The composition of the nasal septum is a frequent source of confusion. This internal wall is often thought to be entirely bone or entirely cartilage, leading to questions about its flexibility and strength. The truth is that this central structure that divides the nasal passages is a sophisticated blend of both tissue types. Understanding the specific components of the septum is key to grasping how it supports nasal function and why it is susceptible to certain common issues.
Defining the Nasal Septum
The nasal septum is a vertical sheet located centrally within the nasal cavity, acting as the partition that separates the left and right air passages. It extends from the nostrils backward to the nasopharynx, which is the upper part of the throat behind the nose. This dividing wall is positioned along the midline and is covered on both sides by a specialized mucous membrane.
The septum’s physical boundaries are formed by the floor of the nasal cavity below and the roof of the nasal cavity above. This anatomical positioning ensures that inhaled air is channeled efficiently into two distinct streams. The mucosal lining covering the septum is important for its physiological roles, adding a soft tissue layer to the underlying framework of bone and cartilage.
The Dual Nature: Cartilage and Bone Components
The septum’s structure is a combination of cartilage in the front and bone toward the back, giving it both resilience and stability. The anterior and lower portion consists primarily of hyaline cartilage, specifically known as the septal cartilage. This flexible tissue allows the tip of the nose to move and provides a degree of shock absorption against minor impacts.
The posterior and upper parts of the structure are composed of thin, flat bones fused together. Two major bones form the majority of this bony framework: the perpendicular plate of the ethmoid bone, which makes up the upper section, and the vomer bone, which forms the lower and back section. This bony foundation connects to the skull base and the palate, establishing a rigid anchor for the entire nasal structure.
Functions of the Septum
The primary function of the septum is to provide necessary structural support to the entire external nose, maintaining its shape and projection. It acts as a foundational support beam, connecting the upper bony segments of the face to the lower, more mobile cartilage. A straight septum ensures that the nasal cavity is divided equally, which is necessary for the proper regulation of airflow.
The septum is important for directing the air stream smoothly and evenly through both nasal passages. This equal distribution of air allows the mucosal lining to function optimally by warming, humidifying, and filtering the inhaled air before it reaches the lungs. The efficient passage of air is directly connected to the septum’s ability to remain aligned and structurally intact.
Common Structural Issues
The most common structural problem involving this partition is a deviated septum, where the wall is significantly off-center. Approximately 80% of people have some degree of misalignment, but only a pronounced deviation causes noticeable problems. This displacement often occurs during fetal development, is sustained during the birth process, or results from an injury to the nose later in life.
A severe deviation can cause the septum to push into one side of the nasal cavity, obstructing airflow and making breathing difficult. Symptoms can also include frequent nosebleeds because the narrowed passage causes the mucosal surface to dry out more easily. When the symptoms are severe enough to interfere with daily life or sleep, a surgical procedure called a septoplasty may be performed to straighten and reposition the cartilage and bone.