The anatomy of the nervous system, from the standpoint of development and function . ce the fibers of the facial nerve bendaround the abducens nucleus. Extending from the fovea superior to thecerebral aqueduct is a shallow groove, usually faint blue in color, the locus 121 THE NERVOUS SYSTEM car ulcus, beneath which lies the substantia ferruginea, composed of pigmentednerve-cells. Beginning at the cerebral aqueduct and extending through both the superiorand inferior fovea? is a very important groove, the sulcus limitans, which repre-sents the line of separation between the parts derived from t
The anatomy of the nervous system, from the standpoint of development and function . ce the fibers of the facial nerve bendaround the abducens nucleus. Extending from the fovea superior to thecerebral aqueduct is a shallow groove, usually faint blue in color, the locus 121 THE NERVOUS SYSTEM car ulcus, beneath which lies the substantia ferruginea, composed of pigmentednerve-cells. Beginning at the cerebral aqueduct and extending through both the superiorand inferior fovea? is a very important groove, the sulcus limitans, which repre-sents the line of separation between the parts derived from the alar plate andthose which originate from the basal plate of the embryonic to this sulcus lie the sensory areas of the ventricular floor, including thearea acustica, all of which are derived from the alar plate. Medial to thissulcus there is a prominent longitudinal elevation, known as the medial eminence,which includes two structures already described, namely, the facial colliculusand the trigone of the hypoglossal nerve. Beneath the medial part of this. Tela chorioidea Chorioid plexus Median aperture offourth ventricle Fig. 90.—Dorsal view of human rhombencephalon showing tela chorioidea and chorioid plexus of the fourth ventricle. trigone lies the nucleus of the hypoglossal nerve and beneath the lateral part is agroup of cells designated as the nucleus intercalatus. One or two features remain to be mentioned. At the caudal end of the alacinerea is a narrow translucent obliquely placed ridge of thickened ependyma,known as the funiculus scparans. Between this ridge and the clava is a smallstrip of the ventricular floor, called the area post rem a. which on microscopicexamination is found to be rich in blood-vessels and neurogliar tissue. The roof of the fourth ventricle is formed by the anterior medullary velum,a small part of the white substance of the cerebellum, and by the tela chorioidealined internally by cpendymal epithelium (Fig. 85). Caudal
Size: 1396px × 1789px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectnervoussystem, bookye
