AnnaMarie Houlis
Your body has several hundred nerves and billions of nerve cells. However, only 12 of them extend from your brain (instead of your spinal cord), including your cranial nerves.
All of the nerves in your body are basically bundles of tissue that are built out of neuron cells. They send information to and from your brain and spinal cord. So they tell your muscles to move, for example.
Your nerves also turn stimulus information into senses so you can see, hear, smell, taste and touch different things in your environment.
Your cranial nerves are also responsible for some of your body’s most important functions.
Here’s a bit of background on what cranial nerves do and the different types.
What Are Cranial Nerves?
Cranial nerves are pairs of nerves that extend directly from your brain. Each nerve controls muscles or collects sensory information from the neck, neck or upper body. One nerve (the vagus nerve) extends further, helping control your heart rate, digestion and immune system.
Without your cranial nerves, you wouldn’t be able to blink, swallow, taste or hear. You wouldn’t get that annoying twitch in your cheek that won’t go away. Perhaps most importantly, your body wouldn’t be able to maintain a steady heartbeat to keep your blood pumping.
How Many Cranial Nerves Do You Have
Your body has 12 pairs of cranial nerves in total (one extending from each side of your brain).
Broadly speaking, you can divide your cranial nerves into three camps:
- Sensory nerves that help you feel, hear, see, smell or taste
- Motor nerves that help control your muscles and glands
- Nerves that do both
Each nerve is assigned a specific number from one to 12 that designates where it exits from the skull. That makes it easier to remember the nerves in order—and to use cranial nerve mnemonics, as you’ll discover below.
12 Types of Cranial Nerves
Here are the 12 types of cranial nerves.
- Olfactory Nerve – sense of smell (sensory nerve)
- Optic Nerve – sense of sight (sensory nerve)
- Oculomotor Nerve – ability to move and blink your eyes (motor nerve)
- Trochlear Nerve – ability to move your eyes (motor nerve)
- Trigeminal Nerve (“Dentist Nerve”) – ability to feel sensations in your face, taste and move your jaw (sensory and motor nerve)
- Abducens Nerve – ability to move your eyes (motor nerve)
- Facial Nerve – ability to move your jaw and facial muscles, taste, hear; also connected to your salivary and tear glands (sensory and motor nerve)
- Vestibulocochlear Nerve – sense of hearing and balance (sensory nerve)
- Glossopharyngeal Nerve – ability to taste and swallow (sensory and motor nerve)
- Vagus Nerve – controls digestion, heart rate and other organ and immune system functions (sensory and motor nerve)
- Accessory Nerve (Spinal Accessory Nerve) – ability to move your neck (motor nerve)
- Hypoglossal Nerve – ability to move your tongue (motor nerve)
Mnemonics for Remembering Cranial Nerve Names
A mnemonic is a system or strategy that can help you remember a list or set of facts. Rhymes like “i before e except after c” are perfect examples. Another kind of mnemonic involves taking the first letter of each word in a list and using it to make a new word or sentence.
You can use these kinds of mnemonics to help remember any manner of complex subjects (e.g. amino acids). This includes the order of the cranial nerves, as well as their functions. Several generations of tired med students (and med student professors) have already come up with some:
- On Old Olympus’ Towering Top, A Friendly Viking Grew Vines And Hops
- Ooh, Ooh, Ooh To Touch And Feel Very Good Velvet. Such Heaven!
- Old Oliver Ogg Traveled To Africa For Very Good Vacations And Holidays
- Only Owls Observe Them Traveling And Finding Voldemort Guarding Very Secret Horcruxes
- Old Opie Occasionally Tries Trigonometry And Feels Very Gloomy, Vague And Hypoactive
Because mnemonics are meant to assist in your memory, you may find that one or several of these helps you remember the cranial nerves. But if none of these work for you, you can always build your own.
It’s pretty easy. To start, take the first letter of the cranial nerves:
- O for Olfactory
- O for Optic
- O for Oculomotor
- T for Trochlear
- T for Trigeminal
- A for Abducens
- F for Facial
- V for Vestibulocochlear
- G for Glossopharyngeal
- V for Vagus
- A for Accessory (alternatively, “S” for Spinal Accessory, depending on the mnemonic)
- H for Hypoglossal
Armed with these first letters, you can put together a cranial nerve mnemonic, like so: Old Octopuses Ought To Try Asking For Vipers, Gargoyles, Vacations And Hairpins
Mnemonics for Remembering Cranial Nerve Functions
When you’re learning the cranial nerves, many programs also require you to learn each nerve’s function, too. Since many nerves serve several purposes, remembering exactly what each does with a mnemonic is tricky.
But you can use a mnemonic to remember each nerve’s basic function. You need just three letters:
- S for Sensory – These nerves tell you when you encounter senses like light, sound, smell, tast, or touch.
- M for Motor – These nerves tell your muscles and glands to move, release hormones or take other actions.
- B for Both – These nerves combine the two functions.
With these letters in hand, you can assign a letter to each nerve. Remember that to make these mnemonics work, the nerves have to stay in their proper order from one to 12:
S S M M B M B S B B M M
There are three common mnemonics that students use to remember the cranial nerve functions:
- Some Say Marry Money, But My Brother Says Big Brains Matter Most
- Some Say Money Matters, But My Brother Says Baked Brownies Matter More
- Some Say My Mother Bought My Brother Some Bad Beer, My, My
You can use any of these mnemonics to help you memorize the 12 cranial nerves and their functions. Or, if you find it more helpful, you can make up your own.
But no matter which method you try, the Dorothy memory app can greatly enhance your studying power. The app uses scientifically-backed methods to figure the exact day you’re likely to forget something. Then, it sends you an alert, so you can quickly refresh your memory.
With the power of mnemonics and Dorothy, you’ll have the cranial nerves memorized before you can say “vestibulocochlear” 12 times fast.