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.
Variability of lung epithelial composition in the tracheobronchial tree. The relative abundance of ciliated, secretory goblet and club cells, as well as basal cells changes as a function of airway branching level and diameter. Cell percentage values estimated from Crystal et al. [18] and Mercer et al. [19]. (Online version in colour.)
