Comparative Histology and Micrometric Analysis of Pharyngeal cavity in Egyptian Laughing Dove (Streptopelia senegalensis aegyptiaca) and Japanese Quail (Coturnix coturnix japonicum)

Abstract

Birds of different families; Japanese Quail (family Phasianidae) and Laughing Dove (family Columbidae) were used for this study to focus on the histological and micrometric comparison of the pharyngeal roof and floor with its content. The thickness of the lining epithelium of the pharyngeal roof, root of the tongue was almost equal in both species, whereas of the laryngeal mound of quail was nearly 5 times thicker than that of dove. On the other hand, the diameter of the glandular lobules of all studied salivary glands in the pharyngeal cavity of quail was more than that of dove except caudal lingual salivary glands. The entrance of the infundibular cavity of dove was infiltrated by aggregations of lymphoid tissue, but there were variably sized lymph nodules in quail termed pharyngeal nodules. The sphenopterygoid salivary glands (branched tubular mucous type) of dove were fewer than those of quail. The caudal lingual salivary glands were concentrated centrally dorsal to basihyoid of the hyoid bone in dove but distributed dorsolaterally to the basihyoid in quail. The lamina propria of the laryngeal mound of dove had 2 groups of circopterygoid salivary glands (rostromedial and caudomedial), lining by tall columnar epithelium, while of quail had 3 groups (rostromedial, rostrolateral and caudomedial) circopterygoid salivary glands, lining by low columnar epithelium. The laryngeal mound of both species was supported by two groups of intrinsic laryngeal muscles and 3groups of extrinsic laryngeal muscles.