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.
Regional deposition fractions in mice lung of inhaled particles via nasal breathing. Upper respiratory tract (URT): from nasal openings to the beginning of the trachea. Tracheo-bronchial region (TB): trachea, bronchi and bronchioles. Pulmonary region (PUL): alveolar ducts and sacs. DFtot = URT + TB + PUL.
