modern medicine 1900-present

• Modern Ideas about the Causes of Disease
• Lifestyle were all found to impact on health
• The Germ Theory was a major breakthrough in identifying the causes of disease, but identifying viruses was difficult as they were caused by microbes called viruses, which were too small to see under a microscope
• Ivanovsky investigated mosaic, a disease affecting tobacco plants, and found the cause was an extremely small microbe


  1852
• Martinus Beijerinck found these microbes had different properties to bacteria and labelled them viruses


  1898
• The discovery of viruses led to their successful treatment, as unlike bacteria, viruses aren't destroyed by antibiotics</b>
• DNA has given an insight into Genetic Conditions
• DNA


  The chemical instructions that plan out human characteristics, like sex and hair colour, stored in cells
• DNA structure


  A double helix, a kind of spiral that can reproduce by splitting
• Francis Crick and James Watson first described the structure of DNA


  1953
• Knowledge of genetic conditions has improved diagnosis and treatment of them
• Lifestyle Factors can increase the Risk of some Diseases
• Lifestyle factors linked to health conditions

  • Smoking causing lung cancer
  • Obesity increasing heart disease and diabetes
  • Drinking too much alcohol causing liver disease
  • Overexposure to UV radiation causing skin cancer
• Developments in science and technology since 1900 have shown that there are multiple causes of disease, including viral infections, genetic mutations and lifestyle choices
• Causes of illness discovered by 1900

  • Bacteria
• Causes of illness discovered since 1900

  • Viral infections
  • Genetic mutations
  • Lifestyle choices
• New Causes of disease demanded new ways of diagnosing them
• Blood Tests allow doctors to Diagnose more illnesses
• Blood tests


  Used to test blood groups, cholesterol levels, DNA, and for certain cancers
• Advances in computers allowed doctors to use ultrasound scanning, CT scans, and MRI scans to create detailed images of the body
• Improvements in medical scans have enabled earlier diagnosis and intervention
• Patients can now Monitor their own bodies using devices like blood pressure and blood sugar monitors
• Alexander Fleming discovered Penicillin, the first Antibiotic
• Fleming's discovery of Penicillin


  1. Saw soldiers die of septic wounds

  2. Identified antiseptic substance lysozyme

  3. Noticed fungus killing bacteria in culture dish

  4. Identified the fungus as Penicillium notatum

  5. Published findings but unable to develop further
• Florey and Chain found a way to Purify Penicillin
• Florey and Chain's work on Penicillin


  1. Devised freeze-drying purification technique

  2. Produced penicillin for first clinical trial

  3. Patient recovered then died when penicillin ran out
• Florey took penicillin to America for Mass Production
• Mass production of Penicillin


  1. American firms initially not keen until US joined WWII

  2. British firms also started mass production by 1943

  3. Cost fell after the war making it more accessible
• Fleming, Florey and Chain were awarded the Nobel Prize in 1945
• Penicillin is still used today to treat a range of bacterial infections
• Other antibiotics were discovered after 1945
• Paul Ehrlich discovered the first Magic Bullet-Salvarsan 606
• Ehrlich's discovery of Salvarsan 606

  1. Discovered dyes that could kill malaria and sleeping sickness germs

  2. Searched for arsenic compound to target syphilis bacteria

  3. Compound 606 appeared to work, first used in 1911
• Gerhard Domagk found the second Magic Bullet-Prontosil
• Domagk's discovery of Prontosil

  1. Found red dye prontosil stopped streptococcus microbe multiplying

  2. Gave daughter prontosil when she caught the disease, she recovered

  3. Active ingredient identified as sulphonamide, leading to more sulphonamide drugs
• Radiotherapy and chemotherapy have been introduced to fight cancer
• Targeted therapy has been used to fight cancer since the late 1990s
• Blood Transfusions have solved the problem of Blood Loss
• Development of blood transfusions

  1. Landsteiner discovered blood groups, allowing safe transfusions

  2. Sodium citrate discovered to stop blood clotting, enabling stored blood

  3. First blood bank set up in 1917, British National Blood Transfusion Service established in 1946
• Transplants have been made more Successful