Nasal septal cartilage

At a glance

English

Nasal septal cartilage

Latin (TA2)

Cartilago septi nasi

System

Cartilage

Region

Head

Side

Single, on the midline

About the nasal septal cartilage

The septal cartilage is the flexible front part of the wall that divides the nose into right and left cavities. It is a flat plate of hyaline cartilage with four sides, set in the midline and covered on each face by the mucous membrane of the nasal cavity. Behind and above it the septum is completed by bone: the ethmoid's perpendicular plate above and behind, and the vomer below and behind. The cartilage fits into the angle between these two bones, and its lower border also rests in a groove along the nasal crest of the maxilla.

Each edge has its own neighbour. The posterior-superior border joins the ethmoid plate, and the posterior-inferior border joins the vomer and the anterior nasal spine. The front, dorsal border lies under the bridge of the nose; in its upper part it is attached to the internasal suture between the nasal bones and widens into the paired upper lateral cartilages, while lower down it is free. The lowest, caudal edge sits between the medial crura of the major alar cartilages and is linked to them by fibrous tissue in the membranous septum. A thin strip of cartilage, the posterior or sphenoidal process, may extend back between ethmoid and vomer.

Because it is the midline support of the external nose, the septal cartilage largely fixes the nose's straightness and the height of the lower bridge. Together with the alar and upper lateral cartilages it keeps the airway open, and dividing the inflow into two narrow streams helps warm, moisten and direct the air. Its own blood supply comes from the overlying lining through the perichondrium, which is why the cartilage depends on that covering to survive.

A septum that deviates to one side is common and often causes no trouble, but a marked bend can block one or both sides, make breathing harder and favour sinus infection; the nose may also look crooked. Septoplasty straightens it by trimming or repositioning parts of the cartilage, and recovery takes some months. A blood clot under the perichondrium after a blow (septal haematoma) must be drained quickly, or the cartilage may break down and the bridge sag.

Attachments and function

Attaches from

Its posterior borders are joined to the ethmoid's perpendicular plate, the vomer and the nasal crest of the maxilla.

Attaches to

Its dorsal border attaches to the nasal bones and continues as the upper lateral cartilages; its caudal border is linked by fibrous tissue to the medial crura of the major alar cartilages.

Function

Separates the two nasal cavities in front, supports the bridge and tip of the external nose and helps keep the nasal airway open.

Nerve supply

The covering mucosa is supplied by the nasopalatine nerve and the internal nasal branches of the anterior ethmoidal nerve.

Blood supply

The cartilage has no vessels of its own and is fed from the perichondrium and mucosa, supplied by the sphenopalatine, anterior ethmoidal, greater palatine and superior labial arteries, which meet at the front of the septum.