Nasal septum

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Bones, cartilages and mucosa of the medial wall of the nasal cavity.

The nasal septum is the midline vertical partition which separates the nasal cavity into left and right halves, forming the medial wall of each half. It is comprised of bony and cartilaginous parts. The bony part of the septum is main formed by two bones: the perpendicular plate of the ethmoid superiorly, and the vomer inferiorly, although there are minor contributions made by the nasal, frontal, sphenoid, maxilla and palatine bones. The vomer slots into a grooved ridge on the hard palate and extends beyond the incisive canal anteriorly and is grooved on each side by the nasopalatine nerves. Superiorly the vomer articulates with the perpendicular plate of the ethmoid, but only for a short section of its upper margin at the posterior end. The perpendicular plate of the ethmoid is continuous superiorly with the cribriform plate. 

Anteriorly, between the two bones of the septum, there is a gap which is filled by a sheet of cartilage known as the septal cartilage. The septal cartilage is made of hyaline cartilage and is the unossified part of the ethmoid's perpendicular plate, which can extend quite far back between the two bones. The nasal septum is covered with a mucosal layer which moistens and warms air passing through the nasal cavity.