10 Greatest Discoveries in Medicine

Each one of our ten greatest discoveries in medicine has been a huge leap forward in both the understanding of, and application to human well being. By pushing the boundaries of knowledge, these breakthroughs have saved countless lives throughout the world.

1 – Human Anatomy

10 greatest discoveries in medicine - human anatomy.

Early knowledge of human anatomy was often comparative, based on animal dissection. It dates back to Egyptian times but it was Greek ideas that came to dominate medicine. Galen was the key figure with many of his ideas persisting for over 1000 years. Leonardo da Vinci managed to dissect 30 human cadavers until he was banned from doing so by the Pope. He never published his work and it wasn’t until centuries later when his notebooks were found that he had made remarkably advanced drawings including cross sections and views from various angles.

The world-changing moment came when Belgian physician, Andreas Vesalius, published a treatise ‘On the Structure of the Human Body‘. As professor at Padua University, one of his friends was an executioner so he was able to access a supply of bodies for dissection. His work challenged the work of Galen in many ways, made anatomy more accessible and established dissection as an integral part of medical training.

2 – The Circulation of Blood

10 greatest discoveries in medicine - circulation of blood.

Prior to Galen, it was believed that arteries carried air round the body. Based on his work on fresh animals, Galen disposed of that notion and correctly said that blood flowed through arteries. But he didn’t quite get it right as he believed blood ebbed and flowed. It was down to William Harvey early in the 17th century to enlighten the world.

After studying the beating hearts of animals that he dissected, he came to realise that ‘blood flowed in a circle’. One of his crucial findings was that there was a system of one-way valves in the circulatory system which allowed blood to flow only in one direction – along the arteries from the heart and back to the heart in the veins. What we take for granted was truly revolutionary and Harvey himself realised the importance of this discovery. This knowledge led to the development of many life-saving techniques including clamps for blood vessels, which reduced dramatically blood loss during surgery.

He published his work ‘On the Motion of Heart and Blood‘ in 1628 in Frankfurt where he was astute enough to know that the annual book festival would ensure the rapid dissemination of his findings.

3 – Blood Groups

10 greatest discoveries in medicine - blood groups.

In Vienna in the early 20th century, there was a vogue for blood transfusions as they were seen as being beneficial and invigorating. Unfortunately, some recipients were dying rather than being invigorated. Austrian biologist and physician Karl Landsteiner made it his business to understand why this happened.

He mixed various samples of blood and observed the outcome. In many cases, the two blood samples mixed perfectly well, however, in others, the blood clotted. After further investigation he discovered that antibodies on one kind of blood bound themselves to antigens (proteins) on the surface of the red cells, thus binding them together into clumps. With careful and methodical observation, Landsteiner discerned 4 distinct blood types – A, B, AB and O. The importance of this was that he realised that transfusions should be carried out using the same blood group.

Since then, further work has identified many more types of blood and the Rhesus factor. The latter is important to women having children. The blood of a Rhesus negative mother can become sensitised to the blood of a Rhesus positive foetus, at best, harming the developing child, at worst, killing it.

4 – General Anaesthetics

10 greatest discoveries in medicine - general anaesthetics.

Prior to the development of reliable general anaesthetics, surgery was an absolute last resort, many people preferring to die rather than suffer the pain of an operation. The search for anaesthetics can be traced right back to the dawn of civilisation and whilst Europe in the middle ages was a brutal and painful place, in the middle East, during the Islam Golden Age, there are records of both oral and inhaled general anaesthetics being used.

The Western world started to catch up around 800 years later. Various scientists had discovered and experimented with substances like nitrous oxide, chloroform and ether. Humphrey Davy noted the analgesic effects of nitrous oxide but the first recorded modern use of a general anaesthetic is 1804 in Japan where a general anaesthetic based on a Chinese formula was used to perform a mastectomy.

In 1840s America, touring lecturers indulged in ‘ether frolics’ where a member of the audience was treated with ether or nitrous oxide and then proceeded to make an idiot of themselves in front of the audience. Two young men who attended these lectures realised the importance for medicine. William Clarke and William Morton administered ether to a patient for a tooth extraction. Some years later Morton demonstrated the use ether as a general anaesthetic for the removal of a tumor from a man’s neck.

Famously, Queen Victoria used chloroform as a painkiller during the birth of Leopold and for a while, chloroform superseded ether. When the toxicity of the latter was discovered, surgeons went back to using ether.

5 – X-rays

10 greatest discoveries in medicine - x-rays.

Surgery had always been a bit hit-or-miss as the surgeon had no way of looking into the body other than by making an incision. Wilhelm Röntgen changed all that in 1895.

Whilst working with cathode rays, one of his experiments involved enclosing his cathode ray tube in a cardboard cover in a blacked-out room. He hen noticed that a small screen coated in barium platinocyanide was glowing. He knew this could not be the cathode rays since they were blocked by the cardboard. He had discovered something new, rays that could pass easily through solid objects. He called them X-rays (X for unknown). A week or so later he took a photographic image using X-rays of his wife’s hand. On seeing her bones, she exclaimed ‘I have seen my own death’ as the only time you saw a skeleton was after death.

Röntgen’s discovery was immediately and universally accepted, without any controversy, ultimately leading to the development of medical scanners of great complexity such as CAT scanners.

6 – Germ Theory

10 greatest discoveries in medicine - germ theory.

This is yet another of those greatest discoveries in medicine that took the work of many for someone eventually to reach enlightenment; in this case, it was Frenchman Louis Pasteur. The first main step on this road came in Austria in 1846 when Ignaz Semelweis was puzzled by the fact that the mortality rate of women after childbirth was 3 times greater in wards run by doctors rather than midwives.

