Fig. 1.

Five right lung specimens at 7-8 weeks. Panels are shown in order from the smaller lung to the larger one. Note that a specimen with 39 mm crown-rump length (CRL) carries a lung smaller than those in specimens with 37 mm CRL. Panels (A), (D), and (E) include the middle and lower lobes, while panels (B) and (C) the lower lobe only. Star indicates an area in which the segmental bronchus VII is likely to present in the immediately anterior side of the inferior pulmonary vein (IPV). Asterisk indicates a cavity through the oval window between the right atrium (RA) and left atrium (LA). AO, aorta; B6, B8, B9, B10, segmental bronchi VI, VIII, IX, and X; B9+10, a common trunk bronchus with the segmental bronchi IX and X; ES, esophagus. All panels are prepared at the same magnification. Scale bar in panel (A)=1 mm (A-E).