A Morphological Investigation of the Postnatal Development of the Syrinx in the Quail


Abstract: The morphological and structural development of the syrinx was studied with a light microscope in 100 female and male Japanese quails from 1 to 60 days old and adults. The quails had a tracheobronchial syrinx since it was based on both tracheal and bronchial elements. Two tracheal syringeal cartilages were attached at both ends to the pessulus in the tympanum. In this species the tympanum had a slightly increased diameter. The pessulus was a wedge-shaped cartilage, its blade lying dorsoventrally so that it divided the airway vertically. The pessulus examined histologically at 35 and 42 days post-hatching showed marked and uneven basophilia of the matrix in males and females, respectively. The chondrocytes showed varying degrees of degeneration. The marrow foci were encountered but no bone tissue was recognized. In the adults bone was present while at 60 days post-hatching it was absent. The basis of the divided part of the syrinx which was C-shaped was formed by bronchial syringeal cartilages. The first bronchial syringeal cartilage was attached at both ends to the pessulus. The external or lateral tympaniform membranes were present on each side of the syrinx. The internal or medial tympaniform membranes were present on the medial wall of the bronchus on either side of and behind the pessulus. The lateral and medial tympaniform membranes were covered by stratified cuboidal epithelium post-hatching which showed different regional features. The epithelium of the medial membranes had more layers of cells than that covering the lateral membranes. The total thickness of the medial membranes was more than that of the lateral membranes.

Keywords: Quail, Syrinx Membrana tympaniformis lateralis, Membrana tympaniformis medialis, Pessulus.

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