Neuroanatomy, Pons

Excerpt

The pons is the portion of the brainstem between the midbrain above and the medulla oblongata below. The transverse section of pons is subdivided into 2 areas: the ventral and the dorsal. The ventral portion of pons contains pontine nuclei, vertically traversing corticopontine and corticospinal tracts, and transversely crossing fibers arising from pontine nuclei that project to the opposite cerebellum through the middle cerebellar peduncle. The ventral segment of the pons is bulky due to the pontine nuclei and their connection to the corticopontocerebellar.

The dorsal part of the pons, also known as the tegmentum, is occupied mainly by the reticular formation. The tegmentum is bounded laterally and superiorly by the inferior cerebellar peduncle in the superior cerebellar peduncle. Internal structures of the pons are usually described along with anatomical landmarks; structures at upper pons are mainly superior cerebellar peduncles, medial longitudinal fasciculus, locus coeruleus, pedunculopontine tegmental nucleus, and parabrachial nucleus. The transverse section at the middle cerebellar peduncle shows the trapezoid body, medial lemniscus, lateral lemniscus, and trigeminal nucleus (sensory and main motor). Pontine structures at the level of the facial nucleus are the abducens nerve nucleus, facial nerve nucleus, and vestibular nuclei.