Figure 7-3. Supra laryngeal structures.
The (external) nose is the beginning of the respiratory system in humans. It is
located in the center of the front of the face. It is pyramid shaped, with the base facing
inferiorly. The base consists of two openings called the nares or nostrils. These open
into a pair of vestibules, one on each side. The nares are guarded by stiff nasal hairs.
These nasal hairs serve to remove the larger particles (such as lint and cinders) from
the inflowing air.
7-22. NASAL CHAMBERS
The vestibules of the nose are continuous posteriorly with the right and left nasal
a. Nasal Septum. Like the vestibules, the nasal chambers are separated by a
nasal septum, a vertical wall from front to back. Constructed of bone and cartilage, the
nasal septum extends from the floor to the roof and from front to back.
b. Mucoperiosteal Lining. Each nasal chamber is lined with a mucoperiosteal
lining. This mucoperiosteal lining is a special combination of tissues, which are rich in
blood vessels. This excellent supply of blood furnishes moisture and heat. On the
surface of the mucoperiosteum are minute hair-like processes called cilia. The cilia
continuously drive fluids on the surface to the rear. A part of the fluids secreted on the
surface is a mucous material. As a part of the continuous process of cleansing the
inflowing air, finer particles are trapped by the mucus.
c. Conchae. Thus, the conditioning of the inflowing air depends upon direct
contact with the mucoperiosteum. The greater the surface area, the more efficient will