Point 16











Point 16. Pontine Nuclei and the Middle Cerebellar Peduncle

As presented earlier, the pons is divided into two portions: the dorsal portion called the pontine tegmentum, and a ventral part referred to as the basilar pons.

The ventral portion of the pons is a massive structure that consists of orderly arranged transverse and longitudinal fiber bundles between which are large collections of pontine neurons called the PONTINE GREY (or GRAY). The longitudinal bundles are (1) corticobulbar, (2) corticospinal and, most important for this point, (3) CORTICOPONTINE FIBERS.

I have briefly touched on some of the connections and functions of the cerebellum when discussing the accessory cuneate nucleus (POINT #5) and the inferior olivary complex (POINT# 6). There will also be two lectures on the cerebellum. Right now, you need to know that CORTICOPONTINE fibers convey information from motor related areas of cortex (i.e., the cells of origin) to neurons in the IPSILATERAL pontine grey (pontine grey neurons). More specifically, corticopontine axons convey to the pontine grey neurons information that is used in the planning and initiation of movements. These planning and initiation data are then sent to the CONTRALATERAL cerebellum by another projection called the pontocerebellar.

Level 5. Middle Pons - Facial Colliculus

Level 5. Middle Pons - Facial Colliculus

Brainstem - Ventral View

Brainstem - Dorsal View