Anatomy of the Nose: Human Nose Structure

Nose is the most prominent feature located in the middle of the face of humans. It is the beginning part of the respiratory system that is involved in inhalation. The important functions of nose are to filter the atmospheric air before passing it further into the respiratory system and to provide the sense of smell. In fact, it acts as an interface between the air of the body’s respiratory passages and the air of the atmosphere. The atmospheric air entering through the nostrils is led to the nasal cavity, which further passes to the pharynx, trachea, bronchi and finally, to the lungs.

Anatomy of the Nose: Human Nose Structure

The structure of a human nose is composed of bones, cartilage and fibro fatty tissues. The external feature of a nose or the type of nose depends upon the ethmoid bone and the cartilage. According to the shapes and sizes of human nose, they can be classified into different types such as the Roman or aquiline, the Greek or straight, the Nubian, the hawk, the snub and the turn up types. Human races can be identified by the type of nose, for example, the Europeans have long, narrow, large elevation (height of the nose tip above the lip) and vertically set nostrils. Supporting structure of the upper part of nose is mostly made up of bones. The topmost portion near the eye sockets consists of two nasal bones, which is linked to the frontal bone of the forehead. These nasal bones are joined to form the nose bridge. On the sides, they are connected with the lateral process of the maxilla by a tough fibrous membrane. At the base, nasal bones are connected with septal and lateral nasal cartilage.

The lower part of the nose is made up of cartilages. These cartilages give shape to the external feature of the nose. The nose bridge continues with the septal cartilage to form the nasal septum, which separates the nostrils. The nostrils continue with the nasal cavity. There are three horizontal outgrowths of bones, called turbinate or conchae, which divide the nasal cavity into three groove-like air passages. Conchae increase the surface area of the nasal cavity. The three turbinates are named as inferior, middle and superior turbinates, according to their position and functions. They are important for maintaining the temperature, humidification (upto98% water saturation) and filtration of the air when it passes.

On either side of the septal cartilage, there lies the lateral nasal cartilage. Just below the lateral nasal cartilages, the greater alar cartilage is present, which is a thin, flexible plate that forms the medial and lateral wall of the nostril. In addition to greater alar cartilages, there are three or four small cartilages that are called as lesser alar cartilages. Both the greater and lesser alar cartilages give the overall shape of the nostrils.

Hair are present inside the nostrils that help in filtration and humidification as the air from the atmosphere passes them. Hence, nose hair serve as a defense mechanism against the harmful pathogens and solid particulate matter present in the air. Both the nostrils and nasal cavity are lined by mucous membranes along with cilia. The mucous membrane secretes a sticky substance called mucus. The mucus and cilia filter the air and prevent the entry of foreign particles such as microorganisms, dust and particulate matter inside the respiratory system. The mucus also helps in moistening the air. Underneath the mucous membrane, there are blood capillaries that help to warm the air.

The bones of the face around the nose region contain sinuses. Sinuses are hollow air cavities that are lined by mucous membrane (similar to the nasal cavity) and are also known as paranasal sinuses. Symptoms in any of the paranasal sinuses cause certain sinus problems. There are four subgroups of sinus, classified depending upon the bones to which the sinuses are present. They are frontal, maxillary, ethmoid and sphenoid sinus. Among these four sinuses, ethmoid sinus is located around the area of nose bridge.

Overall, nose is responsible for respiration and for providing the sense of smell. At present, nose surgery or rhinoplasty is performed to improve the appearance of the nose and also to correct different medical problems such as deviated septum, which impairs the respiration process. A deviated septum may be present at birth or may be resulted due to an accident. Today, nose surgery has become an important part of cosmetic or plastic surgery.