serial-sectioning of the alveoli , and the creation of montages of the entire circumference of each alveolus at intervals of every twentieth section ( approximately 1.6 micron ) at a magnification of x 2,160 permitted precise identification of cells and connective tissue gaps and allowed the reconstruction , by computer techniques , of the alveolar walls in 3 dimensions .
C1515933
alveoli
C0225695
alveolar walls