Monday, March 3, 2025

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.

Thursday, February 27, 2025

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.

Wednesday, February 19, 2025

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.

Tuesday, February 11, 2025

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.

Monday, February 3, 2025

Soft Machine

In looking at the human body, sometimes non-scientists have something to offer—if only by the turn of a phrase. While writing the previous post on ‘Water,’ I was reminded that a name that has been applied to the human body is the soft machine. Because of our watery nature we are soft and ‘squashy.’

William Burroughs wrote a book entitled The Soft Machine. It is not an easy book to read, and I have failed to get very far into it on a couple of occasions! However, the title continues to be intriguing.


Monday, January 27, 2025

Water

My idea of considering things that seem blatantly obvious is to highlight how things get overlooked or omitted from consideration. One cannot quite say that the watery nature of the body is something easily overlooked. However, the ‘blatantly obviousness’ of our bodies consisting predominantly of water (60% by all accounts) means that we fail to explore what water is like or how that impinges upon us. What water is like has a direct bearing on how our watery existence manifests itself. Indeed, to raise the question ‘What is water like?’ seems rather odd.

We can all state the freezing and boiling points—although these vary with air pressure and with the purity of the water, etc. But what else can we bring to mind about what water is like? I suggest very little. ‘Wet’ is an obvious response, but what do we mean by wet or wetness?

For example, take a look at the following:
    Water (in general)
    Properties of water

Textbooks of anatomy and physiology talk about the characteristics of atoms and molecules, but rarely do they talk about what is perhaps the most important molecule of all: water. Without it there would be no body chemistry, no physiology, and no anatomy. For a start, water acts as a medium within which biochemistry can take place.

After that, there are so many other characteristics and properties of water that for me to try to list them would be pointless. Not least because I am not a biochemist and their biochemical roles I am not qualified to discuss. What I do want to do is highlight how little the characteristics and properties of water are appreciated when studying physiology. The physiological significance of the nature of water is under-represented in standard textbooks.

A favourite physiology textbook when I was a student was known simply as BDS.’ (This, I understand, came from the initials of the surnames of the original editors.) More precisely, it was Textbook of Physiology and Biochemistry then edited by Bell, Emslie-Smith, and Paterson. It was into its 9th edition when I was a student and appears to have gone through only a couple more editions—with the altered title ‘Textbook of Physiology’—before’ going out of print.

Its 9th edition is the only edition of a physiology textbook I know that had a chapter devoted to water. Indeed, it is the first chapter in that book on a specific topic. The opening chapter, which it immediately follows, is simply entitled ‘Introduction.’ Entitled ‘The Properties of Water,’ that chapter gave water a prominent place, and the student reader is left with the impression that a lot of what followed owed much to what water was like. Thus, water was something of a foundation upon which much depended.

I have been able to trace copies of the final two editions of BDS when there were changes to its editorship. Sadly, neither gives water as prominent a place as in the 9th edition. Instead the consideration of water is subsumed into the more general discussions about bodily fluids, water balance, etc.

In what I have tried to highlight, there is also a nagging question: ‘What would life have been like had the properties of water been slightly different to how they are?’


Sunday, January 19, 2025

Where does anatomy start/stop?

There are many occasions in academic life where a chance conversation may lead to something of lasting value. Coffee breaks are no exception. It was the intention of a former head of a department in which I worked for all available staff to stop for a communal coffee break in the staff room at 11 o’clock each morning. The aim was to allow all staff to mingle and talk. This staff did almost religiously. Indeed, some people were only ever seen at coffee break. A particular reminiscence I have comes from a coffee break in the late 1980s.

I remember overhearing a conversation between two anatomy lecturers. One asked the other where he thought anatomy ended, that is, down to what level of bodily structure one might go before leaving anatomy and entering another discipline. The general conclusion to the discussion was that anatomy ended at the tissue level—beyond this one was entering the realm of cell biology or cytology. Soon after that came molecular biology. Neither of the anatomists gave an argument to substantiate their conclusion. It seemed to be based on a description of structures found at different structural levels. The lack of an argument has stimulated me to mull over the question ever since.

Was it all just a matter of tissue being the lowest level to which our scalpels could take us? The term anatomy, in the traditional sense, does, after all, mean 'cutting up.' Such an argument makes practical sense. Tissues are the last things we can make out with the naked eye. Surprisingly, magnifying glasses are not part of regular dissecting room equipment.

Or was there some other conceptual reason to stop at the tissue level? There are possible avenues along which to proceed. I can raise the question and offer some thoughts, but I don’t expect to be definitive.

The title I am using for this post asks, ‘Where does anatomy start/stop?’ It’s the ‘start/stop’ that should attract attention. It emphasises a direction of travel. ‘Start’ implies that there is the building up from a certain level. ‘Stop’ implies that there is the descent down from some other level above. The question this raises is, ‘What is an anatomist’s direction of travel or approach—top-down or bottom-up?’ Top-down is the direction traditionally adopted for dissection; it is the direction that naturally follows given a body we want to explore and understand. A bottom-up approach is less easy in a practical sense. It is a synthetic approach. To follow it we need to know in advance what is above—we can only get that information from having taken a top-down approach in the first place. Thus, a bottom-up approach is only possible conceptually given prior knowledge.

There is only one book I have ever come across that has taken such an approach. That is Reconstructive Anatomy by Maurice Arnold. Unfortunately, I have yet to find a copy in any of the online libraries offering sight of out-of-print books. Details at Google Books.