Sunday, July 27, 2025

From 'Adventures in Human Being'

In Gavin Francis’ book Adventures in Human Being, the author mentions the novel Zeno’s Conscience by the German-Italian writer Italo Svevo (1861-1928). In that novel, the main character, a hypochondriac businessman called Zeno, meets an old school friend. This friend is suffering from severe arthritis. Discussion moves to how, when walking briskly, each step might take less than a second and yet involve the action of no fewer than fifty-four muscles. Zeno finds this rather shocking and turns his attention inward, hoping to sense each one of those muscles in action. This does him little good. It does not give him a greater understanding of his body or sense of his being. In fact, it becomes counterproductive as walking becomes more difficult for him.

The story recognises how, in order to perform certain complex actions, it is not necessary for us to be consciously aware of every muscle contraction we make. Nor, for that matter, every muscle relaxation made. Most of our movements are done without careful thought or consideration. As I have typed this, I have been thinking about a number of different things, none of them being about which finger to put on what key or the order in which those actions must take place. (Witness the many typos I always need to correct.) Chameleons, an old professor once suggested, have their distinctive way of moving because, lacking a highly developed cerebellum, they need to move more deliberately. The cerebellum stores the information – some might call this a set of programmes – for all the movements we make. When we need to make a movement, we do not have to think much about it. We decide to move and subconsciously call upon the cerebellum’s involvement. In effect, the programme held there is run, and the movement is results.

What would it be like to be a chameleon? If my old professor was correct, it is doubtful whether I could think and type at the same time. I would have to think more carefully about every finger movement. This would surely detract from what I am thinking about. (It’s a good job I don’t chew gum!)

We tend to think of movement primarily in terms of muscle contraction. However, to make a movement, a whole repertoire of relaxations as well as contractions must take place in a highly coordinated way. A contraction may even be isometric in that it may occur without a change in length taking place. By becoming taut, that muscle provides a stabilising effect. There is much more to walking than Zeno was told, which is perhaps lucky for him.


Saturday, July 19, 2025

Being smarter than 'phones

Biological knowledge must include understanding; it must be more than can be called up on a smartphone.


This note I made before the advent of AI. I am a great fan of AI. It can help us understand biology, especially if the responses given prompt us to ask better questions (aka prompts*).

* I wonder if, at least in some people's minds, the word 'question' will come to be replaced by the word 'prompt'.


Friday, July 11, 2025

Anatomical Junctions

The previous post had little, if anything, to do with the human body and more to do with South London's railways. So, here is a post about genuinely named anatomical junctions. I provide it by way of compensation and recompense for the previous post.

The following is a list of terms containing the word 'junction.' I have limited it to structures larger than cell size and provided a brief description for each:

  • Atrioventricular Junction: The junction between the atria and ventricles of the heart, where the heart valves and conducting system are located.
  • Costochondral Junction: The junction between the ribs and their costal cartilage, which allows for flexibility in the rib cage.
  • Myotendinous Junction: The junction between a muscle and its tendon, where the force of muscle contraction is transmitted.
  • Neurovascular Junction: The junction between nerves and blood vessels, often referring to points where nerves and vessels run close together.
  • Oesophagogastric Junction: The junction between the oesophagus and the stomach, where the lining of the digestive tract changes.
  • Rectosigmoid Junction: The junction between the rectum and the sigmoid colon, a transition point in the large intestine.
  • Sacrococcygeal Junction: The junction between the sacrum and the coccyx, a slightly movable joint.
  • Sternoclavicular Junction: The junction between the sternum (breastbone) and the clavicle (collarbone), a key joint for shoulder movement.
  • Vesicourethral Junction: The junction between the bladder and the urethra, controlling the flow of urine.

I cannot vouch for how exhaustive this list may be. My online searches (including the use of AI) yielded just these. I do not remember the term 'junction' being used frequently. Indeed, only a few of those above (such as the costochondral junction and the rectosigmoid junction) were ever commonplace. Rather, the sacrococcygeal junction was more often referred to as the sacrococcygeal joint and the sternoclavicular junction as the sternoclavicular joint.

At every meeting of two veins, there is a junction. (Following the direction of blood flow, veins DO NOT branch.) Where named, a venous junction seems to reflect a need for clinical rather than anatomical precision. I was never taught a litany on named venous junctions.


Thursday, July 3, 2025

Eponyms 2 - Poupart's Junction

I seem to be starting each month with something about eponyms. At least this time it gets a new number. That is because it is quite different from what has gone before when it comes to eponyms and to anything else for that matter.

Poupart’s ligament is not the only eponymous use of the name. Upon reading Richard Gordon’s Doctor in Love (1957) recently, I found this amusing story.

During a viva voce examination, Gordon is asked

“You are familiar with Poupart’s ligament?” asked the Professor, as we got on to hernias.
Of course, sir.”
“Ah! But where is Poupart’s junction?”
For a second I felt panic. This was an anatomical feature I’d never heard of.
“It’s the next station to Clapham Junction,” [the professor] said with a chuckle.

This geographical detail is indeed true—see the map below. However, I cannot vouch for the veracity of the rest of Doctor in Love (including whether this viva voce examination ever did take place).


FYI Poupart’s Junction is not named after the Poupart discussed in a previous post. It is named instead after the market gardener Samuel Poupart (b. 1807), who once owned a farm on land that is now part of the nearby Shaftesbury Park Estate. In particular, see the section on its history. (And if you really want to know more go here.)

[Source - https://upload.wikimedia.org/wikipedia/commons/1/1d/Clapham_Junction%2C_Stewarts_Lane%2C_Lavender_Hill_%26_Longhedge_RJD_17.jpg ]

POUPART’S JN.’ is written at an oblique angle, immediately to the left of the ‘LONGHEDGE’ that appears towards the middle of the map.