William Harvey’s Dissected Family

Having commented about how the Achilles tendon came to be named following the dissection by Philip Verheyen (1648-1710) of his own amputated leg, I came across a note I copied from an unknown source about William Harvey (1578-1657), the discoverer of the circulation of the blood. It reads…

'Harvey's quest for knowledge and lack of human material led him to dissect his own sister and father when they died. Surprisingly, Harvey did not like the idea of having his own body dissected after his death and requested his corpse be wrapped in lead to protect it from other anatomists'.

Upon checking this, I have found that there is a story in circulation (pun intended) about Harvey having dissected his own father and sister—or at least having witnessed their dissections. However, there also appears to be no historical evidence that this was ever, in fact, the case. Beware.

Eric Laithwaite and the Lesson of the Gyroscope

Somebody who frequently appeared on television when I was a boy was the electrical engineer Professor Eric Laithwaite (1921-1997). This was in the late 1960s and early 1970s. This was in the era before the emergence of today's more ‘telegenic’ popularisers of science. I don't think anybody would have described Laithwaite as 'telegenic;' he seemed to be a rather gruff, although not unfriendly, character with a strong Lancashire accent. He and those scientists with whom he often appeared had a much greater sense of gravitas about them than current science presenters, and yet they were still able to appeal to a young audience. Indeed, he twice gave the Royal Institution Christmas Lectures in 1966 and 1974.

One of Laithwaite's interests—highlighted in his 1974 lecture—was the properties of gyroscopes. This seems to have been sparked by his meeting with an amateur inventor called Alex Jones. Laithwaite's pronouncements on gyroscopes were controversial at the time—and probably still are. This is because what Jones had built, based around a gyroscope, seemed to contradict certain laws of physics—not least Newton's Third Law of Motion (the one about there being to every action an equal and opposite reaction).

Be that as it may. Something I took from hearing about this was from what happened next. In order to find out how he had been able to build such a machine, Jones took it to pieces. Then, upon reassembly, he found that it did not behave in the way originally observed! (At least, this is how I understand the story; I only remember these few details.)

If there is a moral to this story, it is about the dangers of reductionism. As a whole, Jones's machine behaved in a certain way—or at least seemed to. To try to understand this machine as a whole, what would have been the best approach? As it turned out, taking it to pieces was certainly not the ideal. Indeed, was it even necessary to disassemble it? The machine had been built from a known set of parts put together according to certain plans. Were there not also other recollections about its construction that would have made the assembly of a replica possible? Why take apart when one could make an exact copy? Then, should both machines behave in the same way, one’s initial findings would be on an even firmer foundation.

Here, I am interested in the human body. How might we understand it better without taking it apart? What lessons might we draw from the story of Jones and Laithwaite?

Achilles’ tendon

Although referring to a well-known character from the Trojan War of the 12th or 13th century BC, the thick tendon behind the ankle only came to be known as the Achilles’ tendon after the late 17th century. The oldest-known written record of the tendon bearing the name is from 1693 by the Flemish/Dutch anatomist Philip Verheyen (1648-1710). In his widely used anatomical work, Corporis Humani Anatomia he described the tendon's location and said that it was commonly called 'the cord of Achilles'.

The tendon had been described as early as the time of Hippocrates, who described it as the 'tendo magnus' (Latin for 'great tendon'), although there is some debate about this. From what I can ascertain, Hippocrates did not call the Achilles tendon the 'tendo magnus'. He referred to it instead as the 'neura megala', which translates as 'great tendon'. The term 'tendo magnus' was used by later anatomists prior to Verheyen. Another associated term was 'chorda Hippocratis' (Latin for 'Hippocrates' string').

In using the term Achilles’ tendon, Verheyen is referring to the mythological account of Achilles being dipped into the River Styx by his mother Thetis while being held by his heel. Where the water wetted him, his body was rendered invulnerable. As the heel by which his mother held him was not touched by the water, it was his one vulnerable spot (hence the association of the phrase 'Achilles' heel' with having a specific vulnerability). Achilles was eventually killed by a poison dart, which struck him in the heel. 

What is particularly interesting about Verheyen’s naming of this tendon is that he is reputed to have done so having dissected his own amputated leg. There is even a painting of him doing so (below).That leg was not deliberately amputated for purposes of dissection, of course, but the exact reason for its loss I have been unable to find out. Similarly, I have been unable to find out who painted the painting. One source describes it as “Anonymous. From the collection of Pieter Deheijde.”

There is also a suggestion that Verheyen lost his leg fairly early in life. If so, that makes this painting look somewhat anachronistic and calls into question this fascinating story.

Humpty's state… and mine

In what sort of state was Humpty after his fall?

I know how all the king’s horses and all the king’s men must have felt. How does one go about putting all Humpty’s bits back together again? I have a similar problem. I have many years of notes and reflections relating to the scientific study of the human body. It’s fun looking through and re-thinking old ideas, but how do I make them intelligible? How do I make sense of them? How might I share them? (Clearly this is an outlet.) It’s an on-going and perhaps unending quest but it is not pointless. Although I have not mastered its use yet, with the advent of AI, I have at least an extra tool at my disposal. Indeed, it has already drawn from some of my collections ideas that had not previously occurred to me.

