Some modifications in the vascular system of marine mammals provide adaptive advantages for diving. This study analyses the organisation of the aortic wall in dolphins, observing artery changes in volume and blood pressure for diving behaviour. Samples of three aortic segments (ascending, thoracic and abdominal) of three dolphin species were processed for histological and morphometric studies. The three dolphin species used, striped dolphin (Stenella coeruleoalba), Atlantic spotted dolphin (Stenella frontalis) and common dolphin (Delphinus delphis), have shallow or intermediate diving habits. Our results indicated that the components of the aortic wall of the dolphins had different dispositions in the three selected segments. The aortic wall decreased in thickness along its length due to a loss of the lamellar units in the tunica media and a thinning of the main elements of the lamellar units along the artery. The life stage had little influence on the thickness of the aortic wall except for the ascending aorta. The weight, body length, species or sex of the specimen did not significantly influence the thickness of the wall or the lamellar units. In summary, the histological and morphometric aortic structure in dolphins, in relation to the studied parameters, seems to be similar to that previously described of terrestrial mammals such as pigs, except for a larger difference in the proportion of lamellar units between the ascending and thoracic segments.

中文翻译：

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具有浅潜水或中潜水习性的三种海豚科动物的主动脉壁形态结构：潜水适应的证据

海洋哺乳动物血管系统的一些改变为潜水提供了适应性优势。这项研究分析了海豚主动脉壁的组织，观察了潜水行为的动脉容积和血压变化。对三种海豚的三个主动脉段（升、胸和腹）的样本进行了处理，用于组织学和形态学研究。所使用的三种海豚，即条纹海豚 (Stenella coeruleoalba)、大西洋斑点海豚 (Stenella frontalis) 和普通海豚 (Delphinus delphis)，具有浅潜水或中潜水习性。我们的结果表明，海豚主动脉壁的组成部分在三个选定的节段中具有不同的倾向。由于中膜中层状单位的损失和沿动脉的层状单位的主要成分变薄，主动脉壁沿其长度方向的厚度减少。除升主动脉外，生命阶段对主动脉壁厚度影响不大。标本的重量、体长、物种或性别对壁厚或层状单位没有显着影响。总之，海豚的组织学和形态测量主动脉结构，与研究参数相关，似乎与先前描述的陆生哺乳动物（如猪）相似，只是上升和胸部之间的层状单位比例差异更大。段。除升主动脉外，生命阶段对主动脉壁厚度影响不大。标本的重量、体长、物种或性别对壁厚或层状单位没有显着影响。总之，海豚的组织学和形态测量主动脉结构，与研究参数相关，似乎与先前描述的陆生哺乳动物（如猪）相似，只是上升和胸部之间的层状单位比例差异更大。段。除升主动脉外，生命阶段对主动脉壁厚度影响不大。标本的重量、体长、物种或性别对壁厚或层状单位没有显着影响。总之，海豚的组织学和形态测量主动脉结构，与研究参数相关，似乎与先前描述的陆生哺乳动物（如猪）相似，只是上升和胸部之间的层状单位比例差异更大。段。