Doctors must have a good knowledge of human anatomy which can only be learned by dissecting human cadavers. The procurement of human bodies in sufficient numbers has always been a problem for medical schools, and the history of this procurement has been bizarre.

The great majority of the bodies that came available were those of the poor and the indigent. The fact that many of those people lived and died under extreme negative conditions that had consequences in their internal anatomies meant many textbook descriptions of internal organs were actually descriptions of abnormal structures.

To will your body to a medical school for use by medical students is a high-minded act, but one that few are willing to contemplate. However, many more people are prepared to be high-minded nowadays than in ages past when bodies were "supplied" almost entirely by the poor and the indigent. Reliance on the bodies of the poor has a long history. In the 16th century King Henry VIII decreed that the bodies of executed prisoners should be given to anatomists for dissection. The main intention was to further punish the victims - the dissections were carried out publicly and the remains were tossed to the dogs.

Public executions could not keep up with the demand for bodies as medical schools grew in numbers. The 18th century saw the birth of the bodysnatcher. These gentlemen plundered fresh graves. The graves of the poor were the easiest targets. Wealthy people could afford to post guards on graves.

Grave-robbing has a very bad reputation, and deservedly so. But isn't it curious that the anatomists who bought the bodies from the grave-robbers are not viewed with anything like the same distaste as the grave-robbers?

Things went from bad to worse. There was the celebrated case of William Burke, who took to inviting beggars to his home for dinner, then murdering them and selling their bodies.

Eventually, governments took action and many decreed that the bodies of people who died destitute would be handed over to the anatomists. This satisfied medical demand for bodies and put paid to the grave robbers.

Many poor people in ages past lived lives of considerable stress and deprivation, causing various glands in the body to become enlarged. Since anatomy was learned almost entirely from their cadavers, the size and shape of these swollen glands were taken as their normal configuration.

Consequently, when a person who had lived a life of what we would consider average comfort was autopsied, some glands looked oddly undersized and this was attributed to a disorder. A new "disease" termed idiopathic adrenal atrophy was defined, i.e. adrenals shrunk for some unknown cause. This disorder flourished early in the 20th century until eventually the cause was accurately diagnosed - normal living.

Another example of falsely identifying abnormal organs as normal concerned the thymus gland. A person who lives in a chronic state of stress over-secretes hormones from the adrenal glands, which become enlarged. One of the consequences of this is that the immune system is inhibited.

A gland essential for the immune system is the thymus, located in the throat. The thymus can shrivel to a tiny size in a person under chronic stress. Again, these tiny thymus glands were interpreted as normal by anatomists and large thymus glands were diagnosed as enlarged.

Around the 1930s physicians noted a new disorder - sudden infant death syndrome (SIDS). Seemingly healthy infants would die mysteriously in their sleep. Autopsies revealed that these babies had "enlarged" thymus glands.

A credible theory was proposed to the effect that SIDS was caused when an enlarged thymus pressed down on the trachea (air tube going from nose to lungs), suffocating the infant. The routine advice from paediatricians was that infants' throats should be irradiated to shrink the enlarged thymus.

This treatment became popular and persisted into the 1950s in the US. The treatment had no effect on SIDS: the enlarged thymus was in fact normal and the norm of a small thymus was deduced from autopsies of children who had died from chronic illness.

Unfortunately, the radiation treatment had a nasty side-effect. Just beside the thymus gland is the thyroid which helps to control our rate of growth and the rate at which our metabolism ticks over. Irradiating the thymus induced tens of thousands of cases of thyroid cancer.

This story illustrates the importance of getting the basic things right. We would be better employed spending more time on the simple basics and less time rushing headlong down every dimly-lit avenue of innovation that beckons.

This column was inspired by an article by Robert M. Sapolsky (The Sciences, Sept/Oct 1991).

William Reville is a Senior Lecturer in Biochemistry and Director of Microscopy at UCC