División Paleontología Vertebrados, Museo de La Plata (Unidad de Investigación Anexo), Facultad de Ciencias Naturales y Museo, CONICET, Buenos Aires, Argentina.
Instituto de Investigaciones en Paleobiología y Geología, Universidad Nacional de Río Negro y Museo Carlos Ameghino, CONICET, Cipolletti, Argentina.
J Anat. 2019 Jun;234(6):875-898. doi: 10.1111/joa.12975. Epub 2019 Mar 22.
Sharpey's fibers are considered the anatomical structures integrated to the muscles. Since these fibers leave marks at the microscopic level, their presence and distribution are used as evidence of muscle attachment in extinct and extant forms. In recent years, studies have been focusing on muscle-bone and tendon-bone interaction mostly on mammals. The main objective of this work is to contribute to the morphological and histological knowledge of muscle attachment in other amniotes, such as reptiles, and their variation related to different locomotor habits. In this way, a study was performed on terrestrial and aquatic turtles. The musculature related to the movement of the humerus, and pectoral girdle in Chelonoidis chilensis, Phrynops hilarii and Hydromedusa tectifera was analyzed. Dissections were performed mapping the origins and insertions of each muscle and undecalcified thin sections were performed in specific muscular attachment sites. We found some differences which were not previously reported, related to the insertion of the m. pectoralis, the m. coracobrachialis magnus and the origin of the m. tractor radii. The osteohistology revealed the presence of Sharpey's fibers in the cortex of all the bone elements analyzed. Patterns were established in relation to the orientation and density of Sharpey's fibers, which were used for the categorization of each muscle attachment site. The comparative micro-anatomical study of these areas did not reveal any important differences between terrestrial and freshwater turtles in muscles involved with the rotation, abduction and adduction of the humerus. In this way, the preliminary results suggest an absence of correlation between the distribution and density of Sharpey's fibers between different habitat forms, at least in the bones and species analyzed.
Sharpey 纤维被认为是与肌肉整合在一起的解剖结构。由于这些纤维在微观水平上留下痕迹，因此它们的存在和分布被用作在已灭绝和现存形式中肌肉附着的证据。近年来，研究主要集中在肌肉-骨骼和肌腱-骨骼相互作用上，主要是在哺乳动物上。这项工作的主要目的是为其他羊膜动物（如爬行动物）的肌肉附着的形态学和组织学知识做出贡献，并研究与不同运动习惯相关的变化。为此，对陆生和水生龟类进行了研究。分析了 Chelonoidis chilensis、Phrynops hilarii 和 Hydromedusa tectifera 中与肱骨和胸带运动相关的肌肉。通过对每个肌肉的起点和止点进行映射来进行解剖，并在特定的肌肉附着部位进行未脱钙的薄切片。我们发现了一些以前没有报道过的差异，与 m. 胸大肌、m. 肱二头肌和 m. 桡骨牵引肌的止点有关。骨组织学显示，在所分析的所有骨骼元素的皮质中都存在 Sharpey 纤维。根据 Sharpey 纤维的方向和密度建立了模式，用于对每个肌肉附着部位进行分类。对这些区域的比较微观解剖学研究表明，在涉及肱骨旋转、外展和内收的肌肉中，陆生和淡水龟之间没有明显的差异。因此，初步结果表明，在不同栖息地形式之间，Sharpey 纤维的分布和密度之间不存在相关性，至少在所分析的骨骼和物种中是这样。
