• The nuclei contain large motor neurons and myelinated fibers of the hypoglossal nerve, innervating the intrinsic and extrinsic tongue muscles , excluding palatoglossus 1,2 which is innervated by the vagus nerve . (radiopaedia.org)
  • The hypoglossal nuclei , exist as paired nuclei within the medulla oblongata that provide motor innervation to the intrinsic and extrinsic muscles of the tongue (excluding palatoglossus) via the hypoglossal nerve . (radiopaedia.org)
  • Fibers pass anteriorly between the inferior olivary nucleus and pyramid and exit the medulla as the hypoglossal nerve between the pyramid and olive. (radiopaedia.org)
  • Extensive interconnections exist between many of these nuclei, as well as with other brainstem nuclei and white matter tracts, such as the medial lemniscus and medial longitudinal fasciculus . (radiopaedia.org)
  • The hypoglossal nuclei are located within the tegmentum of upper medulla close to the midline, lying deep to the hypoglossal trigone , or hypoglossal triangle, which is the medial eminence of the floor of the fourth ventricle , inferior to the stria medullaris 1 . (radiopaedia.org)
  • They lie ventral and medial to the dorsal vagal nucleus . (radiopaedia.org)
  • Functionally, the nuclei can be divided dorsally and ventrally, and into medial and lateral components to achieve a musculotopic organization of the motor neurons within. (radiopaedia.org)
  • The cranial nerve nuclei are a series of bilateral grey matter motor and sensory nuclei located in the midbrain , pons and medulla that are the collections of afferent and efferent cell bodies for many of the cranial nerves . (radiopaedia.org)
  • Each nucleus is approximately 2 cm in length, extending beyond the limits of the hypoglossal trigone into the region of the closed medulla. (radiopaedia.org)
  • Some nuclei are small and contribute to a single cranial nerve, such as some of the motor nuclei. (radiopaedia.org)
  • Several motor and sensory nuclei form longitudinal columns in the brainstem, leading to some authors describing them as single discontinuous longitudinal nuclear columns rather than the more numerous individual separate nuclei. (radiopaedia.org)
  • A nucleus located in the middle hypothalamus in the most ventral part of the third ventricle near the entrance of the infundibular recess. (nih.gov)
  • An aggregation of cells in the middle hypothalamus dorsal to the ventromedial nucleus and bordering the third ventricle. (nih.gov)