Perdurantism and endurantism are opposing philosophical views about the nature of persistence and change. I mention them here because they may be applied to the nature of ourselves as physical objects—as organisms. As organisms, we have mental and physical aspects that both require philosophical and scientific examination. We possess an individuality or selfhood that seems to persist over a long period of time, irrespective of most of the physical changes we incur, and yet that selfhood can change markedly should only the brain be affected in some way. Even then, our social identity remains unaltered. Both perdurantism and endurantism offer potentially thought-provoking insights useful in interrogating what we are. (So I have no difficulty borrowing them from philosophy.)

According to perdurantism, objects have distinct temporal components that allow them to endure over time. This could be compared to a movie that is made up of several separate frames. Perdurantism holds that an object is never fully present at any given time. Rather, it lives as a sequence of temporal segments (like movie frames) that are played out over time.

In contrast, endurantism suggests that things are fully present throughout something’s entire existence. Over time, that thing’s identities do not change. Unlike the movie metaphor mentioned above, endurantism is more akin to how something is captured in a snapshot or how something is given a once-and-for-all label. According to endurantism, a thing remains unchanged during its whole existence.

Even from this extremely brief description, one can see how an embodied human being can be viewed from both perdurantist and endurantist perspectives. This raises questions about how one thing (or type of thing) can be understood from two opposing perspectives simultaneously.

NB, Not all the questions I raise are necessarily cast iron or foolproof. There may be weaknesses here, although I can’t put my finder on them at the moment.

Good at Anatomy

Having worked in anatomy, one question I never asked - and never heard asked - was what made somebody ‘good’ at anatomy. Indeed, what does ‘Good at anatomy?’ actually mean?

Most students were engaged in rote learning the names of parts, their relation to other parts, connections, divisions, etc. Our best students were those who could remember the most. Learning anatomy was tantamount to memorising a gazetteer of place names. A London taxi driver doing ‘the knowledge’ probably learns more places and locations and routes between them than does any medical student learning parts of the human body. For good reason, this type of anatomy is called ‘topographical anatomy,’ for it is about learning where things are - and their names. Would one say that a taxi driver is good at geography - or, more specifically, the geography of London? Is there something more to being an anatomist - or a geographer? Perhaps if I were to find out what makes for a good geographer, that might inform what I consider to be a good anatomist?

We must also remember that the parts of the body did not come ready named. We named them, and those names should never be assumed to be set in concrete. The conventions regarding anatomical nomenclature have changed from time to time… and been revised… and reviewed etc.

So for somebody to be good at anatomy, there must be something more than simply being able to remember names. I once had a colleague who learned anatomy in France. At that time - the 1970s or 80s - he had to learn the name of each part in three languages: French, English and Latin. And yet, I am not entirely sure whether he saw himself as an anatomist per se. His real academic interest was in studying the early developmental fate of cells, which he had marked with fluorescent viral markers.

Is there a frame of mind that makes an anatomist? A famous anatomist from the nineteenth century, Sir Ashley Paston Cooper (1768-1841), once commented that he considered a day to have been wasted if he had not dissected something. So perhaps it is the desire to dismantle that marks out the anatomist?

And that, interestingly, returns us to the Humpty Dumpty problem. Cooper’s days felt wasted if a dissection had not been performed. It does not appear to have occurred to him, whether not putting things back together again was not also a waste.

Anomalous lobes in the lungs

As part of an anatomy course, a group of four medical students had been dissecting the thorax of a cadaver. It had taken them a few weeks as they progressed step-by-step from the skin to a now almost empty chest cavity. The heart remained in place for the next phase of dissection but the lungs were not removed.

Upon completion of this stage in the process, the students were required to be assessed by a demonstrator who would check on their learning. The demonstrator for that group of students was me. I was duly called over to quiz them. What met me was an open, lung-less cavity with the anterior wall of the chest folded back. The lungs lay elsewhere on the dissecting table.

