Supralaryngeal structures are shown in figure 1-2.
a. External Nose. The external nose is the portion projecting from the face. It
is supported primarily by cartilages. It has a midline divider, called the nasal septum,
which extends from the internal nose. There are paired openings (nostrils) that lead to
paired spaces (vestibules). Guard hairs in the nostrils filter inflowing air.
b. Nasal Chambers (Internal Nose). Behind each vestibule of the external
nose is a nasal chamber. The two nasal chambers together form the internal nose.
These chambers, too, are separated by the nasal septum.
(1) The walls of the nasal chambers are lined with a thick mucous-type
membrane known as the mucoperiosteum. It has a ciliated (hair-like projection that
move fluids to the rear) epithelial surface. It also has a rich blood supply that provides
warmth and moisture. At times, the membrane may become quite swollen.
(2) The lateral wall of each chamber has three scroll-like extensions into the
nasal chamber that help to increase the surface area exposed to the inflowing air.
These scroll-like extensions are known as conchae.
Figure 1-2. Supralaryngeal structures.