Ultrastructure of the tongue and histochemical features of the lingual salivary glands in buzzards

Abstract

The macroscopic characteristics of the tongues of 8 long-legged buzzards are described and scanning electron microscopy wasused to examine the epithelial tissue of the tongue’s surface. Crossman’s modified triple staining method and hematoxylin and eosin dyewere used to determine the locations and general histological features of the lingual salivary glands. The nature of the glandular secretionswas examined by staining with PAS, AB pH 1.0, AB pH 2.5, and PAS-AB pH 1.0 and pH 2.5, and diastase enzyme digestion. PAS stainingand weak, moderate, and strong methylation procedures as well as sialidase and hyaluronidase applications were performed. We reportthe finding of focal accumulations of the anterior lingual salivary glands at the tongue’s base with numerous duct openings in this area.This finding, in conjunction with the absence of taste papillae in the tongue epithelium, suggests that the role of the tongue in buzzardsis to mix food with saliva and to move the food bolus rapidly to the back of the oral cavity. The acidic secretions of the lingual salivaryglands not only have antimicrobial effects but also facilitate the swallowing process and may influence the digestive process in the distalparts of the alimentary tract.