Dominic Stone
The hypoglossal nerve, also known as the twelfth cranial nerve, is responsible for innervating the muscles of the tongue. It is a motor nerve that carries signals to and from the brain, controlling muscle movement and enabling functions such as speech, swallowing, and moving substances around in the mouth. The nerve originates in the hypoglossal nucleus, located in the lower part of the brain, and extends through the hypoglossal canal to supply the tongue with the necessary muscle control.
| Characteristics | Values |
|---|---|
| Name | Hypoglossal nerve |
| Other Names | Cranial nerve 12, Twelfth cranial nerve, CN XII |
| Origin | The hypoglossal nucleus in the lowest part of the brain, the medulla |
| Function | Controls the muscles of the tongue, enabling speech, swallowing, and movement of substances in the mouth |
| Controlled Muscles | Genioglossus, Hyoglossus, Styloglossus, Intrinsic muscles, Geniohyoid, Thyrohyoid, Omohyoid, Sternohyoid, Sternothyroid |
| Innervation | Motor innervation of the muscles of the tongue |
| Sensory Nuclei | Reflex links with gustatory and tactile oral stimuli |
| Associated Disorders | ALS, Encephalitis, Head and neck cancer, Sleep apnea, Cranial nerve palsy |
Explore related products
What You'll Learn
- The hypoglossal nerve is a motor nerve that carries signals to and from the brain
- It innervates the genioglossus, hyoglossus, styloglossus, and intrinsic muscles of the tongue
- The nerve originates in the hypoglossal nucleus in the lower part of the medulla
- It is also known as the twelfth cranial nerve, cranial nerve XII, or CN XII
- Disorders of the hypoglossal nerve make it difficult to speak, swallow, and chew food
The hypoglossal nerve is a motor nerve that carries signals to and from the brain
The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a motor nerve that carries signals to and from the brain. It is responsible for innervating the muscles of the tongue, including the genioglossus, hyoglossus, styloglossus, and intrinsic muscles. These muscles enable essential functions such as speaking, swallowing, and moving food around in the mouth.
The hypoglossal nerve originates in the hypoglossal nucleus, located in the lowest part of the brain, specifically in the medulla or medulla oblongata. It emerges as several small rootlets that join to form the nerve. The hypoglossal nerve then exits the brain through the hypoglossal canal, an opening situated near the large foramen magnum, which is the opening for the spinal cord.
After exiting the skull, the hypoglossal nerve travels downward, passing between important structures such as the internal carotid artery and the internal jugular vein. It loops around the occipital artery and continues forward, passing deep to the genioglossus muscle and towards the tip of the tongue. As it travels, it distributes branches that innervate the tongue muscles.
The hypoglossal nerve is susceptible to various conditions and injuries that can affect its function. For example, amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease can impact the nerve's ability to communicate with the brain. Encephalitis, an inflammation of the brain, can also cause compression on the hypoglossal nerve. Additionally, head and neck cancer treatments can disrupt nearby tissue, including the hypoglossal nerve.
Damage to the hypoglossal nerve can result in tongue deviation, muscle wasting, and fasciculations (muscle twitching). It can also lead to speech impairment, difficulty swallowing, and problems with chewing food. To test the function of the hypoglossal nerve, a physician may ask a patient to protrude their tongue and then palpate it to check the tone and sensation of the muscles.
Understanding Botox's Impact on Muscle Excretion
You may want to see also
Explore related products
It innervates the genioglossus, hyoglossus, styloglossus, and intrinsic muscles of the tongue
The hypoglossal nerve, or cranial nerve 12, is a motor nerve that innervates the genioglossus, hyoglossus, styloglossus, and intrinsic muscles of the tongue. These muscles are responsible for all movements of the tongue, including protruding, deviating, pushing the tongue forward, pulling it back, flattening it, and moving it up and down.
The genioglossus muscles push the tongue forward and lower its central part. They arise from the lower jaw (mandible) and attach to the entire length of the tongue. The left and right genioglossus muscles are responsible for protruding the tongue.
The hyoglossus muscles pull the tongue back, flatten it, and help with moving substances around in the mouth. They arise from the hyoid bone and attach to the side of the tongue.
The styloglossus muscles move the tongue up and down and pull it back into the mouth. They arise from the temporal bone and attach to the side of the tongue.
The intrinsic muscles are entirely inside the tongue and are responsible for actions such as shortening the tongue, curling its apex, turning it downward, narrowing and elongating it, and flattening and widening it.
The hypoglossal nerve originates from the hypoglossal nucleus in the lowest part of the brain, the medulla, and exits the skull through the hypoglossal canal. It then travels downward between the internal carotid artery and the internal jugular vein, passing around the hyoid bone and running along the hyoglossus muscle in the floor of the mouth.
Walking's Muscle-Preserving Benefits: What Science Says
You may want to see also
Explore related products
The nerve originates in the hypoglossal nucleus in the lower part of the medulla
The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a motor nerve that carries signals to and from the brain to control muscle movement. It is one of the 12 paired cranial nerves arising from the brain. It controls the muscles of the tongue, including the genioglossus, hyoglossus, styloglossus, and intrinsic muscles. These muscles are involved in moving and manipulating the tongue, as well as performing actions such as making clicking sounds, clearing the mouth of saliva, and moving substances around in the mouth.
