Anatomy of the nose and paranasal sinuses

We use our sense of smell for many things, like smelling cookies baking in the oven, but we also use it to help us taste, like when we take a big bite of those cookies!

Our sense of smell is thanks to our nose, but actually our nose does much more than just smell. It also provides a passage for air to reach the lungs, and also helps warm and filter that air before it gets down there. Now, let’s see what the nose knows!

Now, the external nose is the part that we see protruding from the midline of our face. Generally speaking, the nose has a pyramidal-shaped structure with two openings called the nares or nostrils. These openings are surrounded laterally by the alae - meaning wings - of the nose, and separated from one another medially by the nasal septum.

Inside the nostrils is the nasal vestibule, which is lined by skin and small hairs that help filter dust particles from the air that passes through. The dorsum of the nose begins at the root, located between the eyebrows, and slopes downwards to the apex, which is the tip of the nose.

Okay, so our external nose has a skeleton that helps support its structure, made up of hyaline cartilage and bone. The hyaline cartilage is on the more anterior portion of the nose, and provides most of its structure.

In the midline, there is the cartilaginous part of the nasal septum, or septal cartilage. Two lateral cartilages extend from either side of the dorsal aspect of the septal cartilage. Anteroinferior to these lateral cartilages are the paired alar cartilages that form the apex and part of the nares of the external nose. The alar cartilages are thin and flexible, allowing for dilation or constriction of the nares.

The bony skeleton gives a base to the nose and includes the nasal part of the frontal bone - located at the root of the external nose - two paired nasal bones, the frontal processes of the maxillary bones, and in the midline, there is a superior and posteroinferior bony part of the nasal septum.

The superior part is formed by the perpendicular plate of the ethmoid bone, while the posteroinferior part is formed by a small flat bone known as the vomer with some contribution from the maxillary and palatine bones.

Let’s take a peek inside the nose now! As we enter the nasal cavity, we first pass through the nares into the nasal vestibule, which is lined by skin. Moving deeper, past the vestibule, the nasal cavity is no longer lined with skin, but with nasal mucosa.