Biomaterial Database

[Reissner's fiber in the central canal of primate spinal cord]. 1983

H Erhardt, and W Meinel

The Reissner's fibre (RF) in the canalis centralis of the spinal cord was studied with the aid of transmission and scanning electron microscope in Tupaia, Cebus, Sarmiri, Macaca, Alouatta, Ateles, Callithrix and Callicebus. The RF of the primates is structurally not different from the corresponding structure of other chordates. The diameter of the RF is slightly increasing in the canalis direction. The increase of the diameter varies between 2 and 5 micron. It is assumed that the increase is brought about by the inclusion of cell debris into the fibre. Material which definitely does not belong to the RF is found in the cerebrospinal fluid (CSF) of the canalis centralis and occasionally it adheres to the surface of the fibre. This material appears either as amorphous flocculent substances, the granulation of which differs in both density and size of the granula or as vesicles. If the material makes contact with the RF, a membrane-like structure may appear which is a condensation restricted to the area of the contact between material of different viscosity and granulation. The origin of this variable material is still not clarified. According to our observations, it is probably sequestrated material from ependymal cells. It is not a secretion as sometimes assumed since the intracellular processes of the synthesis of the secretion have not been observed.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D011323	Primates	An order of mammals consisting of more than 300 species that include LEMURS; LORISIDAE; TARSIERS; MONKEYS; and HOMINIDS. They are characterized by a relatively large brain when compared with other terrestrial mammals, forward-facing eyes, the presence of a CALCARINE SULCUS, and specialized MECHANORECEPTORS in the hands and feet which allow the perception of light touch.	Primate
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013116	Spinal Cord	A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.	Coccygeal Cord,Conus Medullaris,Conus Terminalis,Lumbar Cord,Medulla Spinalis,Myelon,Sacral Cord,Thoracic Cord,Coccygeal Cords,Conus Medullari,Conus Terminali,Cord, Coccygeal,Cord, Lumbar,Cord, Sacral,Cord, Spinal,Cord, Thoracic,Cords, Coccygeal,Cords, Lumbar,Cords, Sacral,Cords, Spinal,Cords, Thoracic,Lumbar Cords,Medulla Spinali,Medullari, Conus,Medullaris, Conus,Myelons,Sacral Cords,Spinal Cords,Spinali, Medulla,Spinalis, Medulla,Terminali, Conus,Terminalis, Conus,Thoracic Cords
D013351	Subcommissural Organ	Ependymal derivative located at the junction of the THIRD VENTRICLE and the CEREBRAL AQUEDUCT; and the SOMATOSTATIN SECRETING CELLS.	Organ, Subcommissural,Organs, Subcommissural,Subcommissural Organs