Research Article

Three-Dimensional Structure and Disposition of the Air Conducting and Gas Exchange Conduits of the Avian Lung: The Domestic Duck (Cairina moschata)

Figure 3

Macrographs of fixed left lung specimens with the mesobronchus opened to show the various categories of secondary bronchi. (a) The white arrows show the openings of MV at the anterior part of the mesobronchus (MB) and just behind the extrapulmonary primary bronchus (EPB). Black arrows indicate laterodorsal secondary bronchi (LD) and the arrowheads point to PO. (b) A close-up of the internal aspect of the mesobronchus showing the openings to the lateroventral (LV) bronchi (white arrows), on the lateral aspect and opposite those of the LD (black arrows). The dark arrowheads denote the openings to the very numerous posterior secondary bronchi (POs) while the white arrowhead points to the cranial direction.
621982.fig.003a
(a)
621982.fig.003b
(b)