Cartilages of the Nose - Complete Overview

Vertical thirds of the nose (Murray & Nadel's Textbook of Respiratory Medicine)

Summary Table

1. Septal Cartilage (Quadrilateral Cartilage) - 1

• Also called the quadrangular cartilage
• Forms the cartilaginous anterior nasal septum
• Bound to the nasal bones superiorly, perpendicular plate of ethmoid posterosuperiorly, and vomer posteroinferiorly
• Continuous with both upper lateral cartilages at the nasal bridge ("keystone area")
• A posterior projection called the sphenoidal process (septal tail) extends between the vomer and the perpendicular plate

2. Upper Lateral Cartilages (ULC) - 2 (paired)

• Also called the triangular cartilages or lateral nasal cartilages
• Support the middle third of the nose
• Their cephalic edge slides under the nasal bones at the keystone area
• Their medial edges are fused with the dorsal septal cartilage (they are actually continuous with the septal cartilage superiorly and only become separate structures inferiorly)
• The angle between the ULC and septum forms the internal nasal valve (most important airway resistance point in the nose)

3. Lower Lateral Cartilages (LLC / Greater Alar Cartilages) - 2 (paired)

• Also called the alar cartilages or greater alar cartilages
• Define the lower third and tip of the nose
• Each has three crura:
  • Medial crus - forms the columella, attaches to caudal septal cartilage
  • Middle crus (intermediate crus) - forms the dome/nasal tip
  • Lateral crus - extends laterally to form the alar rim
• Contrary to common belief, the lower lateral cartilages do not extend to the very margins of the nostril rim

4. Sesamoid (Minor Alar / Accessory) Cartilages - Variable (2-4)

• Small fibrofatty cartilages situated lateral to the lower lateral cartilages
• Part of the "sesamoid complex" that bridges the lateral crus to the piriform aperture
• They are a minor tip support mechanism - they extend support of the lateral crura to the piriform aperture

5. Vomeronasal Cartilages (Cartilages of Jacobson) - 2 (paired)

• Narrow strips of cartilage located between the inferior edge of the septal cartilage and the vomer
• Embryological remnants of the vomeronasal organs (Jacobson's organs), which regress before birth
• Often found in association with a septal spur
• Can be used as graft material when septal/auricular cartilage is absent or exhausted

Anatomical Diagram of the Nasal Septum

Components of the nasal septum showing the septal cartilage, vomeronasal cartilage, and medial crus of alar cartilage (Scott-Brown's Otorhinolaryngology)

Key Structural Relationships (for exam purposes)

• Upper third of nose = nasal bones
• Middle third = upper lateral cartilages
• Lower third = lower lateral cartilages
• The internal nasal valve = angle between ULC and dorsal septum (primary airway resistance zone)
• The external nasal valve = formed by lower lateral cartilage + septum + inferior turbinate

• Cummings Otolaryngology Head and Neck Surgery
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery
• Murray & Nadel's Textbook of Respiratory Medicine
• K.J. Lee's Essential Otolaryngology