Nasal Septum

1. Overview

The nasal septum is the vertical partition that divides the nasal cavity into right and left halves. It plays a crucial role in maintaining proper airflow, supporting the structure of the nose, and facilitating respiration. Made of both bone and cartilage, the nasal septum ensures laminar airflow and supports the function of adjacent nasal structures including the turbinates, meatuses, and sinuses.

2. Location

The nasal septum is located in the midline of the nasal cavity, extending from the external nares (nostrils) to the posterior choanae. It separates the two nasal passages and forms the medial wall of each nasal chamber. Its superior edge articulates with the floor of the anterior cranial fossa, while the inferior margin rests on the hard palate.

3. Structure

The nasal septum consists of three primary components:

Cartilaginous Part

• Formed by the septal cartilage, flexible and anterior

• Provides support to the nasal dorsum and tip

Bony Part

• Perpendicular plate of the ethmoid bone: Forms the superior portion of the bony septum

• Vomer bone: Forms the posteroinferior part

Membranous Part

• Located just behind the nostrils, between the cartilage and skin

• Contains dense connective tissue and is mobile

Other Features

• Covered by respiratory mucosa: pseudostratified ciliated columnar epithelium with goblet cells

• Blood supply: Richly vascularized by branches of the:

  • Anterior and posterior ethmoidal arteries

  • Sphenopalatine artery

  • Superior labial artery

• Kiesselbach’s plexus: A dense vascular network on the anterior septum, common site of nosebleeds (epistaxis)

4. Function

The nasal septum serves several vital respiratory and structural functions:

• Airflow regulation: Ensures even distribution of air through both nasal passages

• Structural support: Maintains the midline structure and shape of the external nose

• Surface area optimization: Helps direct air toward the conchae and meatuses for filtration and conditioning

• Division of nasal cavity: Creates separate right and left nasal chambers for efficient airflow

5. Physiological Role(s)

The nasal septum plays additional roles beyond structural division:

• Optimizes olfaction: Guides airflow toward the olfactory epithelium near the cribriform plate

• Mucociliary function: Supports mucosal lining for humidification, warming, and trapping pathogens

• Resonance and phonation: Contributes to vocal tone by affecting nasal resonance

• Immune defense: Hosts a rich mucosal immune interface with lymphoid cells and secretory IgA

6. Clinical Significance

Deviated Nasal Septum (DNS)

A common condition where the septum is displaced from the midline, which may be congenital or result from trauma. Effects include:

• Unilateral nasal obstruction

• Snoring or sleep apnea

• Frequent sinus infections

• Nasal congestion and postnasal drip

Managed with septoplasty (surgical correction).

Epistaxis

Kiesselbach’s plexus, located on the anterior septum (Little’s area), is the most common site of nosebleeds. Causes include:

• Dry air

• Trauma (e.g., nose-picking)

• Hypertension or anticoagulant use

Initial treatment includes pressure, topical vasoconstrictors, or cauterization.

Nasal Septal Hematoma

Occurs due to trauma causing blood collection between the cartilage and mucosa. Untreated, it can lead to:

• Infection

• Cartilage necrosis

• Saddle-nose deformity

Requires prompt drainage and antibiotic therapy.

Perforated Nasal Septum

May result from trauma, surgery, infection, or inhaled drugs (e.g., cocaine). Symptoms include:

• Whistling sound when breathing

• Crusting and bleeding

• Nasal obstruction

Small perforations may heal; larger ones may need surgical repair or silicone button placement.

Septal Deformity in Facial Development

In children, septal deviation can influence midfacial growth. Early correction may prevent long-term cosmetic and functional issues.