The distribution of type I and type II cells in the cristae ampullaris of the guinea pig.

The sensory epithelium of the crista ampullaris can be divided both structurally and as regards sensitivity to noxious agents into a central and a peripheral zone. The question is, whether this differentiation is also reflected in the distribution of the two types of sensory cells. The present electron microscopic study, based on morphometric investigations of longitudinal and transverse sections through the crista, shows that in the guinea pig, the relative distribution of the two cell types is uniform throughout the sensory epithelium. There are about 60% type I and about 40% type II cells in both the central and peripheral areas of the crista.