The nasal passages are central to the respiratory system, serving as the initial pathway for the air we breathe. They perform several important functions, preparing inhaled air before it reaches the lungs. This preparation helps to protect the delicate tissues of the lower respiratory tract.
Understanding Their Location and Structure
Within each side of the nasal cavity are structures known as nasal conchae, also referred to as turbinates. These are long, thin, curved bones that project from the lateral walls of the nasal cavity. Humans have three pairs: superior, middle, and inferior nasal conchae. The inferior concha is the largest and most active in airflow.
These bony projections curl medially and downward into the nasal airway, creating a scroll-like arrangement. Each concha is covered by a mucous membrane, which is thick and rich in blood vessels. This increases the internal surface area of the nasal cavities. The superior and middle conchae are parts of the ethmoid bone, while the inferior concha is a separate bone entirely.
How They Function in Respiration
The nasal conchae condition the air we inhale. Their primary functions include warming, humidifying, and filtering air before it reaches the lungs. Their curved shape creates a large surface area, allowing contact between incoming air and mucous membranes.
The rich blood supply within the mucous membranes warms inhaled air to body temperature. The mucous membranes produce mucus, which adds moisture to the air, ensuring it is humidified. This mucus also acts as a trap for dust, pollen, and other airborne particles, preventing them from entering the lungs. The turbulent airflow generated by the conchae further promotes the deposition of these particles onto the mucous layer, where they can be cleared.
Common Conditions Affecting Them
The nasal conchae can become enlarged, a condition known as turbinate hypertrophy, which hinders proper breathing. This enlargement often affects the inferior turbinates. Common causes include allergies, recurrent infections (like the common cold or sinusitis), and environmental irritants. Hormonal changes or a deviated nasal septum can also contribute to this condition.
Symptoms of enlarged conchae include persistent nasal congestion, difficulty breathing through the nose, snoring, and an altered sense of smell. An air-filled pocket, or cyst, can develop within a turbinate, typically the middle one, leading to a condition called concha bullosa, causing obstruction.
Treatment varies depending on the cause and severity. Initial management often involves medications such as nasal steroid sprays, antihistamines, or decongestants. If non-surgical methods do not provide sufficient relief, surgical procedures like turbinate reduction may be considered to reduce conchae size and improve airflow. These procedures can involve techniques such as cauterization or trimming excess tissue.