Understanding Cranial Nerves and Their Functions
You have 12 sets of cranial nerves, each responsible for carrying information about a particular type of sensation or movement. What’s the function of each set, and what can you do to keep these nerves healthy? Get answers below.
Cranial Nerve Basics
Cranial nerves — like all nerves — are thin “cables” that transmit electrical impulses throughout the body. These signals help manage everything from intentional movements to autonomic functions like digesting food and breathing.
The cranial nerves originate near the back of the brain, with one on the left side and the other on the right. They are essential in sensory and motor skills and can play a role in both. Some of the sets work in similar or closely related ways.
The 12 pairs of cranial nerves and their functions are:
- Optic nerves. Control vision.
- Oculomotor nerves. Manage eye movement and blinking.
- Facial nerves. Enable facial expression and play a role in the sense of taste.
- Auditory/vestibular nerves. Control sense of hearing and also balance.
- Olfactory nerves. Manage sense of smell.
- Trochlear nerves. Control up-and-down and back-and-forth eye movements.
- Glossopharyngeal nerves. Enable sense of taste and swallowing.
- Vagus nerves. Control heart rate and digestion.
- Hypoglossal nerves. Manage tongue movement.
- Trigeminal nerves. Control facial sensations and jaw movements, also play a role in taste.
- Accessory nerves (sometimes called spinal accessory nerves). Control the movement of neck and shoulder muscles.
- Abducens nerves. Help manage eye movements.
Conditions That Affect the Cranial Nerves
Injuries and several medical conditions can affect cranial nerve functioning, including:
- Traumatic brain injuries from forceful blows to the head
- Strokes that interrupt blood flow in the brain
- Amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease) in which nerve cells break down, causing progressive muscle weakening
- Bell’s palsy that produces muscle weakness and drooping on one side of the face
- Oculomotor palsy and internuclear ophthalmoplegia that affect the movement and positioning of the eyes
- Hemifacial spasms that cause twitching of the muscles on one side of the face
- Trigeminal neuralgia that produces chronic pain in a nerve in the cheek
Cranial Nerve Problems: Symptoms and Treatment
Your doctor can diagnose problems affecting the cranial nerves. But, in general, the cranial nerves may be involved if you experience problems with your vision or hearing, senses of taste or smell, ability to swallow or control facial expressions, or your balance.
Injury or illness can permanently damage cranial nerves. In other cases, they may recover on their own. Some patients also benefit from rehabilitation with assistance from a medical professional such as a physical therapist, audiologist, speech pathologist, or vision therapist.
Caring for Your Cranial Nerves
The best way to support your cranial nerves and their critical functions is to manage your health in general. That includes exercising regularly, achieving and maintaining a healthy weight, eating a healthy diet, not smoking, and managing conditions like high blood pressure and diabetes.
Talk with Your Baptist Health Physician About Cranial Nerve Problems
If you don’t have a Baptist Health physician, you can find one using our online provider directory.