The deaths were caused by ‘childbed fever’, an infection of the female reproductive tract. He realised that the doctors often carried out an autopsy on dead women and then went straight on to deliver the next child without washing hands and he wondered if something invisible was being transferred on surgeons hands. So he instructed his team to wash their hands in a chlorinated lime solution after all operations and the death rate plummeted to well below that of the midwives.

Medical thinking of the time had no idea of the link between bacteria and diseases. Illness was regarded still in ancient Greek terms of being an imbalance in the individual. There was no germ theory so his ideas were simply dismissed by the profession and people went on dying needlessly.

Along came Pasteur. He was working in the beer and wine industry and trying to work out how to prevent wine from turning sour. He twigged that microorganisms caused the problem and he developed the system that now bears his name – pasteurisation – in which heat is used to kill microorganisms. So was born the germ theory that microorganisms caused disease and not some sort of imbalance in the individual. This paved the way for Joseph Lister to introduce antiseptic working practices for the medical profession.

7 – Vaccination

10 greatest discoveries in medicine - vaccination.

Credit for this is always accorded to Edward Jenner, the English Physician who popularised vaccination against smallpox. It was well known that milkmaids were immune to the disease smallpox, however, they were susceptible to a mild form called cowpox. Jenner suggested that the pus in the cowpox blisters protected them so he took a sample, injected it into a local child and waited. The child duly developed cowpox. Jenner waited till that had cleared up and deliberately exposed the child to smallpox and waited again. The boy did not develop smallpox.

Jenner was the 7th person to have done this but the others gained little recognition. 22 years earlier, Dorset farmer Benjamin Jesty, had protected himself, his wife and child against smallpox in the same way. Finally, in 1805, his work was accepted and he was given a testimonial and a pair of gold mounted lancets (Jenner received in total 30,000 GBP). He was also taken to have his portrait painted which now is owned by the Wellcome Foundation.

8 – Vitamins

10 greatest discoveries in medicine - vitamins.

Before 1747, long distance sailors had limited access to fresh fruit and vegetables and were subject to the upleasant disease, Scurvy. This is characterised by poor healing of wounds, severe gum disease and eventually death. In 1747, Scottish doctor James Lind discovered citrus fruits solved the problem so British naval ships began to carry stocks of lemons and limes, hence the ‘Limeys’ nickname for the British navy sailors.

It wasn’t until the next century that science began to understand why this worked. In the 1880s, a Russian surgeon, Nikolai Lunin, fed mice on an artificial diet of the known constituents of milk. They died, but mice fed on milk itself thrived. From this, he corectly concluded that there must be unknown substances in milk that are essential for life. Further research involving brown and white rice, chickens and the Japanese Imperial Navy led British biochemist, Frederick Hopkins to say pretty much the same as Lunin, but with reference to food in general. The race now was on to find these substances.

The first came in 1910 when a Japanese scientist Umetaro Suzuki identified aberic acid. A poor translation from Japanese into German failed to emphasize it was a newly discovered nutrient so its significance was overlooked. It was re-discovered by Polish biochemist Kazimierz Funk who also coined the name ‘vitamine’ (contraction of ‘vital amine’ as it was indeed an amine). Despite the fact that not all ‘vitamines’ were not amines, the name stuck, the ‘e’ was dropped and gradually the other vitamins were isolated and identified.

9 – Penicillin

10 greatest discoveries in medicine - penicillin.

Whilst studying bacteria, on the morning of September 28th 1928, Alexander Fleming noticed that a mould had grown on one of his staphylycoccal culture plates. Around the mould was an area where the bacteria had been unable to grow. Fleming deduced the mould must have excreted something that inhibited bacterial growth. Since the mould was a Penicillium strain, he dubbed the mixture of nutrient broth plus mould ‘Penicillin’.

Fleming was unable to find anyone to help him isolate the active ingredient so his work went largely unnoticed. However, one person who did take some notice was Cecil Paine, a pathologist working in Sheffield. He managed a few succesful cures and some failures using Penicillin. He wasn’t the first to experiment with the curative properties of Penicillin, that honour goes to French physician Ernest Duchesne who used P.glaucum against E. coli and cured a few guinea pigs of typhoid.

It could all have ended there but a team lead by Australian Howard Florey successfully treated mice.  They then moved on to treat a policeman, who died – they did not have enough penicillin to treat his infection fully. Unlike their predecessors, the Florey team persisted and developed a mass-production method. This had a poor efficiency but nevertheless, they went to the USA to see if they could interest any drug companies. Merck agreed to the production and by March 1943, had produced two doses. In June of the same year, they had managed to make ten doses; production was certainly proving difficult.

After a massive search, a mouldy melon was located in Illinois that provided the perfect penicillium strain for mass production and by the end of WWII, over 600 billion doses were produced.

10 – Insulin

10 greatest discoveries in medicine - insulin.

Our final greatest discovery in medicine is that of insulin.

In the 19th century, it was discovered that the bodies of diabetes sufferers had something in common – areas of the pancreas (islets of Langerhans) that produced insulin were damaged. Several groups worked on the extraction of the substance these ‘islets’ produced but failed.

So we end up in 1920, Canadian researcher Frederick Banting persuaded the university of Toronto to provide him with research facilities, 10 dogs and an assistant, Charles Best. They succeeded in extracting insulin (called ‘isletin’ at the time) and injected it into a dog whose pancreas had been removed. They found that the extract kept the dog alive.

The next step was to do the same for humans. They discovered insulin from calves of cows was similar to human insulin. The first trial was on a young lad who lay dying in Toronto Hospital. The first injection contained insulin that was far too impure and he suffered an allergic reaction. So they re-purified their sample and a second injection was successful. Their piece de resistance was to go round a whole ward of dying children in the same state, giving insulin injections. Before they had fnished, the first ones injected were already coming out of their comas.