The morphological and histological features of the nasal cavity are diverse among animal species, and the nasal cavities of terrestrial and semiaquatic turtles possess 2 regions lined with each different type of sensory epithelium. Sea turtles can inhale both of volatile and water-soluble odorants with high sensitivity, but details of the architectural features and the distribution of the sensory epithelia within the sea turtle nasal cavity remain uncertain. The present study analyzed the nasal cavity of green sea turtles using morphological, computed tomographic, and histological methods. We found that the middle region of the sea turtle nasal cavity is divided into anterodorsal, anteroventral, and posterodorsal diverticula and a posteroventral excavation by connective tissue containing cartilages. The posterodorsal diverticulum was lined with a thin sensory epithelium, and the anterodorsal and anteroventral diverticula were occupied by a single thick sensory epithelium. In addition, a relatively small area on the posteroventral excavation was covered by independent sensory epithelium that differed from other 2 types of epithelia, and a single thin bundle derived from the posteroventral excavation comprised the most medial nerve that joins the anterior end of the olfactory nerve tract. These findings suggested that the posteroventral excavation identified herein transfers stimuli through an independent circuit and plays different roles when odorants arise from other nasal regions.

中文翻译：

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绿海龟的鼻腔包含3个独立的感觉上皮细胞。

鼻腔的形态和组织学特征在动物物种之间是不同的，陆生和半水龟的鼻腔具有两个区域，每个区域都排列有不同类型的感觉上皮。海龟可以高灵敏度地吸入挥发性和水溶性增香剂，但是海龟鼻腔内的建筑特征和感觉上皮的分布细节仍然不确定。本研究使用形态学，计算机断层扫描和组织学方法分析了绿海龟的鼻腔。我们发现，海龟鼻腔的中部区域分为前角憩室，前腹和后腹憩室，以及由含有软骨的结缔组织进行后腹开挖。后嗅憩室衬有薄薄的感觉上皮，而前嗅憩室和前腹憩室被单个厚的感觉上皮占据。此外，后腹腔的相对较小区域被独立于其他两种上皮的感觉上皮所覆盖，并且后腹腔的单个细束构成了连接嗅神经前端的最内侧神经道。这些发现表明，本文确定的后腹发掘通过一个独立的回路转移刺激，并且当来自其他鼻部区域的气味产生时起不同的作用。后腹腔开挖中相对较小的区域被独立于其他两种上皮的感觉上皮所覆盖，并且从后腹腔开挖得到的单个细束包括连接嗅神经束前端的最内侧神经。这些发现表明，本文确定的后腹发掘通过一个独立的回路转移刺激，并且当来自其他鼻部区域的气味产生时起不同的作用。后腹腔开挖中相对较小的区域被独立于其他两种上皮的感觉上皮所覆盖，并且从后腹腔开挖得到的单个细束包括连接嗅神经束前端的最内侧神经。这些发现表明，本文确定的后腹发掘通过一个独立的回路转移刺激，并且当来自其他鼻部区域的气味产生时起不同的作用。