Nasal septum

The nasal septum separates the left and right airways in the nose, dividing the two nostrils.

It is depressed by the depressor septi nasi muscle.

The fleshy external end of the nasal septum is sometimes also called columella. The nasal septum contains bone and hyaline cartilage.

The nasal septum is composed of five structures:

• perpendicular plate of ethmoid bone
• vomer bone
• cartilage of the septum
• crest of the maxillary bone
• crest of the palatine bone

The medial wall or septum is frequently more or less deflected from the median plane, thus lessening the size of one nasal cavity and increasing that of the other; ridges or spurs of bone growing into one or other cavity from the septum are also sometimes present. Immediately over the incisive canal at the lower edge of the cartilage of the septum a depression, the nasopalatine recess, is seen. In the septum close to this recess a minute orifice may be discerned; it leads backward into a blind pouch, the rudimentary vomeronasal organ of Jacobson, which is supported by a strip of cartilage, the vomeronasal cartilage. This organ is well-developed in many of the lower animals, where it apparently plays a part in the sense of smell, since it is supplied by twigs of the olfactory nerve and lined by epithelium similar to that in the olfactory region of the nose.