Angioarchitectural form, functional distributive pattern and classification of the fungiform papillae on the crossbred Japanese cat tongue anterodorsal surface in scanning electron microscopic specimens.

The purpose of this study was to undertake a three-dimensional comparative observation of the angioarchitectural form, functional distributive pattern, and to classify the fungiform papillae (FuP) found sporadically and geometrically on the oblique lines of the filiform papillae (FiP) on the entire dorsal surface of the crossbred Japanese cat foretongue in microvascular cast specimens (MVCS). By means of the corrosive resin casting technique, the MVCS of the FuP of the cat tongue were prepared and examined in detail under the scanning electron microscope (SEM). With regard to the arrangement of FiPs and FuPs on the frontal half of the antero-dorsal surface of the cat foretongue, FiP types I-V and FuP types I-IV are arranged a A form with the point in the direction of the apex and in an oblique line running from the antero-central portion to both postero-peripheral portions. In the rear half of the antero-dorsal surface of the foretongue, FiP types I-V and types FuP I-IV are arranged in a V form with the point in the direction of the radix and in an oblique line running from both antero-peripheral portions to the postero-median portion or towards the pharynx on the anterior centro-dorsal surface of the cat foretongue. With the FuP arranged in the medial zone (M) and peripheral zone (P) running from the central to the apical parts, both the peripheral parts and the pharyngeal can be classified into four types (FuP types I-IV) according to the shape and size of the main process (MP), the number of the accessory processes (AP) and the regional position of the lozenge arrangement. FuP Types I-III consisted of a MP containing a large half oval, network-like process, and the AP contained a bundle of spine-like processes arranged radially in a circle at the anterior basal margin of the MP. The FuP Type IV was made up of only one MP. In the central zone (C) of a lozenge part arranged in the A and V forms, there was no FuP as a taste organ. It was assumed that in the lozenge arrangement of the A and V forms, except for the C zone, FuPs could be classified into four types (FuP types I-IV) from the frontal portion of the antero-dorsal surface toward the pharynx on the foretongue, and would play an assistant functional role in receiving the sense of taste of foods and liquids.