The nose is the median organ located in the center of the face, which constitutes the first entrance to the respiratory tract , and the organ of smell. The nose is made up of bones and cartilage , which support its structure and make it protrude from the plane of the face. Inside the nose are two long channels wrapped in a mucous membrane – the front parts of the nasal passages. The nasal passages open to the outside in the nostrils.
What is the nose?
The nose is made up of a bony part and a cartilaginous part . The bony part includes the nasal passages and the jaw. The cartilaginous part forms the tip of the nose . It is possible to distinguish the bones and cartilages that make up the nose by touching the back. By sliding your fingers from the tip of the nose towards the base, you can notice a difference in the texture of the fabric located under the skin, which gradually becomes harder.
There are two nasal pits : their anterior part opens towards the outside of the body through the nostrils , while the posterior part connects to the nasopharynx (which represents the upper portion of the pharynx) through two openings, called “coane” . The nasal pits are lined inside by the pituitary mucosa divided into two portions: an upper (called olfactory) and a lower (called respiratory). The respiratory mucosa is characterized by the existence of a vascular reticulatewhich allows the heating of the air that is inspired, as well as the presence of mucus and eyelashes which allow the humidification and filtration of the air itself. The portion of the olfactory mucosa is instead the seat of the olfactory cells, the olfactory bulbs and the olfactory nerves.
Outside, the two nasal pits have bone reliefs , which are lined with mucous membrane, and known as inferior, middle and superior turbinates. The two nasal pits are separated by the nasal septum , which is made up of cartilage and bone. The ethmoid bone forms the roof of the two nasal pits.
What is the nose for?
The nose has a respiratory and olfactory function . The nose forms a part of the upper respiratory tract . Air enters the nasal passages through the nostrils, thanks to the inspiration . Then the mucus and eyelashes present in the nasal passages warm, moisten and purify it, allowing it to continue on its path to the lungs . The olfactory signals are received by the upper wall that surrounds the two nasal pits , and transmitted to the brain by the bulb and the olfactory nerve , thus making the olfactory function possible.