Nose

NOSE

The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the septal cartilage (which separates the nostrils) and the upper and lower lateral cartilages. On average the nose of a male is larger than that of a female.

The nose has an area of specialised cells which are responsible for smelling(part of the olfactory system). Another function of the nose is the conditioning of inhaled air, warming it and making it more humid. Hairs inside the nose prevent large particles from entering the lungs. Sneezing is usually caused by foreign particles irritating the nasal mucosa, but can more rarely be caused by sudden exposure to bright light (called the photic sneeze reflex) or touching the external auditory canal. Sneezing can transmit infections, because it creates aerosols in which the droplets can harbour microbes.

  The nose is the body's primary organ of smell and also functions as part of the body's respiratory system.Air comes into the body through the nose. As it passes over the specialized cells of the olfactory system, the brain recognizes and identifies smells. Hairs in the nose clean the air of foreign particles. As air moves through the nasal passages, it is warmed and humidified before it goes into the lungs.

The most common medical condition related to the nose is nasal congestion. This can be caused by colds or flu, allergies, or environmental factors, resulting in inflammation of the nasal passages. The body's response to congestion is to convulsively expel air through the nose by a sneeze.

Nosebleeds, known medically as epistaxis, are a second common medical issue of the nose

The entire nasal cavity is lined with a mucosal surface made up of epithelial cells and glands that produce mucus. This mucus keeps the inside of the nose moist, traps allergens and other particles and helps keep the air you breathe in humid. Millions of cilia continually move the mucus layer across the mucosal surface, pushing harmful particles out of the nose in the process. In this sense, the nose is an air filter that purifies air before it reaches the lungs.