The lateral reticular nucleus, of the

lateral funiculus The most lateral of the bundles of the anterior nerve roots In anatomy and neurology, the ventral root of spinal nerve, anterior root, or motor root is the efferent motor root of a spinal nerve. At its distal end, the ventral root joins with the ...

, can be divided into three subnuclei, the parvocellular, magnocellular and the ''subtrigeminal''. As is typical of the reticular formation, none of these are very distinct subnuclei, but rather blurred distinctions between cell types and location. The lateral reticular nucleus sends all of its projections to the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cere ...

. * The parvocellular portion of the LRN and the immediately adjacent magnocellular portion send most their projections to the

vermis The cerebellar vermis (from Latin ''vermis,'' "worm") is located in the medial, cortico-nuclear zone of the cerebellum, which is in the posterior fossa of the cranium. The primary fissure in the vermis curves ventrolaterally to the superior surf ...

of the cerebellum. The rest of the magnocellular subnucleus sends its projections to the hemisphere regions of the cerebellum. * The subtrigeminal nucleus sends its projections to the

flocculonodular lobe The flocculonodular lobe ( vestibulocerebellum) is a lobe of the cerebellum consisting of the nodule and the flocculus. The two flocculi are connected to the midline structure called the nodulus by thin pedicles. It is placed on the anteroinferi ...

. All of these efferent pathways are projected in an

ipsilateral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

manner to the cerebellum, the most abundant of which are those to the vermis. This nucleus is also involved in the mediation of inspiration (in-breathing) with a part of the ventral r. nucleus. The afferent pathways to the LRN come from the spinal cord and higher brain structures. Most of the afferents come from the ipsilateral dorsal horn of the spinal cord and project exclusively to the parts of the LRN that do not receive input from the cortex. The spinal cord projections terminate mostly in the parvocellular region along with the adjacent magnocellular cells. This implies that most input from the spinal cord is relayed into the vermis.Jouvet, M. Handbook of clinical neurology vol 3. P. J. Vinken and G. W. Bruyen, eds. North Holland Publishing company. Amsterdam (1969)

References

{{Authority control Medulla oblongata