Structure of Nose

Nose is the primary organ of smell and functions as an important respiratory organ in the body. Besides this, it is also involved in functions such as tasting.

The air that we breathe is filtered through the nasal hair. The inhaled air is warmed and humidified before it enters into the lungs.

The shape of the nose is due to the bones and cartilages. The nasal septum separates the nostrils and divides the nasal cavity into two.

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The structure and function of the nose are mentioned in detail. Read on to explore the anatomy of the nose.

Nose Structure

The structure of nose is explained as follows:

1. Bone: It supports the bridge of the nose.
2. Cartilage: The upper cartilage provides support to the sides of the nose. The lower cartilage adds width and height to the nose. It provides shape to the nostrils and nose tip.
3. Nasal Cavity: It is the hollow space through which the air flows.
4. Septum: The septum divides the inside of the nose into two chambers. It is a thin wall made of bones and cartilage.
5. Mucus Membrane: The mucus membrane lines the nose, sinuses and throat. It moistens and warms the air we breathe in. It also forms a sticky mucus that prevents dust and other small particles into the nose.
6. Turbinates: Each side of the nose contains curved turbinates, and the bony ridges are lined with mucus membrane.
7. Sinuses: The bone around the nose contains hollow, air-filled chambers known as sinuses. The mucus flows into the nasal cavity from the sinuses.

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Functions of Nose

Following are the important functions of nose:

Helps in Inhalation

The process of respiration starts in the nose. The oxygen enters into the nose through the nostrils and exits the same way during exhalation. The nasal cavities open into a space called choana, which further opens into the nasopharynx. The air then enters the oropharynx and finally reaches the lungs via larynx, trachea and bronchi.

Purification of Inhaled Air

The walls of the nasal cavity are covered with hair or cilia that trap the dust and harmful particles and purify the inhaled air. The back and forth movement of cilia help in moving the dust particles to the throat where they are swallowed, or are excreted through the nasal cavity.

The nose hair also moisturizes and warms the air, so that it resembles the air temperature and moisture within the lungs. During exhalation, the heat and moisture present in the carbon dioxide is absorbed by the nasal hair and then released in the atmosphere.

The nasal conchae, that is spiral in structure, keeps whirling the air for a longer time within the nasal cavity so that it is humidified and purified properly.

Organ of Smell

The inhaled air comes in contact with the olfactory epithelium and the nerve fibres extending from the olfactory receptors accumulate the molecules containing the odour to send the signals to the olfactory bulbs through the receptors. These signals are carried to the olfactory region of the brain and are decoded so that the smell is identified.

Sense of Taste

While chewing, the food releases certain chemicals that travel up to the nose and activate the olfactory receptors inside the nose. They work in coordination with the taste buds to identify the actual flavour of the food.

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