- 期刊
人類顳骨切片於胎兒與成人之耳蝸導水管之型態比較
Morphologic Comparison of Cochlear Aqueduct Between Fetus and Adult in Human Temporal Bone Sections
摘要
背景：耳蝸導水管（cochlear aqueduct）連接蛛網膜下腔（subarachnoid space），與耳蝸基底圈（cochlear base turn）之鼓室階（scala tympani）。其功能雖被認為涉及內耳迷路之淋巴，然而相關的研究文獻並不多見。因內耳膜迷路（membranous labyrinth）之胚胎來源與耳蝸導水管之胚胎來源不同。所以耳蝸導水管與內耳迷路間之關係仍有待釐清。研究擬比較胎兒與成人之耳蝸導水管與內耳間之形態差異，以探尋研究耳蝸導水管與內耳迷路間之關係的可能研究方向。方法：7名胎兒顳骨及9名成人顳骨。經固定、脫鈣、包埋、切片、染色、並封片後，製成厚20 μm之連續顳骨切片。於光學顯微鏡下作影像之檢讀研究分析。結果：成人之Cotugno氏管及鼓室腦膜裂（tympanomeningeal fissure ; Hyrtl’s fissure）因骨化而閉鎖，與胎兒之寬大及充滿中胚層組織不同。但胎兒與成人之耳蝸導水管於耳蝸基底圈之鼓室階的耳蝸導水管開口（外孔）處，均維持為開放孔，未因發育成長而閉鎖或起變化，其型態亦無差異。結論：胎兒與成人之耳蝸導水管，於耳蝸基底圈之鼓室階處的耳蝸導水管開口（外孔）處，其型態保持未變；顯示胎兒與成人之耳蝸導水管（cochlear aqueduct）間之差異僅止於Cotugno氏管及鼓室腦膜裂之變化，未及於耳蝸基底圈之鼓室階的耳蝸導水管開口（外孔）處。這顯示內耳結構不受耳蝸導水管之發展變化的影響。故有關耳蝸導水管之研究宜聚焦於Cotugno氏管及鼓室腦膜裂之變化。
並列摘要
BACKGROUND: The cochlear aqueduct connects the subarachnoid space and scala tympani of cochlear basal turn. The function of cochlear aqueduct was considered to be concerned with perilymph of inner ear. However the different embryologic origin makes the relationship between cochlear aqueduct and labyrinth of inner ear ambiguous. In order to figure out possible research direction concerning the relationship between cochlear aqueduct and inner ear, this study compared the morphologic difference of cochlear aqueduct between fetus and adult in human temporal bone sections. METHODS: Temporal bone sections of 7 fetus and 9 adults were used. After fixation, decalcification, embedding, section, staining, and processing to 20μm continuous slides, the images were studied under optical microscope. RESULTS: The Cotugno's canal and tympanomeningeal fissure (Hyrtl’s fissure) are obliterated by ossification in adult cochlear aqueduct. However, the fetal cochlear aqueduct contains much mesoderm and loose connective tissue. The inner orifice of cochlear aqueduct at the cochlear basal turn of fetus and adult remains the same, and there is even no morphologic difference between that of fetus and adult. CONCLUSIONS: The same morphology of the inner orifice of cochlear aqueduct of fetus and adult indicated that the difference of cochlear aqueduct between fetus and adult limits at the change of Cotugno's canal and tympanomeningeal fissure. The structure of inner ear was spared. Further study on the cochlear aqueduct may focus on Cotugno's canal and tympanomeningeal fissure.