The Bearing of Filter Feeding on the Water Pumping Mechanism of Xenopus Tadpoles (Anura: Pipidae)
The Bearing of Filter Feeding on the Water Pumping Mechanism of Xenopus Tadpoles (Anura: Pipidae)
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滤食对爪蟾蝌蚪抽水机制的影响
DOI：
10.1111/j.1463-6395.1975.tb00087.x
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发表时间：
1975
期刊：
影响因子：
1.2
通讯作者：
N. Gradwell
中科院分区：
文献类型：
--
作者：
N. Gradwell
滤食的功能解剖学的新发现使人们对水在袋鼠体内的流动有了一些了解。背侧膜器从颊咽顶向下突出，由中线两侧的三个粘膜垫和三个叶片组成。至少有四种功能可归因于背侧膜器。1.每个衬垫及其辅助叶片都安装在三个双边滤腔的每个腔内，以使呼出的水在通过咽裂流出之前必须在滤板上以薄片形式流动。2.就像水翼一样，叶片使水偏转，防止强流破坏粘液食物绳。3.当蝌蚪停止抽水时，滤腔中的背角器的堵塞作用有助于咽裂的闭塞。4.背膜腺的分泌物，特别是膜垫表面的分泌物，可能有助于腹膜的粘液包裹悬浮的食物。
其他发现涉及M3b肌，它在呼气时帮助抬高颊咽底；缺乏纤毛，但腹膜上存在低腺隆起；咽裂2和3的出口减少到由B2B和B2C肌肉控制的单一瓣膜出口；口腔触须可能缺乏机械进食功能。
New findings on the functional anatomy of filter feeding have permitted some clarification of water flow through tadopoles. The dorsal velar apparatus projects downward from the roof of the buccopharynx and consists of three mucosal pads and three vanes on both sides of the midline. At least four functions may be ascribed to the dorsal velar apparatus. 1. Each pad and its complementary vane fit so flush into each of the three bilateral filter cavities that exhalent water must flow in thin sheets over the filter plates before its exit via the pharyngeal clefts. 2. Like hydrofoils, the vanes deflect water and prevent strong currents from disorganizing the mucous food cords. 3. When tadpoles cease water pumping, the plugging effect of the dorsal velar apparatus in the filter cavities helps to occlude the pharyngeal clefts. 4. Secretions of dorsal velar glands, especially on the surface of the velar pads, may assist the mucus of the ventral velum to entrap suspended food.
Other findings concern the M3b muscle, which helps to elevate the buccopharyngeal floor during expiration; the lack of cilia, but presence of low glandular elevations on the ventral velum; the reduction of the exits from the pharyngeal clefts 2 and 3 into a single valvular exit controlled by the B2b and B2c muscles; and the probable absence of a mechanical feeding function for the oral tentacles.