Nasal Cavity:

The nasal cavity is a large air-filled space, functioning as a breathing passage, in the middle of the face. The nasal cavity extends back from the tip of the nose into the head as far as the ears.

Nasal Septum:

The nasal septum is the vertical wall in the middle of the nose that separates the right and left nasal cavities. This wall extends back to the end of the nasal cavity and is made up of cartilage in the front and thin bone in the back. The main functions of the nasal septum are structural support for the nose and regulation of air flow in the nasal passages. The nasal cavities and nasal septum are lined with a thin and soft membrane of tissue called mucosa.

Turbinates:

A turbinate is a long, narrow, and curled bone which protrudes into the nasal cavity. Each turbinate is covered with mucosa. The side walls of the nose each have three turbinates called the superior, middle and inferior turbinate. The turbinates change in size (enlarge & shrink) alternatively on each side at regular intervals.

The space between each turbinate is called a meatus, and each meatus is named for the turbinate above it. The inferior turbinate, which is the largest turbinate, runs parallel to the floor of the nose. The nasolacrimal duct (tear duct) drains tears into the inferior meatus (this explains why one develops a runny nose when one cries). The middle turbinate is located above the inferior turbinate. The majority of the sinuses drain into the middle meatus via small openings called ostea. The superior turbinate, which is the smallest turbinate, is located above the middle turbinate.

Importance of Turbinates:

• Turbinates, along with the septum, help us feel or perceive the level of airflow through our nose.
• Turbinates clean and filter the air so that irritants such as dirt and dust do not enter the lungs.
• Turbinates humidify the air to help prevent dryness of the lungs.
• Turbinates warm the cold air to the body’s temperature to help the lungs function more effectively.

Definition of Nasal Sinuses:

Nasal sinuses are hollow, air-filled spaces, within the bones of the skull and face. We possess four pairs of sinuses, and each sinus connects to the nasal cavity through small openings called ostium. Each sinus is named for the bone within which it is located:

• Maxillary Sinus - There is one maxillary sinus on each side of the nose, located under the eyes, in the cheeks.
• Ethmoid Sinus - There is approximately 6-12 small ethmoid sinuses on each side of the nose, between the eyes.
• Frontal Sinus - There is one frontal sinus on each side of the nose, located above the eyes, in the forehead.
• Sphenoid Sinus - There is one sphenoid sinus on each side of the nose, located behind the ethmoid sinuses near the middle of the skull, behind the eyes.

Importance of Nasal Sinuses:

Nasal sinuses are covered with a special lining similar to the lining in the nasal cavity called mucosa. This lining secretes mucus, a complex substance that keeps the nose and sinuses moist. The mucus also helps trap dust, viruses, and bacteria and removes them from the nose. The sinus mucosa is ciliated; that is, each cell on its surface has a cilium, a hair-like structure that has the capacity to push sinus mucus. This movement of mucus (which is known as mucociliary clearance) is responsible for clearing the sinuses and nasal cavity of substances trapped in the mucus.