十一种无尾两栖类物种皮肤和肺显微结构

无尾两栖类动物的呼吸方式为肺呼吸和皮肤辅助呼吸,为探究两种呼吸器官的显微结构,本文采用解剖学和组织学的方法,对大蹼铃蟾(Bombina maxima)、腺角蟾(Megophrys glandulosa)、中华蟾蜍(Bufo gargarizans)、华西雨蛙(Hyla gongshanensis)、昭觉林蛙(Rana chaochiaoensis)、滇蛙(Dianrana pleuraden)、双团棘胸蛙(Gynandropaa yunnanensis)、贡山树蛙(Rhacophorus gongshanensis)、斑腿泛树蛙(Polypedates megacephalus)、饰纹姬蛙(Microhyla fissipes)、多疣狭口蛙(Kaloula verrucosa)的皮肤和肺的形态及显微结构进行观察。结果显示,背部和腹部皮下可见血管交错成网状,皮肤由表皮层和真皮层构成。除华西雨蛙外,其余10种均有分布于真皮疏松层与致密层间的钙化层;色素细胞位于疏松层上层,体背色素层较发达。肺囊状,中空密布血管,分为大小相当的左右肺叶,两肺叶相通并与心粘连,无气管和支气管。肺由肺囊壁、隔膜、毛细血管、肺泡细胞等结构组成。肺囊壁分为胸膜层、中间层和内层:胸膜层由扁平细胞构成,中间层由结缔组织构成,内层由肺细胞和毛细血管组成,隔膜由毛细血管和结缔组织构成,游离隔膜向中部靠拢可形成半封闭腔室,结合隔膜与肺囊壁形成封闭小腔室。在这11个物种中,肺较发达的个体,其皮肤结构中黏液腺的数量就会相对较少,组织形态学特征表现出与环境适应性关系较大,而受到系统发育关系影响较小。

Histological Observation of Skins and Lungs in Eleven Anuran Species

We used light microscope to observe the histological characteristics of the dorsal, ventral skins and lungs of Bombina maxima, Megophrys glandulosa, Bufo gargarizans, Hyla gongshanensis, Rana chaochiaoensis, Dianrana pleuraden, Gynandropaa yunnanensis, Rhacophorus gongshanensis, Polypedates megacephalus, Microhyla fissipes, Kaloula verrucosa (Table 1). The results showed that the blood vessels in the back and the abdomen were interlaced into reticular veins. The morphological characteristics of dorsal skins, abdominal skins and lungs of these species were different (Table 2). The skin consisted of the epidermis and dermis (Table 3). Except for Hyla gongshanensis, the remaining 10 species had lamina calcarea distributed between the stratum spongiosum and stratum compactum of the dermis (Fig. 1). The pigment cells were located in the stratum spongiosum, with the dorsal pigment layer more developed. The alveolar sac, shaped hollow with dense blood vessels (Fig. 3), were divided into the right and left lobules of the same size. The lung was composed of pulmonary cyst wall, septum (Table 4), capillary and pulmonary alveoli. The pulmonary cyst wall consisted of the pleural layer, the middle layer and the inner layer: the pleural layer was composed of flat cells; the middle layer was composed of connective tissue; the inner layer was composed of pulmonary alveoli and capillaries; and the septum was composed of capillaries and connective tissues (Fig. 4). In these 11 species, individuals with more developed lungs tended to have reduced mucous glands in the skin structure. Individuals with more developed lungs had reduced mucous glands in their skin structure, and their histological features showed greater adaptation to the environment and less influence from phylogenetic relationships.