Igbokwe Casmir O, Mbajiorgu Felix E
School of Anatomical Sciences, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
Department of Veterinary Anatomy, University of Nigeria, Nsukka, Nigeria.
Anat Histol Embryol. 2019 Sep;48(5):455-465. doi: 10.1111/ahe.12467. Epub 2019 Jul 26.
The African giant pouched rat is a nocturnal, fossorial and omnivorous wild rodent widely distributed in sub-Saharan Africa. The morphology of lingual surface has not previously examined and was investigated by gross dissection, stereomicroscopy, scanning electron and light microscopy. Grossly, it was elongated and dorso-ventrally flattened with rounded tip. It measured 3.48 ± 0.33 cm in length, with a median groove of 1.4 ± 0.1 cm in length and well-developed lingual prominence. Stereomicroscopically, filiform, fungiform and vallate papillae were indicated in the apex, body and root. Fungiform papillae intermingled with filiform on the ventral and dorsal surface of the apex and body. Three vallate papillae were located in triangular arrangement on the root. The surface ultrastructural features distinguished four types of filiform which varied in size, shape and distribution: first type with long pointed process was preponderant on the apex and body of tongue; the second with robust base was located on central lingual prominence; the third (caudal body) was conically shaped with pointed process; and the fourth type (root) had forked filamentous process. Large oval-shaped fungiform papillae were apparent. Each vallate was surrounded by a circumferential groove into which taste pores opened. Histologically, the tongue surface displayed moderately keratinized stratified squamous epithelium, and lamina propria that varied in places. Fungiform and vallate showed spindle-shaped taste buds. Serous and mucous acini containing neutral and acidic mucins were observed in lamina propria of root. The structural adaptations of the tongue to omnivorous diet and food manipulation in oral cavity were comparatively discussed.
非洲巨囊鼠是一种夜行性、穴居性且食性多样的野生啮齿动物，广泛分布于撒哈拉以南非洲地区。此前尚未对其舌面形态进行过研究，本研究通过大体解剖、体视显微镜、扫描电子显微镜和光学显微镜对其进行了调查。大体上，它呈细长形，背腹扁平，尖端圆润。其长度为3.48±0.33厘米，中间沟长1.4±0.1厘米，舌隆突发育良好。在体视显微镜下，丝状乳头、菌状乳头和轮廓乳头分别见于舌尖、舌体和舌根。菌状乳头在舌尖和舌体的腹面和背面与丝状乳头相互交织。三个轮廓乳头呈三角形排列于舌根。表面超微结构特征区分出四种丝状乳头，它们在大小、形状和分布上各不相同：第一种具有长而尖的突起，在舌尖和舌体上占优势；第二种基部粗壮，位于舌中央隆突；第三种（舌体尾部）呈圆锥形，有尖突；第四种（舌根）有叉状丝状突起。大型椭圆形菌状乳头明显可见。每个轮廓乳头被一个圆周沟包围，味孔开口于此。组织学上，舌表面显示为中度角化的复层鳞状上皮，固有层各处有所不同。菌状乳头和轮廓乳头显示出纺锤形味蕾。在舌根固有层中观察到含有中性和酸性粘蛋白的浆液性腺泡和粘液性腺泡。本文对舌在杂食性饮食和口腔食物处理方面的结构适应性进行了比较讨论。
