Cranial nerve nuclei - posterior view (efferent) (Latin)

The nuclei of origin of efferent (motor) fibers are organized into discontinuous longitudinal columns within the truncus encephali. The general somatic efferent nuclei lie closest to the midline and are made up of the ncl. nervi oculomotorius, ncl. nervi trochlearis, ncl. nervi abducentis and ncl. nervi hypoglossi. These nuclei can also be identified from a sagittal view (see next image). The ncll. nervi oculomotorius and trochlearis are located in the mesencephalon at the level of the colliculi superioris et inferioris. The ncl. nervi abducentis lies in the lower part of the pons, while the ncl. nervi hypoglossi is situated within the lower medulla oblongata. These nuclei are composed of lower motor neurons and are responsible for innervating striated (skeletal) muscles of somatic origin, specifically the voluntary muscles of the eye (oculus) and tongue (lingua). Special visceral efferent nuclei, also known as the branchial efferent or branchiomotor nuclei, are made up of the ncl. motorius nervi trigemini, the ncl. nervi facialis and the ncl. ambiguus (See next image to identify these nuclei from a sagittal perspective). The ncl. motorius nervi trigemini and the ncl. nervi facialis are located in the pons, while the ncl. ambiguus is situated in the medulla oblongata. The ncl. ambiguus communicates with the nn. glossopharyngeus, vagus and accessorius. The special visceral efferent nuclei function to supply striated (skeletal) muscles derived from the branchial arches such as the stylopharyngeus muscle (m. stylopharyngeus) or some of the muscles of facial expression.