The anatomy of the nervous system, from the standpoint of development and function . on some distance from the THK CRANIAL NKRVKS AND T1IKIK M I II I 75 ventricular floor (Figs. 110, 121, 122). The fibers, which take their origin here, arc collected in the motor root or portio minor of the fifth nerve and run with iimandibular division to the muscles of mastication. Within the nucleus then-terminate fibers from the corticobulbar tract and many fibers, chiefly collateralsfrom the central sensory tract of the trigeminal nerve. It also receives collat-erals from the mesencephalic root of the trig
The anatomy of the nervous system, from the standpoint of development and function . on some distance from the THK CRANIAL NKRVKS AND T1IKIK M I II I 75 ventricular floor (Figs. 110, 121, 122). The fibers, which take their origin here, arc collected in the motor root or portio minor of the fifth nerve and run with iimandibular division to the muscles of mastication. Within the nucleus then-terminate fibers from the corticobulbar tract and many fibers, chiefly collateralsfrom the central sensory tract of the trigeminal nerve. It also receives collat-erals from the mesencephalic root of the trigeminal and from other sources(Fig. 131). The motor nucleus of the facial nerve is located in the ventrolateral partof the reticular formation of the pons near its caudal border (Figs. 108, 121,122). Its constituent cells are arranged so as to form a varying number of sub-groups which may possibly be concerned with the innervation of individual facialmuscles. Root of facial nerve, first partIbducens nucleus Root of facial nerve, genu Root of facial nerve, second partFacial nucleus. Nucleus of ahducens nerve Root filaments of ahducens nerve Stalk of superior olive Root of facial nerve, first partSpinal root and nuch u ATA ucleus of facial mRoot official ) olive [part A bducens nerve Fig. 124.—Diagram of the root of the facial nerve, shown as if exposed by dissection in a thick section of the pons. From the dorsal aspect of this nucleus there emerge a large number of finebundles of libers, directed dorsomedially through the reticular formation. Theserather widely separated bundles constitute the first part of the root of the facialnerve (Fig. 124). Beneath the floor of the fourth ventricle the fibers turn sharplyrostrad and are assembled into a compact strand of longitudinal fibers, oftencalled the ascending part of the facial nerve. This ascends along the medial sideof the abducens nucleus dorsal to the medial longitudinal bundle for a consid-erable distance (5 mm.).
Size: 1863px × 1341px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectnervoussystem, bookye
