カエルの鼓膜とその周辺
1988 年 19 巻 1 号 p. 83-85
詳細
1988 年 19 巻 1 号 p. 83-85
The tympanic membrane of frog is exposed directoly to the external environment. It is almost round in shape, and is thickened in the central part. Circumferential part is thinner than central part. The tympanic mebrane was uniformly spread along the outer edge of the annular cartilage, and no pars flaccida was observed. Fibrous tissue of the lamina propria consist of radial collagen fiber. The tip of the columella consists of cartilage, loosely adhered to the dorsal surfase of the center of tympanic membrane. Along the columella, there was a loose, wrinkly connective tissue between the tympanic membrane and columella, that is the archetype of malleus handle. The annular cartillage was considered to be the original form of the external auditory canal.
