Your cart is currently empty!
M01.02.016 Nasal Skeleton
The nasal skeleton forms the structural framework of the nose, comprising both bone and cartilage. It contributes to the external appearance of the nose and the internal nasal septum, which divides the nasal cavity into two separate passages.
This guide provides a detailed overview of the nasal skeleton, focusing on its anatomical structures, components, and clinical significance.
Components of the Nasal Skeleton
The nasal skeleton is composed of three tissue types:
- Bone
- Cartilage
- Fibro-fatty tissue
The skeleton is divided into two parts for study:
- External Nasal Skeleton
- Internal Nasal Septum
1. External Nasal Skeleton
The external nasal skeleton extends the nasal cavities to the front of the face. It is composed of the following:
Bone Structures
- Nasal Bones: Located superiorly.
- Maxillary Bones: Support the nasal framework.
Cartilage Structures
The inferior portion is made up of hyaline cartilage, which includes:
- Lateral Cartilages: Contribute significantly to the nose’s shape.
- Major Alar Cartilages: Form the nostrils.
- Minor Alar Cartilages: Usually 3–4 on each side, variable in number.
- Cartilaginous Septum: Extends the nasal septum anteriorly.
| Component | Description |
|---|---|
| Nasal bones | Superior, provides rigid support. |
| Maxillary bones | Base of the nasal skeleton. |
| Lateral cartilage | Largest cartilage in the external nose. |
| Major alar cartilage | Shapes and defines the nostrils. |
| Minor alar cartilage | Variable, adds to nasal flexibility. |
2. Internal Nasal Septum
The internal nasal septum divides the nasal cavity into two nostrils and is formed by a combination of paired and unpaired bones, as well as cartilage.
Bones of the Nasal Septum
- Paired Bones:
- Nasal bones.
- Maxillary bones.
- Palatine bones.
- Unpaired Bones:
- Ethmoid Bone: Forms the central portion.
- Vomer Bone: Forms the posterior portion.
Cartilage
- Septal Cartilage: Anterior component.
- Greater Alar Cartilage: Adds to nasal septum structure.
Additional Structures
- Floor of the Nasal Cavity: Formed by the hard palate (palatine bone posteriorly, maxilla anteriorly).
- Roof of the Nasal Cavity: Formed by the cribriform plate of the ethmoid bone.
| Component | Role in Nasal Septum |
|---|---|
| Ethmoid bone | Central structural component. |
| Vomer bone | Forms the posterior nasal septum. |
| Septal cartilage | Supports the anterior nasal septum. |
| Palatine bone | Posterior floor of the nasal cavity. |
| Maxillary process | Anterior floor of the nasal cavity. |
Clinical Relevance
Nasal Fractures
- Commonality: Most frequent type of facial fracture.
- Cause: Typically results from blunt trauma.
- Complications:
- Permanent deformity due to bone and cartilage disruption.
- Difficulty in breathing if the septum is displaced.
Points to Remember
- The external nasal skeleton consists of both bones (nasal and maxillary) and cartilage (lateral, alar, and cartilaginous septum).
- The internal nasal septum divides the nasal cavity and involves paired bones (nasal, maxillary, palatine) and unpaired bones (ethmoid, vomer).
- The hard palate forms the floor of the nasal cavity, while the cribriform plate forms the roof.
- Nasal fractures are common and can lead to permanent deformity if untreated.