Fig. 1.
Model of alveolar duct showing three alveolar duct units. The outer walls of the alveoli in the top right quadrant have been made transparent for clarity. See Geometric model of alveolar ducts for details.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.