Nose If the nose of Cleopatra had been a little shorter the whole face of the world would have been changed. – Blaise Pascal (1623 -1662), French mathematician, physicist, and religious philosopher. Nose, at the center of the face, maintains a delicate balance of beauty agreeable to the eye. While the external features are only for the passage of air, its primary job is to breathe and smell. Human nose has the capacity to recognize up to 10,000 separate odors. Odor needs to be volatile which is capable of entering nose as a gaseous state. Inside the nose there are olfactory epithelium (mucous membranes) located on the roof and upper part of both walls of the nasal cavity. Epithelium has some 5 million olfactory neurons and their support …show more content…
Recent researches have unfolded the ways nose distinguishes one odor from another. Like eye distinguishes the colors with only three receptors that recognize the red, green and blue, the nose does it more comprehensive way. As the odor molecules drift through the nose, they combine with certain specific odor receptor – just like the key that fits into the keyhole. So, unlike vision which happens in the brain, distinguishing the smells of hundreds of varieties takes place inside the nose itself. The human eye can distinguish approximately 2 million distinct colors. But the human nose, researchers say, can distinguish more than a trillion different smells. Even nose knows which food is fattier. Human nose has been evolved to be able to detect tiny differences among smells -- say the difference between fresh food and stale food or something just beginning to spoil. Researchers conducted a study relating to people’s ability to smell food-based and non-food-based smells both before and after meal. The findings are interesting but counter-intuitive: participants get heightened sensitivity to the non-food smell when they are hungry, and are able to smell the food better only after the meal. In other study researchers find that when women overeat and gain weight, they get less pleasure from eating. Their brain scans reveal that after eating there is less activity in the ‘reward’ pathways of the brain – the neurological corridors that respond to pleasure. Obese people have fewer pleasure receptors in the brain suggesting that overeating blunts the reward