MICROSTRUCTURE AND MECHANICAL DESIGN IN THE LANTERN OSSICLES OF THE REGULAR SEA-URCHIN PARACENTROTUS-LIVIDUS - A SCANNING ELECTRON-MICROSCOPE STUDY
MICROSTRUCTURE AND MECHANICAL DESIGN IN THE LANTERN OSSICLES OF THE REGULAR SEA-URCHIN PARACENTROTUS-LIVIDUS - A SCANNING ELECTRON-MICROSCOPE STUDY
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DOI：
10.1080/11250009109355726
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发表时间：
1991-01-01
期刊：
影响因子：
--
通讯作者：
MELONE, G
中科院分区：
文献类型：
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作者：
CARNEVALI, MDC;BONASORO, F;MELONE, G
棘皮动物是棘皮动物的一类，它在一系列极其先进和复杂的适应性解决方案中最有效地探索和利用内骨骼的潜力。这些适应性中最巧妙的是用于牙科设备，其不同的元素代表了骨骼组织的多功能性的显著例子。牙齿听小骨(颌骨、圆盘、圆规和牙齿)虽然具有相同的基本组织结构，但显示出广泛的结构和功能解决方案：无机相和有机基质以不同的方式组合和集成在一个非常可塑性和适应性很强的组织中，能够满足非常特殊的机械要求。总体而言，牙齿单元所表现出的所有不同排列可以认为是骨骼微结构的两种极限模型的区别，分别以经典的多孔立体结构和复合材料的片层结构为代表。第一种结构模型是迄今为止最常见的：除牙齿外，所有的灯笼听骨都在三维立体主题上显示了相当完整的各种变化，包括通常的迷宫图案或其他类型的更专门的立体图案(层状、廊状、束状、微穿孔、闭锁)，它们的存在与相互作用的元素(韧带、肌肉、其他骨骼部分)和特定的功能要求密切相关。在任何情况下，都可以很容易地观察到表面和内部立体微结构之间的显著差异，以及相关基质的分布和组织的许多明显变化。相反，第二种模式只能在牙齿中检测到，并由独特的复合结构(初级和次级元素)组成，在不同的区域显示出许多特定的差异：初级结构由独特的矿物元素(板层和棱柱)组成，构成牙齿的主要骨架；二级结构相反，由或多或少修改结构的立体板组成，它们粘结和加强初级结构。牙齿是真正的结构设计杰作，无机和有机成分合作，实现了一种非常坚硬的结构，可以抵抗不同类型的机械应力。根据现有的灯笼力学知识，讨论了这两种不同结构解的意义以及它们众多变化的功能含义。
Echinoids are the echinoderm group which has explored and exploited most efficiently the potential of the endoskeleton in a range of extremely advanced and sophisticated adaptive solutions. The most ingenious of these adaptations are employed in the dental apparatus, whose different elements represent a striking example of the versatility of the skeletal tissue. The dental ossicles (jaws, rotulae, compasses and teeth), though having the same basic organization, show a wide range of structural and functional solutions: inorganic phase and organic stroma are variously combined and integrated in a very plastic and adaptable tissue, which is able to fulfil very specific mechanical requirements. On the whole, all the different arrangements shown by the dental elements can be considered as differentiations of the two limit-models of skeletal microarchitecture, represented respectively by classical porous stereom and a composite lamellar structure. The first structural model is by far the most common: all the lantern ossicles, except the tooth, show a rather complete range of variations on the theme of the three-dimensional stereom, including either the usual labyrinthic pattern or other types of more specialized stereoms (laminar, galleried, fascicular, microperforate, imperforate), whose presence is closely related to the association with interacting elements (ligaments, muscles, other skeletal parts) and to specific functional requirements. In any case, remarkable differences can be observed easily between the superficial and the internal stereom microstructure, in parallel with as many conspicuous variations in the distribution and the organization of the associated stroma. The second model, on the contrary, can be detected only in the tooth and consists of a unique composite structure (primary and secondary elements), showing a number of specific differentiations in different zones: the primary structure consists of unique mineral elements (lamellar plates and prisms), which form the main framework of the tooth; the secondary structure, on the contrary, consists of stereom plates of more or less modified structure, which cement and reinforce the primary structure. The tooth is a true masterpiece of constructional design, where inorganic and organic components co-operate to achieve a structure which is remarkably hard and resistant to different types of mechanical stress. The significance of these two different structural solutions and the functional implications of their numerous variations are discussed in the light of current knowledge of lantern mechanics.