美洲大蠊消化系统形态学观察

MORPHOLOGY OF THE DIGESTIVE SYSTEM IN PERIPLANETA AMERICANA

为探讨美洲大蠊(Periplaneta americana)消化系统结构,通过连续石蜡切片和HE染色技术制备并观察美洲大蠊切片。结果显示,美洲大蠊消化道占据体腔大部分空间,其中前肠长度约占整个消化道长度的一半,肠壁薄,前胃中含有高度硬化的齿,便于磨碎食物;中肠是美洲大蠊消化吸收的主要部位,肠壁细胞包括单层柱状上皮细胞和再生细胞;后肠包括回肠、结肠和直肠3部分。回肠肌肉层较厚,经过回肠瓣后成为结肠。直肠肠壁细胞特化为长形垫状突起,突出于肠腔中形成直肠垫。本文为进一步阐明蟑螂结构与消化机制和变应原理论基础提供依据。

The digestive system of Periplaneta americana was detected by light microscopy. The system consists of a foregut, a midgut and a hindgut. Both foregut and hindgut are ectodermal. The length of foregut is half of the whole length of digestive system. The muscular and thick-walled proventriculus has sclerotized teeth, which is responsible for mechanical digestion. The midgut is the main region of chemical digestion and absorption. The first region of hindgut is the short, narrow, muscular ileum, and then it dilates to become the colon, the ileocolic valve marks the transition. The colon extends posteriorly to form the rectum. The wall of the rectum bears six rectal pads.