Hypoglossal nerve root (CN XII)

Radix nervi hypoglossi

NervousOrgansHead

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What it is
A line of rootlets leaving the preolivary sulcus between the pyramid and the olive of the medulla. Shown as a short stub on both sides; the nerve continues in the peripheral nervous system.
Function
Motor to the muscles of the tongue.
Size
Stub about 1 cm; root 1.4 mm thick
Clinical note
A lesion makes the protruded tongue deviate toward the weak side.

Nearby nervous structures Abducens nerve root (CN VI), Accessory nerve root (CN XI), C1 spinal nerve, Facial nerve root (CN VII), Glossopharyngeal nerve root (CN IX), Medulla oblongata, Pons, Trigeminal nerve root (CN V), Vagus nerve root (CN X), Vestibulocochlear nerve root (CN VIII)