A Short Guide to Cranial Nerves
Did you know that we have 37 miles’ worth of nerves in our bodies? These special little cells transmit countless electrical messages that control what we do and how we feel every day.
We can divide our nervous system (or our nerves’ entire entity) into 2 main parts: the central and peripheral nervous systems. The central nervous system entails our brain and spinal cord, while the peripheral deals with nerves outside those regions. Today, we’ll examine the latter.
More specifically, we’ll cover 12 cranial nerves and how they help us live our lives to the fullest. Read on for more!
1. Something Smells Fishy
First, we’ve got the olfactory nerve, or the nerve responsible for smell. Ever heard of starting small, then building up? The olfactory nerve does just that as our shortest cranial nerve.
However, like fish has a distinct odor, it also has a distinct taste. The olfactory nerve accounts for finer levels of taste thanks to its olfactory mucosa.
2. Do You See What I See?
Next up, we have our optic nerve: the nerve responsible for vision. This special nerve belongs to both nervous system regions (peripheral and central).
The optic nerve originates from an optic vesicle that stems from our forebrain. Our optic nerve helps transmit external information from our retina to the visual cortex.
3. Move it
Humans typically like to smell, taste, and see, but they also need to move their eyeballs. Good news, we have a nerve for that, called oculomotor.
It lets us blink our eyes, too (hence, “oculo”). We attribute pupil dilation and constriction to this nerve.
4. Move Some More
Our trochlear nerve gives us more advanced eyeball movement. We can move our eyes in 4 directions with this nerve: up, down, backward, and forward.
This nerve gets its name from a tendon that attaches to the muscle it innervates, the trochlea. We call the innervated muscle the superior oblique.
5. In Your Face
We call our next nerve the trigeminal nerve. This nerve helps with sensations all over your face, jaw, and even part of your taste. It hails as the biggest cranial nerve yet.
The trigeminal nerve has sensory and motor derivatives, thanks to its wide range of functions.
6. More Eye Movement
The abducens nerve allows for more eye movement. This nerve lets you rotate your eyes and move away from their normal resting position.
It lets you look in another direction without turning your head.
More specifically, this nerve controls the extraocular muscle.
7. Quit Making Those Funny Faces
The facial nerve gets you making those funny expressions in response to something wacky. It also has one of the more straightforward names.
It has motor, sensory, and even special sensory functions.
Again, this nerve plays a hand in further refining taste.
8. Hear Me Out
This nerve deals with our hearing and balance. We call it the auditory or vestibular nerve.
The nerve has 2 parts: vestibular and cochlear. Both have different nuclei of origins.
9. A Good Pill to Swallow
Meet the glossopharyngeal nerve. It gives us good taste and lets us swallow our pride.
Thus, it has sensory, special sensory, motor, and parasympathetic action (parasympathetic refers to a further nervous system subdivision). Basically, the nerve activates parts of the tongue, the pharynx, and various glands.
10. That Heartbreaking, Gutwrenching Moment
You guessed it: the vagus nerve deals with heart rate and digestion. It also has special sensory, sensory, motor, and parasympathetic action.
Additionally, it has a connection to your mental health. Click the following page to find out more.
11. Got a Backbone? Then Shoulder the Burden
We call this next one the accessory nerve. It specifically deals with our shoulder and neck muscles.
Hence, it possesses solely somatic action. We divide its actions into spinal and cranial parts.
12. Watch Your Tongue
Last but not least, we’ve got a nerve with purely somatic action. We call it the hypoglossal nerve.
It sits beneath the tongue, as its name suggests. As such, it stimulates tongue movement.
Cranial Nerves Together
Overall, all cranial nerves work together to perform special functions and help us live through our daily lives. They make life as we perceive it possible.
Whether we discuss peripheral 52av nerves, sensory nerves, or motor nerves, they all contribute different, albeit equal, significance in our bodies. So next time you pick up that book, eat an apple, or perform any bodily action, think about all of the nerves involved!
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