筛骨基板及相关结构的胚胎学显微解剖研究

Microanatomical study on embryology of ethmoidal basal lamella and related structures

目的通过对不同胎龄的胎儿鼻腔结构的解剖观察,了解鼻腔结构,尤其是筛骨各基板、气房发育规律及特点,为临床鼻窦外科学提供理论支撑。方法取9个(共18侧)24~38周胎龄的胎头标本,正中裂开后去除鼻腔黏膜,观察筛骨各基板层次以及基板间骨或软骨结构之间的连接方式。结果①24~38周胎儿筛骨均同时存在钩突、中鼻甲、上鼻甲及最上鼻甲结构,最上鼻甲、筛骨水平板以软骨形式存在,各基板在顶部为软骨样组织与筛骨水平板融合在一起构成颅底,相邻基板在筛骨下方外侧壁上有骨性连接在一起;②钩突头端与筛泡上端有倒"U"骨板连接,且早期即可观察到额隐窝雏形;③筛骨外侧壁上骨质厚薄不一,相邻基板间存在多个骨性隆起和凹陷,且随胎龄增大而出现隆起明显和凹陷加深,这些骨性隆起所围成的凹陷即为早期的引流通道。结论通过显微解剖观察,在胚胎学上再次确认钩突与筛泡的骨性连接及基板层次,毗邻基板间在筛骨外侧壁上的骨性隆起(即连接板)将基板间划分为有序的引流通道,为临床鼻窦外科学建立解剖基础。

Objective To provide theoretical support for clinical sinus surgery by realizing the developmental rules and characteristics of the nasal structures,especially the basal lamellae and cells of ethmoidal bone,through the microanatomical observation of the fetal nasal structures of different gestational ages.Methods Nine(a total of 18 sides)fetal cadaveric head specimens of 24-38 weeks gestational age were obtained.The nasal mucosae were removed after median rupture,and the lamellar layers of the ethmoid as well as the bony or cartilaginous connections between the lamellae were observed.Results①From fetal weeks 24 to 38,uncinate process,middle turbinate,superior turbinate and supreme turbinate were presented in the ethmoid bone.The superior turbinate and ethmoid horizontal plate existed in the form of cartilage.The cephalic cartilage-like tissues of all lamellae were fused together with ethmoid horizontal plate to form skull base,and bony connections were found between adjacent lamellae on the lateral wall below the ethmoid bone.②The cephalic end of uncinate process had an inverted U-shaped bone plate connection with the upper end of ethmoidal bulb,and the embryo frontal recess could be observed at early stage.③The thickness of the lateral ethmoid wall was variable.Multiple bony ridges and depressions existing between adjacent lamellae got obvious with the gestational age.The depression formed by these bony ridges was early drainage pathway.Conclusions Microanatomical observations re-confirm the skeletal junction between the uncinate process and ethmoidal bulb as well as the level of the basal lamella in embryology.The bony bulges(also known as connecting plates)among adjacent lamellae on the lateral wall of the ethmoid divide inter-lamellar spaces into orderly drainage pathways,which establishes an anatomical basis for subsequent development of ethmoid sinus.