Hypoglossal nerve

Hypoglossal nerve is the twelfth cranial nerve in the human body. It is responsible for the movement of most of the muscles in the tongue, and is thus an important factor in speech, swallowing, and other functions.

Anatomy

The hypoglossal nerve originates in the medulla oblongata, a part of the brainstem. It travels through the hypoglossal canal, a small passage in the occipital bone of the skull, before it reaches the tongue.

Function

The hypoglossal nerve controls the movement of the tongue. It is responsible for the contraction of the muscles that allow the tongue to move in various directions, such as protrusion, retraction, and side-to-side movement. This is crucial for several functions, including speech, swallowing, and cleaning the oral cavity.

Clinical significance

Damage to the hypoglossal nerve can result in hypoglossal nerve palsy, a condition characterized by a loss of control over the tongue muscles. This can lead to difficulties with speech and swallowing, and in severe cases, can cause the tongue to atrophy and deviate towards the side of the injury.

See also

• Cranial nerves
• Medulla oblongata
• Occipital bone
• Hypoglossal nerve palsy

References

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  Anterior view of the human brainstem
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  Illustration from Sobo 1909
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  Hypoglossal nerve
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  Diagram from Lawrence 1960
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  Unilateral hypoglossal nerve injury