- 07 Jan 2022
- Medical Revision
Learn how to help simplify your revision with 4 types of mnemonics, the learning technique which helps improve and assist the memory.
Which nerve roots innervate the diaphragm?
When over 20 doctors who had been out of medical school for several years were recently asked this question, they ALL remembered that the nerve roots in question were C3,4,5. Not only that, but the reason they stated for being able to remember this fact was that they had all learnt a mnemonic at medical school, ‘3,4,5 keeps the diaphragm alive’. A good point at which to start when trying to illustrate the usefulness of mnemonics.
In medicine, mnemonics have long been popular especially in subjects such as anatomy and subjects which seem to be based on memorising lots of information in a short space of time for effective regurgitation.
A mnemonic is essentially a ‘tool’ or device which helps with the retention of information.
The device for remembering the innervation of the diaphragm as illustrated above is one such mnemonic which incorporates the information into a brief and memorable rhyme.
We have classified them into 4 varieties, and for ease of memorisation have called them types 1, 2, 3 and 4.
This is the acronym, and one of the most common types of mnemonic. For example, if a baby goes blue on the ventilator, neonatologists remember the word DOPE. This acronym consists of four letters, each of which stands for a possible cause for the baby to go blue.
D Displacement of the tube
E Equipment failure
This is quite easy to remember and highly useful at 4am when dragged half asleep onto a neonatal intensive care unit, and when confronted with the situation in the more artificial circumstances of an exam paper.
Now obviously these aren’t the ONLY causes, but they are the main causes. The idea with mnemonics as we shall reiterate is to keep them simple.
Other variations of this theme are seen. Some mnemonics don’t spell out a word, but instead make use of some other combination of letters which are easy to remember or make use of sequences of memorable numbers, such as the vowels, AEIOU.
Each letter has been used to represent one of the causes of coma.
Apoplexy, Epilepsy, Infection, Oxygen, Urea.
As you can see writing mnemonics takes a bit of imagination and remembering them requires you to understand that use is made of ‘proxies’, in other words a word like urea represents generic ‘metabolic conditions’ rather than urea itself being a cause of coma. This above mnemonic also demonstrates to us that a lot of mnemonics use a broad brush when thinking of differentials. The use of mnemonics is to give you a hook to ‘hang your coat’ or differentials on, not to help you remember all 35 causes of a coma.
Never Eat Shredded Wheat
– the four points of a compass and their order, i.e. North East South West.
Okay so there you have it, the one we all learnt as a schoolchild, and if you are not familiar with that one then maybe you remember the medical one about ‘ten zombies b*gger*ng your cat?’ A picturesque though unfeline way to remember the branches of the facial nerve. Here each word, or rather the first letter (or so) stands for another surrogate word. Never for North, eat for East, etc etc.
‘Thirty days hath September’
This requires a bit more imagination to construct and needs to be extremely memorable and easy to remember, and hence is not seen that often; when done well however it can’t be beaten as an aid and sticks in the mind for many years.
Type 4 is the hybrid of the above types.
Its usefulness arises because it is all very well constructing a mnemonic such as DOPE for the causes of the blue ventilated baby, except that it does leave you with the problem of how you are going to associate the word DOPE with the concept of the blue baby. In other words, how will you remember what the mnemonic DOPE is for? Is it for the causes of renal failure or the causes of cough?
The way this is overcome is by knitting one mnemonic inside another.
Thus: ‘A baby blue has got no hope if you forget to think of DOPE.’
Okay, now we know that DOPE is associated with the baby who goes blue on the ventilator. Thus, this combination of types 1 and 4 should be easier to remember than the word DOPE on its own.
How to write mnemonics
The above categorisation enables you to think about mnemonics when you encounter them and helps you to devise your own.
A lot of people have thought long and hard about mnemonics over the years and have concluded that the best mnemonics are usually those which are:
Relevant to you
All the above!
Often the most effective mnemonics are those you devise yourself.
Don’t worry if you are stuck for inspiration, we have you covered. You can find examples of our medical mnemonics every Monday on our Instagram, Facebook and Twitter accounts. Be sure to follow us so you don’t miss out!
- 07 Jan 2022
- Medical Revision