“Memorize The Types Of Fibers Of The Cranial Nerves In 10 Minutes So That You Can Write Them Out In Less Than 60 Seconds: A Visuo‐SpaIal Approach With a Long Title” 

by Ethan Beckley 

First memorize a simple mnemonic: 

“Some say marry money, but my brother says big brains maPer more.” 

If you already know this mnemonic and understand how to use it you can skip the next page. 

First memorize a simple mnemonic: 

“Some say marry money, but my brother says big brains maPer more.” 

Here’s how you use the mnemonic: 

There are twelve words of the sentence which each correspond to one of the twelve cranial nerve pairs. 

The first lePer of each word tells you whether the nerve associated with that word conveys sensory informaIon, motor informaIon, or both sensory and motor informaIon. 

Nerve Mnemonic word Type of information

01 - Olfactory Some Sensory

02 - Optic Say Sensory

03 - Oculomotor Marry Motor

04 - Trochlear Money Motor

05 - Trigeminal But Both

06 - Abducens My Motor

07 - Facial Brother Both

08 - Vestibulochochlear Says Sensory

09 - Glossopharyngeal Big Both

10 - Vagus Brains Both

11 - Accessory Matter Motor

12 - Hypoglossal More Motor

The next task is to re‐order the nerves according to their funcIon. Say the mnemonic to yourself while separaIng the the nerves into different groups based on their funcIons. Here’s a Ime‐lapse of what your paper should look like as you separate the nerves into funcIonal groups: 

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

1 2 8

3 4 6 11 12

5 7 9 10

Some

say

marry

money

but

my

brother

says

big

brains

matter

more

You should now have numbers 1‐12 arranged non‐consecuIvely on your piece of paper in groups. It should look something like this: 

The next job is to turn this list into a table. 

1 2 8

3 4 6 11 12

5 7 9 10

Write out column headings for your table. Put the sensory group before the motor group (“look before you leap”). 

The sensory set is: Special Sensory, SomaIc Sensory, Visceral Sensory. 

The motor set is: Branchial Motor, SomaIc Motor, Visceral Motor. 

(Your table does not need all of these lines. Do what works for you.) 

Group Nerve Special"Sensory

Somatic Sensory

Visceral Sensory

Branchial Motor

Somatic Motor

Visceral Motor

Sensory 1

2

8

Motor 3

4

6

11

12

Both 5

7

9

10

The last task is to be able to fill in the table visually. Here I have shaded the boxes to indicate which fibers are found in which nerves. 

The trick is to memorize the image itself, not what the image tells you. 

Learn what the table looks like. It looks like the table below! Learn the paPern and shape of the shading. 

Once you know what the table looks like you should be able to recreate it from memory. 

Group Nerve Special"Sensory

Somatic Sensory

Visceral Sensory

Branchial Motor

Somatic Motor

Visceral Motor

Sensory 1

2

8

Motor 3

4

6

11

12

Both 5

7

9

10

But when you go to recall the informaIon you don’t need to make quite such a fancy table. Here is the same informaIon in a form that you can write out in literally 60 seconds (with pracIce) and have all the data you need. 

Sp S! Som S! Vis S! Br M! Som M! Vis M!

1! ✓ 2! ✓ 8! ✓

3! ✓ ✓ 4! ✓ 6! ✓ 11! ✓ 12! ✓

5! ✓ ✓ 7! ✓ ✓ ✓ ✓ 9! ✓ ✓ ✓ ✓ ✓ 10! ✓ ✓ ✓ ✓ ✓

To summarize the steps: 

Write out numbers 1‐12 in three groups according to the funcIons of nerves 1‐12 (use the mnemonic). 

Write out column headings le_ to right: Sensory (special, somaIc, and visceral) then motor (branchial, somaIc, and visceral). 

Fill out the table with check boxes based on your mental image of how the table should look: 

•  Three check marks on the le_ side of the sensory group •  A flipped “L” shape on the right side of the motor group •  A trickier up/down paPern (3‐4‐2‐4‐0‐3) in the “both” group 

That concludes the memorizaIon method, but here are some bonus observaIons that might interest you. 

Sp S Som S Vis S Br M Som M Vis M

1 ✓ Using a spatial representation of the information it quickly becomes obvious that the cranial nerves that are sensory-only all use special sensory fibers exclusively. They don’t muck around with somatic or

visceral sensory fibers. 2 ✓

8 ✓

3 ✓ ✓

4 ✓

6 ✓

11 ✓

12 ✓

5 ✓ ✓

7 ✓ ✓ ✓ ✓

9 ✓ ✓ ✓ ✓ ✓

10 ✓ ✓ ✓ ✓ ✓

Sp S Som S Vis S Br M Som M Vis M

1 ✓

2 ✓

8 ✓

3 It also becomes clear that motor-only neurons tend to use somatic (voluntary) motor fibers as their

exclusive fiber type.

The only exception is cranial nerve 3, the oculomotor nerve. Since pupil dilation is not under voluntary

control, we can surmise that pupil dilation is controlled by cranial nerve 3.

✓ ✓

4 ✓

6 ✓

11 ✓

12 ✓

5 ✓ ✓

7 ✓ ✓ ✓ ✓

9 ✓ ✓ ✓ ✓ ✓

10 ✓ ✓ ✓ ✓ ✓

Sp S Som S Vis S Br M Som M Vis M

1 ✓

2 ✓

8 ✓

The only lesson that I have learned from inspecting the “both” section is related to CN 5.

The trigeminal nerve goes all over the face. Yet the table reveals that it does not have special or visceral

sensory functions, nor does it have visceral motor functions. From these findings we can conclude that

despite its ubiquity around the mouth, it does not provide taste sensation (Sp S), tongue movement

(Som M), or salivation (Vis M).

3 ✓ ✓

4 ✓

6 ✓

11 ✓

12 ✓

5 ✓ ✓

7 ✓ ✓ ✓ ✓

9 ✓ ✓ ✓ ✓ ✓

10 ✓ ✓ ✓ ✓ ✓