Classification of Cranial nerves based on Sensory, Motor and their Functions

There are 12 cranial nerves which supply the head and neck region and have varied functions of purely sensory, purely motor and mixed type. Vagus is the only nerve which supplies to parts other than head and neck region like Lungs, Heart, Intestine and Stomach.

I have divided the Functions of the 12 cranial nerves to make it easy to remember for you. and which is really helpful in National Boards exams and Entrance examinations.

1. Purely Sensory cranial nerves: I, II, VIII
2. Purely Motor cranial nerves: III, IV, VI, VII, XI, XII
3. Mixed Motor and Sensory Nerve Fibers: IX, X
4. Cranial nerves which absorb CSF: I, II, VII, VIII
5. Cranial nerves which originate from medulla: IX, X, XI, XII
6. Cranial nerves which are attached to Pons: V, VI, VII, VIII
7. Smallest cranial nerve: Trochlear nerve
8. Cranial nerve with longest intra cranial course: Trochlear nerve
9. Only cranial nerve which emerges dorsally from the brainstem: Trochlear
10. Longest extra cranial nerve course of cranial nerve: Vagus

Mnemonic to remember Sensory, Motor and Mixed Cranial Nerves: :

“Some say marry money but my brother says big brains matter more”

S: sensory (olfactory nerve – CN I)
S: sensory (optic nerve – CN II)
M: motor (oculomotor nerve – CN III)
M: motor (trochlear nerve – CN IV)
B: both (trigeminal nerve – CN V)
M: motor (abducens nerve – CN VI)
B: both (facial nerve – CN VII)
S: sensory (vestibulocochlear nerve – CN VIII)
B: both (glossopharyngeal nerve CN IX)
B: both (vagus nerve – CN X)
M: motor (spinal accessory nerve – CN XI)
M: motor (hypoglossal nerve – CN XII)
Source: Radiopaedia.org

12 cranial nerves if you are confused with the numbering of the cranial nerves: 

1. Olfactory Nerve
2. Optic Nerve
3. Oculomotor Nerve
4. Trochlear Nerve
5. Trigeminal Nerve
6. Abducent Nerve
7. Facial Nerve
8. Vestibulocochlear Nerve
9. Glossopharyngeal Nerve
10. Vagus Nerve
11. Spinal Accessory Nerve
12. Hypoglossal Nerve

There are Spinal nerves as well which should not be confused with cranial nerves as they arise from the Spinal Cord on both the left and right side which are 31 pairs in number. These 31 Spinal nerves are mixed type supplying to many parts of the body. These are further divided into 5 types Cervical, Thorasic, Lumbar, Saccral and Coccygeal nerves.

1. April 26, 2015

   keti

   7 and 5 are mixed nerves
2. September 10, 2015

   manish

   5,7,9,10 are mixed nerves.

   7 has both SVE and SVA fibers.

   1,2,8 – sensory

   3,4,6,11,12 – mainly motots
3. September 11, 2016

   nagendra maurya

   trigeminal is also a mixed nerve?
4. September 11, 2016

   Varun

   As the ophthalmic (V1, sensory), maxillary (V2, sensory) and mandibular (V3, motor and sensory) branches we can say that the Trigeminal is a mixed nerve.
5. October 13, 2017

   Nuhu

   So helpful
6. May 3, 2018

   kebeyi irene

   what are the functions of each
7. May 8, 2018

   Shahbaz Ali

   Most helpful page then other’s…
8. June 15, 2018

   Tanish

   Yes because it is a nerve
9. June 15, 2018

   Tanish

   So my anus
10. June 15, 2018

    Tanish

    What is nerve