'Before we start,' I said, 'let's put everything back into its original place so we can go through what you've done step by step.' The students picked up the lungs, quickly looked at them and squeezed them into their respective cavities. Or so they thought.

The left and right lungs are not exact mirror images of each other. For a start, the heart is situated slightly to the left and so impinges upon the left lung. For this reason - or so it is usually stated - the left lung has just two lobes, whereas the right has three. (Whether that is the complete explanation, I do not know. Indeed, what follows may suggest that the explanation lies elsewhere.)

What the students did, before putting the lungs back into the chest, was count the number of lobes: two means left, three means right. The lungs being the spongy compliant organs could be squeezed in fairly easily. But then, lungs can be squeezed into almost any space - even those from embalmed cadavers.

With this body, I could tell, things were not as expected. The left lung had three lobes (not two); the right lung had two lobes (not three). The opposite of what the students had expected; the opposite of what they had been taught and what they had read. By simply counting the lobes the students had proceeded to squeeze each lung, into a cavity of the wrong shape and size - and facing backwards!

There are more accurate ways of determining to which side a lung belongs. These do not require the number of lobes to be counted. There are a number of clearly visible surface characteristics which allows the lung to be orientated in space.

I pointed out the error to the students and passed it off lightly. We were able to laugh about it and started again. The students passed the quiz. They were serious-minded people who had applied themselves diligently to their task. I am sure that their error was a useful learning experience. However, it was actually quite a grave mistake. It would even have resulted in failure under stricter conditions.

Significantly, this was the first time any of those students had realised this anomaly about their cadaver. None of them had noticed when the lungs were first removed that the number of lobes was atypical. How could they have missed something so glaringly obvious?

Being diligent students may have been their problem. They had followed the dissecting instructions meticulously. They had removed the lungs and put them aside for dissection later as instructed. They had proceeded to dissect the empty cavities left behind before focusing on the lungs as separate organs. When it came to examining the lungs, there was, as described one with two and one with three lobes. They had assumed - as stated above - two means left, three means right.

Were the students really at fault? They were following instructions; they were doing what they were required to do. They were not required to explore the human body or discover things about it for themselves. They were put into an environment in which instructions were to be followed. It may be little wonder that they slipped up. They were learning the contents of a prescribed syllabus. The cadaver they used was a means of simply backing this up when a spirit of discovery might have been preferable.

Up to date textbooks

As students go off to college or university - some for the first time - they should take heed! Students need to be wary of the latest editions of textbooks - especially given how much textbooks cost. Students should always ask whether 'latest edition' means the same as 'up to date'. The assumption is that this is the case - but this assumption is wrong! Students often feel obliged to buy the latest edition of a textbook lest they miss out on some vital bit of information missing from an older ‘out of date’ edition. But is passing or failing ever down to just one bit of information present or absent from a textbook? 

Some textbooks recommended for the courses with which I have been associated have gone through new editions three or four times in as many years! No academic discipline can claim to have been revised or updated that often - let alone in such a brief space of time.

Textbooks may change rapidly but academic disciplines change very slowing - and some seem to change rarely. Some fundamental details never change. What does change is a textbook’s layout and presentation; how publishers what it to look. Headings (and typesettings) may change; diagrams and tables may be added, removed or modified; page numbers may change accordingly. None of this reflects a major change in learning or fundamental course content. If any ‘major’ intellectual development did occur between editions it would be big news. Lecturers would certainly know about it and change their teaching material to suit. They would even emphasise the fact. (What lecturer would not want to be seen discoursing authoritatively on the latest big discovery?)

So beware before you spend. Ask yourself, Why do academic libraries keep old editions of books if they are always so flawed? Why are previous editions of a textbook not all pulped the moment a new edition appears? Why are they sometimes donated to poorer, third countries? When we ask questions like these, we see things quite differently.

