No one likes to admit defeat but early on in my university days – being new to science – I found physiology impossible to grasp and, in desperation, turned to my tutor for advice.
I explained that whereas other subjects formed a meaningful whole, all I got from physiology was an aggregate of disconnected facts.
I could memorise them but that was all – they never really meant anything to me, they just went on forever without coherence.
His answer was to introduce me to the value of analogy – of finding parallels to physiological phenomena in everyday life. For instance, I was familiar with machines, so I should work at seeing the body as a machine.
He suggested I see the heart as a biological pump pushing blood round the body. And the blood itself could be viewed either as a river or a conveyor belt, transporting nutrients to the cells and picking up waste products for disposal elsewhere.
The nervous system, he said, was really a communication network that coordinated the body’s activities. The brain was like a computer, perceiving sensations (inputs) from inside and outside the body, processing them and sending commands (outputs) to ensure health and systemic balance.
Now, whenever I meet with a new process or structure, I routinely ask myself where I have seen something similar before.
Recently, I realised the body is permanently threatened by microscopic invaders. Like an army, it deploys weaponry to defend itself – not bombs or guns but chemical or mechanical devices to deal with hostile bacteria. This has led me into the fascinating world of phagocytes, complement systems, lysozyme, interferon, inflammation and fever.
What was formerly a dull plod has been transformed into a search for useful analogies.
Lesley McHarg is a third-year nursing student in Scotland