CorpusHuman Anatomy
RespiratoryOrgan part

Nasal septum

Septum nasi

The midline partition dividing the nasal cavity into right and left halves, made of bone posteriorly and cartilage anteriorly.

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Overview

The septum is formed by the perpendicular plate of the ethmoid (posterosuperiorly), the vomer (posteroinferiorly) and the septal cartilage (anteriorly), with small contributions from the nasal crests of the maxillae and palatine bones. It is covered by respiratory mucosa except in its upper part, where olfactory epithelium is found.

The anterior septum carries Kiesselbach's plexus (Little's area), the source of most nosebleeds. Mild deviation is almost universal; significant deviation can obstruct one side, impair sinus drainage and is corrected by septoplasty.

Location

Midline of the nasal cavity, from the nasal bones and cribriform plate above to the hard palate below.

Parts & subdivisions

  1. Perpendicular plate of ethmoid
    Thin bony plate descending from the cribriform plate.
  2. Vomer
    Plough-shaped bone forming the posteroinferior septum and the medial border of each choana.
  3. Septal cartilage
    Hyaline cartilage forming the anterior septum; nourished by the overlying perichondrium.
  4. Kiesselbach's plexus (Little's area)
    Arterial anastomosis on the anteroinferior septum: anterior ethmoidal, sphenopalatine, greater palatine and septal branch of the superior labial arteries.

Anatomy

Innervation

Nasopalatine nerve (CN V2) and anterior ethmoidal nerve (CN V1); olfactory fibres in the upper part.

Arterial supply

Sphenopalatine (via posterior septal branches), anterior and posterior ethmoidal, greater palatine and superior labial arteries.

Function

  • Divides the nasal airway into two passages, supporting the nasal cycle.
  • Supports the dorsum and tip of the external nose.

Clinical significance

Septal haematoma

Blood collecting between cartilage and perichondrium deprives the cartilage of its blood supply; untreated it causes necrosis, abscess and saddle-nose deformity. It requires urgent incision and drainage.

Septal perforation

Causes include previous surgery, cocaine use, granulomatosis with polyangiitis and nose picking; may cause whistling and crusting.

Compiled from standard anatomy and physiology references — see the Respiratory System sources. For education only; not medical advice.