Nose is the projected part of the face and the most important air pathway to the lower respiratory system and the most prominent aesthetic feature of the face. Conditioning, warming and humidifying of the inhaled air are considered as functional roles of the nose.
By breathing through the nose, you prevent large particles entering the lungs. Moreover, there are special nerve cells called olfactory neurons inside the nose that lie on the roof of the nasal cavities. These olfactory neurons are located in the olfactory epithelium and are connected to brain via nerves.
External anatomy of the nose
Shape of the nose is almost like a pyramid.
Upper part of the nose is narrower and lower part of the nose is wider. The upper third of the nose is bony and the lower two thirds are cartilaginous.
dorsum (nasal ridge)
The distance between tip and root of the nose is called “dorsum”. Dorsal hump occurs when dorsum’s bone and cartilage grow excessively.
In Latin, columella means small column. As the name implies, columella acts as a small column which is situated between the nostrils.
Ala (wing of the nose)
Walls of the nostrils are called alae (= plural of ala). Alae are responsible for keeping the nasal cavities open. During the rhinoplasty, strength of the alae needs to be maintained; otherwise the patient may suffer breathing problems after nose surgery.
Largeness of the nasal bone or largeness of the cartilaginous part of the nasal septum and often both of these factors are the reason(s) why dorsal hump occurs. To remove the dorsal hump, bone and cartilage of the dorsum is removed to straighten the ridge of the nose. Care needs to be taken while performing this bone/cartilage reduction during the rhinoplasty; because too little reduction will not solve the problem and too much reduction might result in bad nose deformities like slide-shaped nose or saddle-shaped nose.
Internal anatomy of the nose
Internal part of the nose is lined with a mucous membrane called nasal mucosa.
There are two types of mucosa inside the nose:
• Respiratory mucosa: main lining of the nasal cavity which covers the majority of the internal surface of the nose
• Olfactory mucosa: Covers only a small part of the nasal cavity roof.
Normally, each person has 3 bony protrusions on each side of the nose which is called turbinate or concha. The air we breathe passes through these bumps where different respiratory functions such as conditioning, humidifying and warming of the inhaled air are performed.
Lateral walls are located on each side of the nose. The lower half of these walls is made up of cartilage and the upper part is made up of bone. During the rhinoplasty, if we want to narrow the nose, we relocated these walls toward inside. Too much relocation of the side walls makes respiratory pathways abnormally narrow.
The thin, bony-cartilaginous partition which shapes and separates the two nasal cavity is called the nasal septum. Septum is a protecting structure of nose which supports other components of the nose.
Paranasal sinuses are four pairs of hallow cavities which are located around the nose . they are inside the facial bones and open by some meatuses to the nose. For better imagination, sinuses connect to nose in the way that a few rooms connect to a main corridor. In the above example , the main corridor is the nose and the rooms are the sinuses. The main function of paranasal sinuses has not been discovered yet. Apparently though, conditioning of the inhaled air and boosting the resonance of the voice are their possible functions.
The terminal parts of the nasal cavities join at the pharynx and deliver the inhaled air to the throat.