How Does the Nose Work?
- The nose is composed of two large passages through which you inhale and exhale air. The septum, which is composed of thin bone and cartilage, divides the passages before they lead into four sinus cavities. These sinus cavities are located above, behind, and below your eyes. Your nose helps you to breathe, smell, and taste.
- Air is filled with molecules, whose emissions make their way into your nose where they connect with, and attach to, cilia. Cilia are the little hairs that line your nasal passages. Their function is to trap unwanted particles, such as dust and dirt, and to assist with your sense of smell.
- If you slice an apple in half and breathe in its scent, the apple's molecules enter your nose and attach to the cilia. When this happens, the olfactory receptor neurons attached to the cilia are activated, allowing you to distinguish that the object is an apple.
- There are over 10,000 odors that humans are able to identify through the olfactory receptor neurons. Each olfactory receptor neuron is encoded with a different gene. If you are missing or have a damaged gene, you will not be able to distinguish the smell related to that particular gene.
- When you chew food, chemicals are released into your nose and deciphered by the olfactory receptor neurons. During illnesses, such as a cold or sinusitis, your nasal passages become congested. A stuffy nose keeps you from tasting food because the olfactory receptor neurons are blocked. If you cannot smell, you will not be able to taste, because these senses are related to each other.
- The air that you breathe in is conditioned by the nose and sinuses, or nasal cavities. Moisture is produced within these cavities, and air is therefore humidified before it passes down the trachea and into your lungs. The sinuses are also responsible for cleaning the air that you breathe. The mucous within these cavities traps particles that make it past the cilia, acting as a natural air filter. Air's passage through the nasal cavities, sinuses, and trachea warms it before if reaches your lungs. The clean, warm, and humid air is now ready to be absorbed and move into the circulatory system, which distributes oxygen to all areas of your body.
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