Nagato T, Nagaki M, Murakami M, Tanioka H
Okajimas Folia Anat Jpn. 1989 Oct;66(4):195-209. doi: 10.2535/ofaj1936.66.4_195.
In an attempt to elucidate the functions of three types of filiform papillae in the rat's tongue, corrosive resin casts of the microvessels in the filiform papillae were observed under the scanning electron microscope. The filiform papillae were also examined by light and transmission electron microscopy. The three dimensional architecture of the microvessel loops in the small conical filiform papillae was relatively simple with limited divergence and anastomosis in the papillae, whereas that in the large conical filiform papillae formed a complex network which resulted from repeated divergence and anastomosis. The microvessels in the thready filiform papillae branched several times in the primary papillae and then formed a hairpin-like loop in each of the secondary papillae. Under the light and transmission electron microscope, the small and large conical filiform papillae revealed remarkably similar tissue architectures, with the exception of their sizes. However, these two types of filiform papillae were arranged in quite opposite directions. In the large conical filiform papillae, the epithelium on the anterior side of the papillae lacked a granular layer, whereas the epithelium on the posterior side contained a well-developed granular layer. Based on these findings, we presume that the functions of the three type of filiform papillae are as follows. That of the small conical filiform papillae is to take food efficiently into the oral cavity. That of the large conical filiform papillae is to grind further the food which has been crushed with the teeth in coordination with the palate. The thready filiform papillae might function as a heat-releasing organ and be involved in the control of body temperature.
为了阐明大鼠舌头上三种丝状乳头的功能，在扫描电子显微镜下观察了丝状乳头中微血管的腐蚀性树脂铸型。还通过光学显微镜和透射电子显微镜对丝状乳头进行了检查。小圆锥形丝状乳头中微血管环的三维结构相对简单，乳头内的分支和吻合有限，而大圆锥形丝状乳头中的微血管环则形成了一个复杂的网络，这是由反复的分支和吻合造成的。丝状丝状乳头中的微血管在初级乳头中分支几次，然后在每个次级乳头中形成一个发夹状环。在光学显微镜和透射电子显微镜下，小圆锥形丝状乳头和大圆锥形丝状乳头除大小外，组织结构非常相似。然而，这两种丝状乳头的排列方向却完全相反。在大圆锥形丝状乳头中，乳头前侧的上皮缺乏颗粒层，而后侧的上皮则含有发育良好的颗粒层。基于这些发现，我们推测三种丝状乳头的功能如下。小圆锥形丝状乳头的功能是有效地将食物摄入口腔。大圆锥形丝状乳头的功能是与上颚协同作用，进一步研磨已被牙齿咬碎的食物。丝状丝状乳头可能起到散热器官的作用，并参与体温的调节。
