Your nose is the first stop in the respiratory system and is the main organ of the olfactory system. Despite sitting between your eyes, you don’t see your own nose because your brain ignores it - it filters it out from your view as it is not information you need to understand the world around you.
The shape of the nose is defined by cartilage and bone. The top of the nose is formed by the nasal, maxillae and frontal bones. The openings to the nose, called the nostrils or nares, are separated by the septum, a long piece of cartilage.
From the nostrils the air travels into the vestibules that contain hair follicles to clean out dust particles from it. It will then enter the nasal passages, a separate one for the left nostril and another for the right, which both open into two individual nasal cavities. At the top of each the nasal cavity is a small area located inside the skull called the olfactory region.
There are 12 bones that make up the structure of the nasal cavity, the nasal, maxilla, palatine and lacrimal bones, and the unpaired ethmoid, sphenoid, frontal and vomer bones.
This nasal cavity is further divided by bony horizontal shelves (called the inferior, middle and superior nasal conchae) to create four air channels in each cavity and also help to filter the air. Going from the bottom to top, these are the inferior nasal meatus, middle nasal meatus, superior nasal meatus and sphenoethmoidal recess.
If that wasn’t complicated enough, there are four pairs of air-filled areas recessed inside the skull that surround the nasal cavity, called paranasal sinuses. They warm and moisten the air before it reaches the lungs.
Named after the bones in which they’re found, the sinus above the eyes in the centre is called the frontal, under the eyes is called the maxillary, the ethmoidal is between the eyes and the sphenoidal is behind the eyes.
Sense of smell
Not only does the nose bring in air for breathing, but it also controls one of the five senses, smell or olfaction. Smell is the only one of the five senses that is fast tracked directly to where memories and emotions are processed in the brain.
Smell is processed in the upper nasal cavity, the olfactory region, which is lined with receptors and olfactory cells (there are around 12 million of them!). These cells and receptors interact with odorant molecules that are breathed in, which then pass on the chemical signals to the olfactory bulb. The is technically a part of the frontal lobe of the brain rather than the nose, however it is on a long stalk so is positioned directly above the nasal cavity.
Nose related AnatomyStuff resources:
Ear, Nose and Throat Chart / Poster - Laminated
Nose Model with Paranasal Sinuses (5 part)
Nose and Olfactory Organ Model Set (4 times life size)
Transparent Prenasal and Mastoid Sinus Model
Head Section Model with Sinusitis
Further reading / sources
View of the two nasal cavities
Why can’t I see my nose?