others to discover other bacteria eg Typhus 1880 and Plague 1894.

Limitations to Pasteur:He didn’t actually link human disease to bacteria, Robert Koch did.He only discovered the way of vaccinating against Chicken Cholera by luck, his assistant accidently used an old weakened batch of cholera matter when experimenting.Koch developed more vaccines, based on identification of specific bacteria eg He studied Anthrax and his team went on to identify the bacteria causing TB 1882 and Cholera 1883. His work on using solid cultures, instead of liquid cultures, led to the development of cures as well because they were easier to dye. He had discovered the cause of infectious diseases but not the causes of other types of illness or disease eg hereditary, environmental and lifestyle.

What factors helped Pasteur discover his Germ Theory?

Science and Technology

Chemistry had helped people to understand better how the body worked. By the 1800s purer glass meant microscopes were much stronger and bacteria could be seen clearly.

Industry A brewing company paid Pasteur to solve their problem with beer going off.The Silk Industry paid him to help with ill worms.Poultry farmers paid him to prevent Chicken Cholera.

Government

The French Academy of Science organised the competition that made Pasteur and his theory famous.The French government gave Pasteur the money he needed to hire a team of doctors to help his research.

Communications

1861 Pasteur published his theory and it immediately sold well.By the 1880s people came from all over Europe to Paris to be treated by Pasteur.

War France lost a war against Germany 1870-71. Thishis had caused bitter rivalry between the nations, Pasteur hated that Koch, a German, seemed to be getting ahead of him, so he pushed

Robert KochGerman doctor interested in Germ Theory. Bought microscope and 1875-78 studied Anthrax, a disease affecting people and animals.Impressive research led to German government giving him a job and a team of bacteriologists.What did he do? He took the organs from a sheep who died from Anthrax and found bacteria. Took bacteria sample, grew it, studied it and injected it into a mouse. Took blood from infected mouse and grew bacteria from it to check it was the same. Then injected into another mouse and continued. Repeated process through 20 generations of mice. Many scientists followed this process.Koch then developed a new solid medium to grow bacteria in. He also found a way to stain bacteria so they were more easy to study- the most important was the bacteria microbes which cause Blood Poisoning, which he stained purple. This later aided Domagk, development of Prontosil to treat blood poisoning.

The Discovery of DNAWhat is DNA? Strings inside the cells of our bodies. DNA carries the instructions for our bodies and everyone’s is different.

Early 20th Century- scientists knew about DNA but couldn’t understand how.

In 1953 in Cambridge Crick and Watson discovered the structure was a double helix joined by bases like the rungs of a ladder. They proved it was a blueprint for life passed on from one generation to the next.

Crick- trained as a physicist in London then changed to molecular biology and genetics.

Watson- an American started his research aged 15 at Chicago University.

Together they inspired each other, they were described as fun-loving, ambitious, merciless and totally honest with each other. They worked with other people at Cambridge such as Wilkins and Franklin.

What factors helped the development of DNA?

Individuals- Crick and Watson, both experts in their fields, who as individuals had adventurous characters and who were willing to go out of their comfort zones.

Teamwork- they worked with a large team of scientists. Maurice Wilkins was an expert in X-Ray photography. Rosalind Franklin developed a technique to photograph a single strand of DNA.

Earlier research and discoveries- for hundreds of years scientists knew that some illnesses were passed on through families. Scientists had used microscopes to see how cells in the body were made up.

Technology and science- scientists used new knowledge from all areas of science such as genetics and biochemistry. They also used new technology and equipment like x-ray photography and improved microscopes..

Money- funding came from two sources, governments and industry. This research was very expensive because of the types of technology and the highly skilled people it needed.

The Human Genome Project- how did they do it?

In 1990 the Human Genome Project set out to map each of the 100,000 genes in our bodies and their purpose. They complete it in 2001.

1. Research teams in 18 countries took part. (the USA, Britain , Japan, France, Canada. Each team took a different part of human DNA.

2. Money came from governments and large drug companies who hoped to profit from drugs based on DNA.

3. Computerisation was vital to analyse and record the huge amounts of data. The information found would fill over 80,000 books but could be stored on 5 CD-ROMS. The internet allowed the data to be passed around the world in minutes.

This development has aided our understanding of genetically causes diseases:Some forms of cancer, diabetes, Down’s Syndrome, cystic fibrosis, parkinson’s disease, Alzheimer’s disease.

What else have we learned about what causes disease in the 20th

Century?We now know that lifestyle is a significant cause of illness. Smoking, alcohol, sun exposure, poor diets and lack of exercise are all examplesWe are also aware of environmental causes, such as to chemicals, insecticides, pollutants etc.Heart disease, stroke and cancer are three of the biggest killers today.