The Schematic Circulation of the Blood (2)

Here is another diagram showing the circulation of the blood. I have a number of these to show. What I want to do is show how different one of the most commonly used illustrations found in textbooks of anatomy and physiology can be. Other than that, I am making no other judgements about the quality of those diagrams. (Accordingly, I am not giving bibliographic details or otherwise indicating their source.)

To see other diagrams in this series, click the label 'The Circulation' below or in the margin to the right.

Some diagrams may be better viewed downloaded.

A headache when passing water

A radiologist once told me what at first sight seemed to be a very strange story. It was about a man who went to see his GP because every time that he emptied his bladder he got a terrible headache. There is no medical condition that presents in this way and so the GP was rather puzzled. As was I. There is no obvious 'cause-and-effect' type pathological process that could explain what was going on. The man was duly sent for tests at the local hospital.

In brief, what they found was not one but two pathological processes operating at the same time. Firstly, the man had a condition called hydronephrosis. This literally means a 'water-logged kidney'. This causes the kidney to become swollen with the urine it produces. This swelling can be relieved by passing that urine. However, hydronephrosis is a well-known condition and headaches when passing urine is not one of them. So, to explain the man’s headaches, there must be more.

Upon further examination, it was found that the man also had a tumour of one of his adrenal glands. (There are two - one situated above each kidney, hence the name.) This tumour was of an adrenaline producing variety. Again, these are quite well known and the man's symptoms were, again, not fully explained.

When both diagnoses were put together the picture became clear. The adrenal tumour was of the adrenal gland that sat upon the water-logged kidney. When that kidney was swollen, it pressed on the adrenal gland and its tumour squeezing it against the diaphragm and posterior abdominal wall. This impeded the venous drainage of the adrenal gland. Thus, a reservoir of adrenaline produced by the tumour built up inside the gland. When, upon urination, the swelling of the kidney was alleviated, so too was the squeezing of the adrenal gland. Thus, a big rush of adrenaline was released. That immediately sent the man's blood pressure rocketing giving him his post-urination headache.

Even though a clear chain of events could ultimately be determined, this is not a simple story of cause-and-effect. The urinary system is involved, as is the endocrine system (since that system includes the adrenal gland). So too is the cardiovascular system. It was the pressure in that system that rose upon the release of the stored-up adrenaline. Then again, the nervous system was also involved. It was there that the headache was both generated and experienced. It came about due to the pressure in the arteries within the brain. Then there would have been the other effects of a large dose of adrenaline elsewhere in the man's body which were not immediately obvious.

This, then is really a story about what happened to a whole organism - and to a person. It is not simply a clinical case study about pathophysiological details but an example of the integrated nature of ourselves as organisms. Indeed, all case studies are ultimately really stories about persons.

Reconstruction

I previously described how I originally considered calling this blog, ‘Deconstructing Humpty’ and often think in terms of ‘Reconstructing Humpty’. This naturally raises the question of what these phrases imply. I have discussed deconstruction. What does the phrase ‘Reconstructing Humpty’ mean?

I am sure that it can mean different things to different people. Not all of these have been explored fully by me. There may also be meanings of which I am unaware. However, one meaning important to me is that of a ‘re-imagining’. It means developing a new mental image or impression of what we are dealing with - the human body as seen from a primarily scientific perspective.

Furthermore, I suggest that Reconstructing Humpty implies a ‘re-construing’.  When learning Latin at school, children were often given a passage of text and told to ‘construe’. Put simply this means ‘translate’. However, merely swapping Latin words for English is not enough. One must also ‘interpret’. That is, one must convey the meaning that was intended by the writer of the passage in question. This means using the most appropriate words in the best possible way.

Thus the idea of ‘construction’ is not out of place here. An interpretation is a reconstruction - in a different language - of something previously constructed in another. To construe things about the human body is to interpret what we find. As part of this, we must ask whether we currently have the best or most accurate interpretation of what the body is like.