The investigation of intracranial part and histology of the optic nerve

SUMMARYOptic nerve (Cr2) mediates sense of vision and has a large number of fibers andalso it has important relationships. It contains special somatic afferent fibers, hascomplex connections and plays a primary role in vision. Due to many problemsresulting from the Cr2 itself or related structures, this nerve or the related structuresmay be frequently operated. That is why the knowledge of the Cr2 is essential.In our study intracranial parts of 40 Cr2?s and also optic chiasmas (CO) from20 forensic autopsy cadavers were taken and examined and also tissue samples wereobtained. The intracranial course of Cr2?s and CO?s were carefully noted. Possibletypes of variations were investigated. Then tissue samples were stained withHematoxylin and Eosin for histological investigation.Macroscopically, after entering the cranial cavity via the optic foramen, Cr2?shad a converging course until they formed the CO. The shape of the cross sections ofthe Cr2 was cylindrical but it became oval as it came closer to the CO. Atrophic orhypoplasic Cr2?s were not found in the examined cadavers. The measurementsrevealed that the intracranial length of Cr2 was 11.1±1.02 mm in the right and9.9±0.92 mm in the left.CO?s were in close relation with internal carotid arteries on each side. Wefound that the width, anteroposterior length and the height of CO were 12.68±0.95mm, 8.75±01.15 mm and 4.32 ±0.25 mm respectively.Microscopically, intrapial width and intrapial height of the Cr2?s weremeasured as 3.69±0.27 mm and 2.85 ±0.19 mm respectively. The intrapial width ofCO?s was found to be 11.67± 0.92 mm. The intrapial height in the median line ofCO2?s was 2.62±0.17 mm.As a result we believe that the results obtained by the examination of theintracranial part of the Cr2 and by the histological investigations will contribute tothe demography of our country. These data will also help the clinicians andcontribute to the researchers who will study in this field.Key words: optic nerve, optic chiasm, anatomy, histology.PDF created with pdfFactory trial version www.pdffactory.com