Humpty’s was a quite different and much bigger problem. He was lying there in fragments. Had it been possible to put him together again, then what? Assuming that, in his fragmentary state, these fragments were each still alive in their own way, he was dead. Would a simple reassembly have brought him back to life again? Was there still enough life in the fragments that reassembly was really just a matter of reattachment of parts so that everything might proceed as before? Could Humpty have continued with his life where it had left off? A defibrillator would surely have been necessary to restart his heart in a coordinated way, assuming that that had not been fragmented too. But what about restarting his brain? Can a brain, fragmented or not, be restarted once stopped? 

Can one pass from being a single complex organism to one in fragments and back again? Sponges (the sea creature, not the plastic foam, of course) can be made to do this. It is possible to pass a sponge through a fine sieve and for the bits to spontaneously coalesce. The bits of sponge will not be in precisely the same place as before, but the sponge is able to carry on as before. Or should that be, the individual sponge cells will carry on (unless disrupted by the sieving)?

Heart muscle has been shown to do something similar. It is possible to chemically separate heart muscle cells and produce a soup of individual cells. If left alone, these heart cells are able to spontaneously coalesce—albeit into a blob of cells rather than a fully formed heart with different chambers, etc. Not only that, but throughout the process, the dispersed heart cells continue to beat with their own individual rhythms. Once they have coalesced, this beating becomes synchronised, and the blob beats as a single entity.

My notes are seeking a conceptual wholeness; Humpty was seeking the restoration of his physical wholeness. Each, I suspect, has something to say to the other. Part of my task is finding out what that may be.

Flatus

This topic crosses certain boundaries. It is a topic of physiological interest but not one discussed in polite company. As such, it serves as a lesson in not allowing politeness to encumber academic investigation.

That the bowel produces gas is well known to everybody. Nobody alive has even not produced bowel gas. In the healthy individual, this gas is a natural byproduct of the activity of the symbiotic bacteria living in our large intestines. When teaching the large intestine, the production of this gas may be commented upon (in passing, pun intended), but this is not always the case. That this gas is often wilfully vented inevitably goes unremarked. This is despite the interesting fact that even when suffering from diarrhoea, we are often able to vent gas (albeit carefully) while successfully containing the liquid faeces. This suggests that the anal sphincter possesses a certain dexterity—for want of a better word. It is a pity that this dexterity is not more widely appreciated and discussed in lectures.

I remember a rather uncouth boy at school who deliberately broke wind in class one day and remarked to those sitting around him how nice he found its smell and how nice they ought to find it too! They did not; quite the opposite, of course. This does raise the question of why he liked it and the others did not.

I do not know why, but I do think it to be a reasonable question to pose. That we find some of the smells produced by others unpleasant may have something to do with the 'Yuk factor' or, to put it more scientifically, 'the wisdom of repugnance'. This is the notion that certain things that we find inherently unpleasant are also potentially harmful to us. In turn, the reaction to the unpleasantness prevents us from incurring any harm. Avoiding contact with faeces is obviously to our benefit. This may perhaps extend to the smells associated with them. Their smells may alert us to potential harm.

At the same time, being able to smell one’s own bowel gas when passed does provide us with a feedback mechanism of sorts. It does allow aspects of the chemistry of the bowel to be scrutinised consciously and, perhaps more importantly, subconsciously. Does bowel chemistry in terms of the gas smelt influence subsequent dietary choice?

That bowel gas has an odour, and the differing reactions to that odour are something socially unconscionable even in the lecture theatre. It is my contention that there are no barriers to what is allowed in the lecture theatre or indeed any forum of academic discourse. All academic discourse seeks to explore ideas, often rigorously interrogating their flaws and weaknesses. However, promoting and trying to inculcate ideologies and doctrines is another matter. That and ordinary academic discourse should not be confused.

To that end, I did once have a professor who discussed defecation and its... (left us call them for politeness) concomitants. There is a lot of feedback to be had from the act of defecation. What this tells us about the state of our bowels is important to recognise and should not be ignored out of mere politeness. Bowel cancer has become a prominent topic in the UK in recent years. Now is clearly a time to relax certain inhibitions on what is discussed.

NB As the length of the Wikipedia entry on flatulence demonstrates, there is much more to bowel gas than one realises. I was surprised; it is worth a look.

Cisterna Chyli

I previously mentioned the LOS (Lower Oesophageal Sphincter) and how once it had no place in the human anatomical canon but now does. What of things being the other way round? That is, are there any structures that exist in the human anatomical canon but not in the human body? If there is a candidate, it is the cisterna chyli. This is (supposedly) an expanded portion of the lower end of the thoracic duct where a number of lymph vessels converge, delivering their contents on the way to being returned to the circulation.

The cisterna chyli was first described in the 1650s by Jean Pecquet (1622-1674), a French anatomist whose work relied upon dissections using dogs rather than human cadavers. Notwithstanding this, the cisterna chyli went on to find its way into human anatomy texts. When eponymes were popular, textbooks of human anatomy often referred to it as the 'cistern of Pecquet' or 'reservoir of Pecquet'. There it has remained. However, it is not, in fact, a structure often found in humans.

