The nasal septum is a thin, vertical structure that divides the nasal cavity into two symmetrical halves—left and right. It is made up of both bone and cartilage, providing support and shape to the nose. The bony part forms the posterior (back) section, while the cartilaginous part forms the anterior (front) section. The entire septum is lined by a mucous membrane, which helps keep it moist and protects it from dust and pathogens. It plays a structural role in the nasal passage and serves as a partition within the nasal cavity.
Where is it located?
The nasal septum is located in the midline of the nose, extending from the nostrils (external nares) at the front to the nasopharynx at the back. It separates the left and right nasal cavities, forming the central support framework for the nasal passages.
Structure
The nasal septum is a thin, vertical structure that separates the two nasal cavities. It is composed of bone, cartilage, and a mucous membrane. Here’s a detailed breakdown of its structure:
1. Bony Components
The posterior (back) part of the nasal septum is made up of bones that provide structural support:
- Perpendicular Plate of the Ethmoid Bone – Forms the upper part of the septum.
- Vomer Bone – Forms the lower and posterior portion of the septum.
- Nasal Crest of the Maxilla and Palatine Bones – Contribute to the base of the septum.
2. Cartilaginous Component
The quadrangular cartilage forms the anterior (front) portion of the septum.
- This cartilage provides flexibility and allows slight movement.
- It connects the bony part to the external nose structure, giving shape and support.
3. Soft Tissue and Mucosa
- Mucous Membrane – Covers the entire septum, keeping it moist and protecting it from dust, bacteria, and dryness.
- Blood Supply – Rich vascularization occurs through branches of the sphenopalatine artery, ethmoidal arteries, and facial artery (notably the Kiesselbach’s Plexus in the anterior septum, which is prone to nosebleeds).
- Nerve Supply – Sensory nerves are supplied by the trigeminal nerve (V1 and V2 branches).
Function
- Airflow Regulation – Ensures smooth passage of air through the nostrils.
- Support – Provides structural support to the nose.
- Olfaction (Smelling) – Helps direct airflow towards the olfactory receptors for detecting smells.
- Moisturizing and Filtering Air – Traps particles and humidifies incoming air.
Clinical Significance
The nasal septum plays a crucial role in maintaining proper airflow, filtering, and humidifying inhaled air. Its clinical significance includes:
Deviated Nasal Septum (DNS):
- A common condition where the septum is displaced to one side, leading to nasal obstruction, breathing difficulties, snoring, and sinus infections.
- Severe cases may require septoplasty surgery for correction.
Epistaxis (Nosebleeds):
- The Kiesselbach’s Plexus (Little’s Area) in the anterior septum is highly vascularized, making it a frequent site of nosebleeds.
- Causes include trauma, dryness, infections, and hypertension.
Septal Perforation:
- A hole in the septum caused by trauma, surgery, drug abuse (e.g., cocaine), or infections.
- Symptoms include whistling sounds during breathing, crusting, and nasal discharge.
Septal Hematoma:
- Blood collection between the mucosa and cartilage, often due to nasal trauma.
- It can lead to abscess formation, cartilage damage, or nasal deformities if untreated.
Nasal Polyps and Sinusitis:
A deviated septum may obstruct sinus drainage, increasing the risk of sinus infections and polyps.
Surgical Relevance:
The nasal septum is often used in reconstructive surgeries as a graft material due to its cartilage structure.
