External framework

The external nose framework is part bone part hyaline cartilage:

The bony parts form a pear- shaped opening known as the external nasal aperture. The aperture is bounded superiorly by the two nasal bones and inferiorly plus laterally by the two maxillae.

The nasal cartilages are attached to the edge of the anterior nasal aperture to form the nares (nostrils). The lateral boundary of the nares is formed by fibrofatty tissue posteriorly and the major alar cartilage anteriorly. In the midline, the alar cartilages turn inwards to form the medial boundary of the aperture below the nasal septum.

Internal framework

Several structures contribute to the nasal cavity:

• The nasal septum divides the cavity into left and right halves, being formed superiorly by the perpendicular plate of the ethmoid, posteriorly by the vomer and anteriorly by cartilage.
• The cavity roof is arched and bounded anteriorly by the nasal bones, superiorly by the cribriform plate of the ethmoid, and posteriorly by the inferior surface of the body of the sphenoid. Olfactory nerves pass through the cribriform plate to the olfactory bulb.
• The floor consists of the palatine processes of the maxillae anteriorly, and the horizontal plates of the palatine bones posteriorly.
• Each lateral wall is formed mainly by the maxilla and three conchae. While the superior and middle conchae are part of the ethmoid, the inferior concha is its own separate bone.