12 Cranial Nerves

The brain is the important center of our body that controls all the other organs, functions as well as sensations. There are many nerves arising from the brain and reaching various parts of the body. There are 12 cranial nerves that carry out the most important functions in the human body systems. We shall learn all about the 12 cranial nerves and their functions in the following paragraphs.

The 12 Cranial Nerves and their Functions

As we all know there are 12 cranial nerves of the body. These nerves are important as most of them involve the interpretation of the five senses of our body. Some of these also help in controlling the muscles and glands. Let us go into the details of the 12 cranial nerves and their functions. You will find that each of the specific cranial nerves names are represented with a Roman numeral.

Olfactory Nerve I
The olfactory nerve I is a fully sensory nerve that originates in the telencephalon, the largest division of the human brain. These nerves have anterior olfactory nucleus. The functions of this cranial nerve include sense of smell. This nerve reaches the cerebral cortex, however, it does not enter the thalamus like the other cranial nerves.

Optic Nerve II
The optic nerve II is also a fully sensory nerve. It originates from the diencephalon region of the brain and includes the ganglion cells of the retina. The functions of this nerve include sense of light. They help one see and if these nerves are damaged, it leads to temporary or permanent blindness.

Oculomotor Nerve III
This is also a fully sensory nerve that originates from the midbrain. These nerves help in controlling the pupil constriction and eye movements. It helps the eyes respond to external stimuli and accordingly constrict or dilate the pupils as and when the light conditions change.

Trochlear Nerve IV
The trochlear nerve is a mostly a motor nerve that originates from the trochlear nucleus. This nerve has an important function in the movement of the eyeball. It helps one look down and look towards a midline object.

Trigeminal Nerve V
The trigeminal nerve functions both as a sensory as well as a motor nerve. It originates from the pons and has a role in controlling the muscles of the face. This nerves helps in chewing, provides sensation of pain and touch to the face as well as head region.

Abducens Nerve VI
This motor nerve originates from the posterior margin of Pons. This nerve helps in movement of the eye to move away from the midline of the face. It works in association with cranial nerves III and IV. This helps one see normally. If there is any difference in the function of these nerves, one tends to have double vision.

Facial Nerve VII
The facial nerve VII has both sensory as well as motor functions. It originates from the Pons just above the olive. This nerve helps provide the facial muscles the ability to smile, frown and form other facial expressions. This nerve also helps two third region of the tongue to develop taste. The facial nerve also provides the sensation of touch and pain to the ear.

Vestibulocochlear Nerve VIII
This is a sensory nerve that has a role in the sense of sound. It also helps in maintain balance (gravity) and movement of the body. This means it plays a role in the acoustic and vestibular functions.

Glossopharyngeal Nerve IX
The glossphrayngeal nerve IX has sensory and motor functions and arises from the medulla. It helps one develop taste in the back of the tongue. It also provides the sense of touch as well as pain on the tongue and tonsils. This nerve also has a role in controlling the muscles of the mouth during swallowing.

Vagus Nerve X
The vagus nerve also works as a sensory and motor nerve. It has one of the most important functions in the human body. This cranial nerve helps in controlling the sensory as well as motor functions of the heart and glands. This nerve also has a role in digestion.

Cranial Accessory Nerve XI
The cranial accessory nerve XI is a motor nerve. It is also called spinal accessory nerve or accessory nerve. This nerve helps in controlling the trapezius muscle and the sternocleidomastoid muscle that are involved with the movements of the head.

Hypoglossal Nerve XII
The hypoglossal nerve XII is the 12th cranial nerve that is a motor nerve. This nerve helps in the proper movement of the tongue.

12 Cranial Nerves and Acronyms

Are you finding it difficult to memorize the 12 cranial nerves and their functions? Then you should probably try memorizing the 12 cranial nerves acronyms. They will help you remember the functions as well as names of these cranial nerves. Let's have a look at the 12 cranial nerves mnemonics.

12 Cranial Nerves Acronym	Names of Cranial Nerves	12 Cranial Nerves Mnemonics	Cranial Nerves Functions
OLd	Olfactory	SOME	Smell
OPie	Optic	SAY	Vision (retinal)
OCcasionally	Oculomotor	MARRY	Pupil constriction and eye movement
TRies	Trochlear	MONEY	Eye movement
TRIGonometry	Trigeminal	BUT	Mastication and face sensation
And	Abducens	MY	Eye movement
Feels	Facial	BROTHER	Face muscles control, 2/3 taste on tongue
VEry	Vestibulocochlear nerve	SAYS	Hearing
GLOomy	Glossal-pharyngeal	BIG	Gag sense and swallowing
VAGUe	Vagus	BRAINS	Parasympathetic functions, coughing
And	Spinal accessory	MATTER	Shrugging shoulders
HYPOactive	Hypopharyngeal	MOST	Tongue protrusion

This is some information about the 12 cranial nerves, their functions and mnemonics. These nerves are very important part of the nervous system that helps one respond to the 5 senses. Any damage to these nerves can lead to loss of senses like hearing, vision, sense of touch, etc. Hope, you have found the above information is helpful for you.