The nasal septum acts as a dividing wall within the nasal cavity, separating it into distinct left and right passages. Located centrally within the nose, it runs from front to back. Its primary function is to guide airflow and contribute to the overall integrity of the nasal architecture.
Bony and Cartilaginous Components
The nasal septum is composed of both bone and cartilage. The septal cartilage, also known as the quadrangular cartilage, forms the front portion. This hyaline cartilage has a quadrilateral shape, completing the anterior separation of the nasal cavities.
Behind this cartilaginous part, the septum transitions into bony components. The perpendicular plate of the ethmoid bone forms the upper and central part of the bony septum, descending from the base of the skull. Below it, the vomer bone forms the lower and posterior part. These two bones articulate, forming the main bony framework. Other bones, such as parts of the maxilla and palatine bones, also contribute to the septum’s base.
The Septum’s Essential Role
The nasal septum plays an important role in maintaining healthy respiratory function. It ensures air flows efficiently through both nasal passages, allowing the nose to condition inhaled air before it reaches the lungs.
The septum supports the nose’s structure, maintaining its shape and internal architecture. It also contributes to the humidification and warming of incoming air, adding moisture and raising its temperature to protect delicate lung tissues. The septum aids in filtering out particles from the air, acting as a first line of defense against airborne irritants.
When the Septum Isn’t Straight
Many people have a nasal septum that is not perfectly straight, a condition known as a deviated septum. This occurs when the dividing wall of bone and cartilage is off-center, making one nasal passage smaller than the other. While some deviation is common and often goes unnoticed, about 80% of people have some degree of deviation.
A deviated septum can be present from birth, sometimes due to developmental factors or injuries during childbirth. It can also develop later in life from trauma to the nose, such as from sports or accidents. When the deviation is significant, it can lead to various symptoms.
Common issues associated with a deviated septum include difficulty breathing through one or both nostrils, particularly during colds or allergies. Some individuals may experience frequent nosebleeds because the dry surface of a deviated septum can be more prone to irritation. Other symptoms include noisy breathing during sleep, such as snoring, and sometimes headaches or facial pain.