Sinonasal tract

The sinonasal tract is an area inside your head that includes the nasal cavity (the open space inside your nose) and the paranasal sinuses. The paranasal sinuses are small, air-filled spaces located around your nasal cavity, including:

• Maxillary sinuses (under your eyes, behind your cheeks)

• Frontal sinuses (above your eyes, behind your forehead)

• Ethmoid sinuses (between your eyes)

• Sphenoid sinuses (deep behind your nasal cavity)

What does the sinonasal tract do?

The sinonasal tract helps warm, moisturize, and filter your air. It also plays a role in your sense of smell and produces mucus (a slippery substance) that traps dirt, bacteria, and other particles from the air, keeping your lungs healthy.

How is the sinonasal tract structured?

A thin layer of specialized cells called the epithelium lines the inside surface of your nasal cavity and sinuses. These epithelial cells form a protective barrier, helping keep harmful particles out of your body.

Beneath the epithelium is a layer of supportive tissue called the stroma. This layer contains blood vessels and tiny round structures known as glands. These glands produce mucus (also called mucin), which helps keep the nasal passages moist and clean.

Together, the epithelial cells and underlying stroma make up the sinonasal mucosa.

Why is the sinonasal mucosa important?

The sinonasal mucosa protects your respiratory system from infections and irritation. Producing mucus helps remove harmful particles and bacteria, preventing them from reaching your lungs. A healthy sinonasal mucosa contributes to easier breathing and a strong immune defense.

What kinds of problems can occur in the sinonasal tract?

Several medical conditions can affect the sinonasal tract, including:

• Sinusitis: Inflammation or infection of the sinuses, causing congestion, pain, and pressure.

• Allergies: Swelling and irritation due to reactions to pollen, dust, or other allergens.

• Sinonasal polyps: Non-cancerous growths in the nasal cavity or sinuses that can block airflow.

• Sinonasal cancers: Rare tumors arising in the sinonasal mucosa.

Doctors and pathologists can examine samples from the sinonasal tract to diagnose these conditions and recommend appropriate treatments.

Questions to ask your doctor

If you have concerns about your sinonasal tract, consider asking your doctor:

• What symptoms should I watch for if I have sinus or nasal problems?

• How can I keep my sinonasal tract healthy?

• Do I need tests or treatments for frequent sinus or nasal symptoms?

• What treatments are available if I have chronic sinus issues?

Understanding the sinonasal tract can help you stay informed about your respiratory health and be actively involved in your medical care.