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.
(A) Schematic of the cartilaginous framework of the upper respiratory tract. Note the intricate and precise 3-dimensional configuration of the cartilaginous structures. (B) Schematic representation of the embryonic stages of development of the upper respiratory tract.