Studies using human material suggest that the cisterna chyli may only be present in about 14% of individuals. (This I obtain from a footnote to the 35th Edition of Gray’s Anatomy.) A number of variants in the arrangement of the lymph vessels in the area of the lower thoracic duct/cisterna chyli are well known. In fact, the area is often highlighted as being one of considerable anatomical variability.

Surely, if the cisterna chyli is not present in the human body and that area is known for being very variable, how does it persist in the textbooks? Wouldn’t generations of medical students looking for it not point out to their teachers that it wasn’t where they were told to find it?

In my experience, generations of medical students dissecting the posterior abdominal wall and not finding it have blamed their poor dissecting skills rather than the textbooks and dissecting guides. Their teachers have similarly assumed these sources to be unerring and their students clumsy.

If correct, how does an occurance rate of 14% qualify something to be taught as canonical? When performing statistics on experimental data, 95% is the confidence level at which a result is deemed statistically significant. Occurring in the human body at a rate of 14% is well below 95% and hardly implies that it is ‘typical’ or ‘ordinary’… or canonical.

Note on Jean Pecquet

I once read that Pecquet’s particular research interest was the physiological effects of alcohol. In an era when investigators were not averse to experimenting on themselves, it appears that Pecquet did the same… and died of the effects of his own research.

More on Medawar

In a previous post (The Mind of a Human Biologist), I mentioned how Peter Medawar (1915–1987) had provided a foreword for the book entitled Human Biology and had given his opinion as to what it was. Why had the authors agreed to asking Medawar to perform that task?

I suspect that it was something about Medawar that made him the ideal person to write the foreword. He was not simply a prestigious name to be called upon to give a new book cache. He represented something of what a Human Biologist ought to be. He was a Human Biologist before the term became popular. That included him also being something of a philosopher.

He championed the ideas of Sir Karl Popper (1902–1994) and, in particular, the hypothetico-deductive method (or model) of doing science. Philosophy is not a popular discipline among practicing scientists. One reason for this seems to be that scientists view philosophers as speculating without an evidential base, whereas they see themselves as basing their thinking firmly on objective data. Philosophers do not collect data. Instead, they interrogate the thinking that arises from those data.

I suspect that there may also be some degree of prejudice born of interdisciplinary rivalry, which is inculcated into the minds of all young would-be scientists. (Unless, of course, they are strong-willed enough to make up their own minds.)

Medawar not only championed Popper’s ideas; he presented Popper’s hypothetico-deductive system in terms accessible to scientists. They did not have to resort to Popper’s original philosophical writings. This Medawar did through lectures and essays written for a broad audience. His Jayne lectures of 1968, published as ‘Induction and intuition in scientific thought’ (published separately in a slim volume and later collected within Medawar’s ‘Pluto’s Republic'), are a case in point. These are writings accessible to all thinking persons.

Richard Dawkins (1941–) once referred to Medawar as "the wittiest of all scientific writers." Medawar’s scientific writing was certainly not devoid of humour. His ‘Aristotle to' Zoos'—subtitled A Philosophical Dictionary of Biology and co-authored with his wife—was, by all accounts, written amid howls of laughter as he thought of a witty way to put some scientific fact.

For instance, he defined a virus as “a piece of bad news wrapped up in protein.” That phrase describes exactly what a virus is. A proteinaceous capsule containing genetic information (in the form of RNA or DNA) that, when disease-causing, is clearly bad news for those infected. As a definition, it is more memorable than any to be found in any textbook. If called upon to describe a virus, it can readily be translated back into drier (more academically acceptable) scientific terms. (Perhaps only "bad news in a protein coat" can be said to be more concise.)

In the introduction to the final posthumous collection of his essays, their editor, David Pyke, predicted that his work would continue to be read for years to come. That prediction has not come to fruition. Only a few of his books appear to be still in print. One must search for second-hand copies of most of his work. This is pity. His writing is deserving of greater attention. Even if the content is sometimes a little dated, the style and expression of ideas merit consideration.

Interestingly, Medawar never really wrote a book as such. Most of his work published in book form consisted of essays or published lectures. That makes them all the more palatable to scientists. Most scientists deal in facts, pure and simple. As already noted, they are not idle speculators. They don’t want to be encumbered with spurious and unsubstantiated speculation expounded at length. Medawar’s essays do not fall into that trap.

I once heard Medawar speak. He gave an invited lecture at the University of Surrey in my final year as an undergraduate there (1980-81). Having been crippled by a series of strokes, he sat in his wheelchair throughout his delivery. His lack of mobility was in stark contrast to what he had to say. His brain had suffered from the strokes, but his mind was lucid and unimpaired. (Somebody once quipped that the effect of the strokes he had suffered was to reduce his IQ to three digits!) As an undergraduate, I had already discovered his writings because my course in Human Biology had the breadth to allow his ideas to be introduced to us. A decade later, I based a master's dissertation on some aspects of the scientific thought expressed in them.