Fig. 7.

Vascular remodeling of the alveolar vascular ring. a Microvascular corrosion casts and SEM of vascular rings at the alveolar opening depict the incidence of remodeling due to intussusceptive angiogenesis. b The appearance of transluminal pillars on the interconnections between the alveolar entry rings indicates the occurrence of intussusceptive angiogenesis at the site of the alveolar opening. Bar = 15 um. c Elongation of such transluminal pillars results in a vessel duplication of ring blood vessels. Bar = 15 um. d High-resolution Synchrotron radiation tomographic microscopy demonstrates a vascular duplication (red arrowheads). Bar = 20 μm