The turbinates, also known as nasal conchae, are complex structures inside the nose that play a fundamental part in the respiratory system. They condition the air before it reaches the lungs, transforming cold, dry, and dirty air into air that is warm, moist, and clean. Turbinates are specialized projections that manage the flow and quality of air, protecting the delicate tissues of the lower respiratory tract from irritation and damage.
Precise Location and Structure
The turbinates are located deep within the nasal cavity, projecting from the side walls toward the nasal septum, which divides the nose into two passages. They are long, narrow, and curved structures, resembling miniature seashells, which is why they are also called conchae. This anatomical design significantly increases the surface area inside the nose, maximizing interaction between the inhaled air and the nasal lining.
Humans typically have three pairs of these structures: the superior (upper), middle, and inferior (lower) turbinates. The inferior turbinate is the largest of the three and is a separate bone, while the superior and middle turbinates are projections of the ethmoid bone. Each turbinate hangs over a corresponding groove-like air passage called a meatus, which helps direct the airflow.
The inferior meatus is found beneath the inferior turbinate, and the middle meatus lies between the inferior and middle turbinates. The superior meatus is located beneath the superior turbinate. These passages are significant because they serve as drainage sites for the paranasal sinuses and the tear ducts.
The Essential Role of Turbinates
The primary function of the turbinates is to prepare inhaled air for the lungs, acting as the body’s natural air conditioner. This process involves three specific actions: warming, humidifying, and filtering the air. The structures are covered in a specialized, highly vascular mucous membrane known as respiratory epithelium.
The rich blood supply allows the turbinates to warm the air quickly to body temperature. As cold air passes over the highly vascularized tissue, heat is transferred from the blood vessels into the airstream. Simultaneously, the mucous membrane secretes moisture, which humidifies the air, preventing dryness in the lower respiratory tract.
The mucous layer also acts as a sticky trap for dust, allergens, and microscopic particles. Ciliated cells within the membrane sweep this contaminated mucus toward the throat, where it is swallowed and neutralized. By performing these functions, the turbinates protect the lungs from irritation and infection.
When Turbinates Cause Trouble
While normally beneficial, the soft tissue covering the turbinates can sometimes swell and cause problems with nasal breathing. This enlargement, most commonly affecting the inferior turbinates, is known as turbinate hypertrophy. The swelling occurs because the tissue contains erectile-like tissue and a dense network of blood vessels that can expand rapidly in response to inflammation.
Common causes of this chronic inflammation include environmental irritants, seasonal or perennial allergies, and persistent sinus infections. When the turbinates become chronically enlarged, they can obstruct the nasal passages, leading to difficulty breathing through the nose. This obstruction often results in prolonged nasal congestion, mouth breathing, snoring, and a dry mouth upon waking.
The excessive swelling narrows the space available for airflow, forcing a person to breathe through their mouth, which bypasses the nose’s natural conditioning system. If left unaddressed, chronic turbinate enlargement can worsen symptoms and may contribute to frequent sinus infections. A deviated nasal septum can also contribute to the problem, as it can cause the turbinate on the opposite side to swell in compensation.