Angioarchitectural structure and functional distributive pattern of the filiform papillae on the meso-dorsal surface of the rabbit tongue.

The angioarchitectural classification and distributive patterns were investigated in the filiform papillae (FiP) on the meso-dorsal surface of the rabbit tongue by using microvascular cast specimens (MVCS) and the scanning electron microscope (SEM). The author examined the microvascular network structures, which consisted of ascending and descending branches entering the FiP. They inclined in a posterior (pharynx) direction, and densely and geometrically covered the meso-dorsal surface, directing the spoon-like concave face in an anterior direction. FiPs could be classified into three types: a small filiform papilla (SfP) covering on the meso-dorsal surface except for the marginal part of the intermolar eminence (MIME) and the intermolar eminence itself (IME): a spoon-like concave structure facing in an anterior (apex) direction with an arrowhead-like top: a middle filiform papilla (MfP) on the MIME, made up of a long triangle-like concave structure with a sharp arrowhead-like top and inclined at right angles to the IME. A large filiform papilla (LfP) on the whole swelling dorsal area of the IME was formed by a long triangle-like concave structure with a sharper arrowhead-like top. LfPs are longer and larger than MfPs and inclined towards the pharynx.