Anatomy has a lot in common with geography. The phrase ‘topographical anatomy’ is sometimes used to refer to the study of the location of different body structures. Whether ‘study’ is the correct word is a moot point. Learning where everything is situated is not so much ‘study’ as ‘memorisation’. A lot of anatomical study involves rote learning. This is onerous, tedious, and [add your own derogatory term(s) here if you find this process irksome]. It is not learning in the true sense. It is 'cramming' for an exam.
Aides to learning (and memorising) are to be welcomed. There are many mnemonics one may use. (Some of them are clean! The clean mnemonic for the 12 pairs of cranial nerves I do not remember, but the more risqué one I had memorised on only the second hearing!)
There is a more thoughtful approach. Where possible, look for anatomical principles. Look out for commonalities and patterns.
The first of these is ‘the rule of three’. Anatomical structures do not consist of a single cell type. They are typically made of layers of cells and extracellular material. These layers are often continuous with each other and are hard to differentiate. Sharp distinctions between layers are not always obvious. However, that has not stopped anatomists from giving them specific names.
As a rule of thumb, start with the assumption that there are three named layers. Look out for these and memorise them that way. What applies to one structure often applies to another. Once a principle has been learned, it is applicable elsewhere. Sometimes the same or a similar word is used.
Helpfully, the outermost layer of a structure is usually a connective tissue capsule that envelops an organ or loose connective tissue that forms a kind of ‘packing’ (such as around blood vessels). If there should be more than three named layers, it is often because a ‘parent’ layer has been subdivided. Usually, this is the middle or inner layer. Realising this helps.
A question arises.
Is the ‘rule of three’ a genuine anatomical arrangement, or is it a reflection of the mentality of the anatomists who originally named these layers? That is something else to consider. Being unconvinced about what we have to learn helps us remember it!
Newton saw seven colours in the rainbow. (From which we get the mnemonic Richard Of York Gave Battle In Vain.) But the seven-colour idea was more in keeping with a Renaissance tradition than observation. Did he really see seven colours? And do we when we see a rainbow or light shone through a prism? Or are we simply following what we have been taught?
