Microscopic and submicroscopic anatomy of the parabronchi, air sacs, and respiratory space of the budgerigar (Melopsittacus undulatus).

摘要: The normal microscopic and submicroscopic structure of the lower respiratory tract budgerigar (Melopsittacus undulatus) is described compared with other birds mammals. Granular (type II) pneumocytes are confined to linings air sacs, parabronchi, their atria; however, secretions (surfactant) cover surfaces infundibula space. Infundibula extend from atria give rise capillaries, which branch anastomose freely those adjacent parabronchi (interparabronchial septa not found). labyrinth lined by a continuous epithelium squamous pneumocytes, whose perikarya concentrated in peripheral cytoplasm markedly attenuated. share basal lamina blood capillaries that they envelop.