What is the role of the hypoglossal nerve?

What is the role of the hypoglossal nerve?

The hypoglossal nerve enables tongue movement. It controls the hyoglossus, intrinsic, genioglossus and styloglossus muscles. These muscles help you speak, swallow and move substances around in your mouth.

What is the main function of CN XII?

The hypoglossal nerve (CN XII) is exclusively a motor nerve carrying general somatic efferent fibers (GSE). It innervates all intrinsic and almost all extrinsic muscles of the tongue, as well as one suprahyoid muscle, the geniohyoid muscle.

What is nerve accessory?

The accessory nerve is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles. It is considered as the eleventh of twelve pairs of cranial nerves, or simply cranial nerve XI, as part of it was formerly believed to originate in the brain.

Where do you find the rootlets of the hypoglossal nerve?

The rootlets of the hypoglossal nerve arise from the hypoglossal nucleus near the bottom of the brain stem. The hypoglossal nucleus receives input from both the motor cortices but the contralateral input is dominant; innervation of the tongue is essentially lateralized.

Is hypoglossal nerve contralateral or ipsilateral?

Hypoglossal (Twelfth) Each nerve innervates the ipsilateral tongue muscles. These muscles move the tongue within the mouth, protrude it, and push it to the contralateral side. With equal muscle innervation, each side’s strength is balanced and the tongue sits or protrudes in the midline.

How do you assess CN XII?

12th Cranial nerve The 12th (hypoglossal) cranial nerve is evaluated by asking the patient to extend the tongue and inspecting it for atrophy, fasciculations, and weakness (deviation is toward the side of a lesion).

What nerve supplies sternocleidomastoid?

The sternocleidomastoid muscle is generally considered to have nerve supply from the accessory nerve. However, the innervation pattern to the SCM is not so simple and it also receives fibers from the C2 and C3 anterior branches, as studied by Caliot et al.

What happens if the spinal accessory nerve is damaged?

The spinal accessory nerve originates in the brain and enables motion in the trapezius and sternomastoid muscles in the neck. A spinal accessory nerve injury can be caused by trauma or damage during surgery, resulting in shoulder pain, “winging” of the shoulder blades and weakness of the trapezius muscle.

What causes uvula deviation?

Central lesions of the vagus nerve can cause dysphagia, dysarthria and hoarseness; uvula deviation (towards the opposite side of the lesion); and transient parasympathetic effects.

What is the structure of the hypoglossal nerve?

Structure. The hypoglossal nerve arises as a number of small rootlets from the front of the medulla, the bottom part of the brainstem, in the anterolateral sulcus which separates the olive and the pyramid. The nerve passes through the subarachnoid space and pierces the dura mater near the hypoglossal canal,…

Can the hypoglossal nerve be damaged?

Though it is a rare occurrence that any damage can be caused to the Hypoglossal Nerve, it is mostly gunshot wounds and compression caused by tumors can result in damage to this nerve.

What are the causes of hypoglossal disease?

These include surgical damage, medullary stroke, multiple sclerosis, Guillain-Barre syndrome, infection, sarcoidosis, and presence of an ectatic vessel in the hypoglossal canal. Damage can be on one or both sides, which will affect symptoms that the damage causes.

What nerve is responsible for tongue movement?

Hypoglossal nerves (XII) is only motor, controlling tongue movements. These nerves originate in the motor nuclei of the medulla, passing through the hypoglossal canals of the occipital bone, to reach the tongue muscles.