The nose is built to smell, and to moisten and filter the air we breathe.
The human nose is more than just a flap of flesh and cartilage on the front of the face. Besides being part of the respiratory system that inhales oxygen and exhales carbon dioxide, the nose also contributes to other important functions, such as hearing and tasting.
Size and shape
Human noses can have a wide array of shapes and sizes due to genetics and injuries. Men generally have larger noses than women, researchers say. According to the Guinness Book of World Records, the largest human nose on a living person belongs to Mehmet Ozyurek of Turkey. His nose is 3.46 inches (8.8 centimeters) long from the bridge to the tip.
Function
The two openings in the nose care called nostrils, or napes. They lead to two nasal cavities that are separated by the septum, a wall of cartilage. Inside the face is an intricate system of canals and pockets of air called sinus cavities. Sinus cavities span all the way to the back of the skull, right above the oral cavity, within the cheekbones and between the eyes and brows. All of these areas are responsible, at least in part, for breathing, smelling, tasting and immune system defense.
The human nose can smell over 1 trillion scents, according to researchers. The nose smells with the olfactory cleft, which is the roof of the nasal cavity. It is right next to the “smelling” part of the brain, which consists of the olfactory bulb and fossa. This part of the nose has many nerve endings that carry smell sensations to the brain, according to the American Rhinologic Society.
The nasal passageways on either side of the nose open into the choana and then into a chamber called the nasopharynx, which is the upper part of the throat. This chamber opens into the oropharynx, the throat area behind the mouth. When air is inhaled through the nostrils, it travels through the nasal passages, the choana, the nasopharynx, the oropharynx and the voice box and ends up in the lungs. Basically, in the respiratory system, the nose is a passageway for air.