The nerve originates in the hypoglossal nucleus, a thin and long nucleus located in the lower part of the medulla oblongata, near the midline. The hypoglossal nucleus is a 2-cm long cell column found in the ventral paramedian region of the medulla oblongata, beneath the hypoglossal trigone in the floor of the fourth ventricle. The neurons of this nucleus are multipolar, sending efferent fibers that extend anteriorly and laterally.
The hypoglossal nerve emerges as several small rootlets that join to form the nerve. These rootlets arise from the olives of the medulla, part of the brainstem, and pass through the hypoglossal canal in the occipital bone. The hypoglossal canal is an opening situated near the large opening for the spinal cord, the foramen magnum. After exiting the skull, the nerve travels downward between the internal carotid artery and the internal jugular vein, passing around the hyoid bone and running along the hyoglossus muscle in the floor of the mouth.
The hypoglossal nerve provides motor innervation to the vast majority of the muscles of the tongue. It innervates all intrinsic and almost all extrinsic muscles of the tongue, except for the palatoglossus muscle, which is innervated by the vagus nerve. The nerve is involved in controlling tongue movements required for speech, swallowing, and chewing, including sticking out the tongue and moving it from side to side.
Building Muscle: Understanding the Science of Muscle Growth
You may want to see also
Explore related products
It is also known as the twelfth cranial nerve, cranial nerve XII, or CN XII
The hypoglossal nerve is also known as the twelfth cranial nerve, cranial nerve XII, or CN XII. It is a motor nerve that carries signals to and from the brain to control muscle movement, specifically the muscles of the tongue. It is one of twelve cranial nerves and is paired, with one on each side of the body. The nerve originates in the hypoglossal nucleus in the lowest part of the medulla, which is part of the brainstem. It then exits the brain through the hypoglossal canal, which is an opening situated near the large opening for the spinal cord, the foramen magnum.
The hypoglossal nerve provides motor control of the extrinsic muscles of the tongue: genioglossus, hyoglossus, styloglossus, and the intrinsic muscles of the tongue. These muscles are involved in moving and manipulating the tongue, including sticking out the tongue and moving it from side to side. The nerve also innervates the thyrohyoid, omohyoid, sternohyoid, and sternothyroid muscles, which control the mandible and hyoid bones during speech and swallowing.
The hypoglossal nerve is responsible for all movements of the tongue, which are necessary for eating and speaking. It also enables the tongue to make noises, such as clicking sounds, and to move substances around in the mouth. The nerve has two lateral and terminal lingual branches, which carry fibres that innervate the dura mater on the floor and posterior wall of the posterior cranial fossa.
Damage to the hypoglossal nerve can result in tongue deficits, including difficulty speaking, swallowing, and chewing food. This damage can be caused by head and neck malignancy, penetrating traumatic injuries, or infection and inflammation of the brain.
Muscle Pump Benefits: How Does It Work?
You may want to see also
Explore related products
Disorders of the hypoglossal nerve make it difficult to speak, swallow, and chew food
The hypoglossal nerve, also known as cranial nerve XII, is a motor nerve that controls the tongue. It innervates the extrinsic and intrinsic muscles of the tongue, except for the palatoglossus, which is innervated by the vagus nerve. These muscles include the hyoglossus, genioglossus, styloglossus, and intrinsic muscles, which are responsible for tongue movement and manipulation.
Disorders of the hypoglossal nerve can cause significant difficulties with essential functions such as speaking, swallowing, and chewing food. This is because the nerve plays a crucial role in controlling the tongue and various muscles involved in these processes. When the hypoglossal nerve is damaged or disrupted, it can lead to weakness or atrophy of the tongue, making it challenging for individuals to move their tongues effectively.
Weakness or atrophy of the tongue can manifest in several ways. Individuals with hypoglossal nerve disorders may experience their tongue feeling "thick," "heavy," or "clumsy." The tongue may deviate to one side when stuck out, indicating damage to the nerve or its pathways. Additionally, individuals may have slurred speech, particularly with sounds that heavily depend on the tongue for articulation.
Hypoglossal nerve disorders can arise from various causes, including tumors, strokes, infections, injuries, amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease), encephalitis, head and neck cancer, and sleep apnea. Treatment options depend on the specific cause of the disorder. Doctors often use magnetic resonance imaging (MRI) and spinal taps to identify the underlying cause and then address it accordingly.
The impact of hypoglossal nerve disorders on speaking, swallowing, and chewing food highlights the critical role of this nerve in maintaining essential functions that we often take for granted. Early diagnosis and treatment are crucial to help manage the symptoms and improve an individual's quality of life.
Kaged Muscle: FDA Approved?
You may want to see also
Frequently asked questions
The hypoglossal nerve is a cranial nerve that enables tongue movement and control.
The hypoglossal nerve innervates the extrinsic tongue muscles and geniohyoid muscle, as well as all intrinsic muscles of the tongue except the palatoglossus, which is innervated by the vagus nerve.
Damage to the hypoglossal nerve can result in tongue deviation, muscle wasting, and fasciculations (twitching). It can also cause speech impairment and difficulty swallowing and chewing food.
To test the function of the hypoglossal nerve, a physician will ask the patient to stick out their tongue and examine its movements. They may also palpate the tongue to check the tone of the muscles and the ability to feel sensation.
