Anatomy of Nasal Septum

Anatomy of the Nasal Septum

In this post, we'll be exploring the nasal septum — its structure, parts, blood supply, and clinical relevance.

🧩 Parts of the Nasal Septum

The nasal septum is divided into three parts:

1. Collumellar Septum

   • Formed by the medial crura of the alar cartilages.

   • United by fibrous tissue and covered by skin.

   • Forms the columella seen externally.

2. Membranous Septum

   • Lies between the columella and the caudal border of the septal cartilage.

   • Double layer of skin with no bony or cartilaginous support.

   • Both columellar and membranous septa are freely mobile.

3. Septum Proper

   • Osteocartilaginous framework covered with mucosa.

   • Consists of a bony part and a cartilaginous part.

🦴 Bony Part of the Septum Proper

Major Bones:

• Perpendicular plate of the ethmoid

  • Forms upper 1/3rd of the septum.

  • Articulates with:

    • Superiorly: Cribriform plate
    • Posteriorly: Sphenoid crest
    • Posteroinferiorly: Vomer
    • Anteroinferiorly: Septal cartilage

• Vomer

  • Forms the posteroinferior part of the septum.

  • Articulates via alae with the sphenoid rostrum, forming the vomerovaginal canals (transmit pharyngeal branches of maxillary artery).

  • Inferior border articulates with the nasal crest (formed by maxilla and palatine bones).

  • Posterior free edge contributes to the posterior nasal septum.

Minor Contributions:

• Crest of nasal bone

• Nasal spine of frontal bone

• Rostrum of sphenoid

• Crests of palatine and maxillary bones

• Anterior nasal spine of maxilla

🧊 Cartilaginous Part of the Septum

• Septal (Quadrilateral) Cartilage

  • Main cartilage of the septum.

  • Firmly bound by collagen to surrounding bones.

  • Continuous with:

    • Upper lateral cartilages at the dorsum
    • Sphenoidal process (septal tail): projects posteriorly between vomer and perpendicular plate of ethmoid.

  • Inferiorly rests on nasal crest with pseudoarthrosis (loose connective tissue attachment).

What is the surgical importance of Septal Cartilage?

What is Nasal Septal Swell Body?

🩸 Arterial Supply of the Nasal Septum

From Internal Carotid:

• Anterior Ethmoidal Artery – Anterosuperior septum

• Posterior Ethmoidal Artery – Posterosuperior septum

From External Carotid:

• Sphenopalatine Artery (via Posterior Septal Branch) – Posteroinferior septum

• Greater Palatine Artery – Anteroinferior septum (via incisive canal)

• Superior Labial Artery (Facial artery) – Caudal septum and columella

What is Little's Area (Kiesselbach's Plexus)? What are the arteries forming it? What is it's clinical importance?

🩸 Venous Drainage of Nasal Septum

• Posterior drainage: via sphenopalatine vein to pterygoid venous plexus

• Anterior drainage: via facial vein

• Superior drainage: via ethmoidal veins to superior ophthalmic vein

• Intracranial connections: via foramen cecum to superior sagittal sinus

🔍 Retrocolumellar Vein:

• Runs vertically behind columella.

• Drains into lateral nasal wall venous plexus.

What is the most common cause of bleeding in adults?

📝 Summary Table