2.The shape of nose depends on the ethnic background of a person.
Positions of lower and upper lateral cartilages and nasal bones actually define nose shape.
3. Different people have different sneezing styles and these styles are genetically determined. So, the members of a given family will have similar sneezing styles which will be different than the sneezing styles of other families.
4.. During sneezing, irritants (that cause sneezing) are expelled at a speed of 100 miles per hour.
5. In women, nose grows until the age of 15 to 17 and for men, it is 17 to 19.
6. Nose droops and lengthens over time because of gravitational pull. This happens because elastin and collagen in nasal tip breaks.
7. The best air filter in this world is human nose. Human nostrils are lined up with hair responsible for blocking germs and dust. Grooves in nasal cavity make air swirl like stream currents. This is when the inhaled hair is moistened and warmed so that the sensitive tissues of the lungs can be protected. It is during this filtration process that the mucus lining of the nasal cavity captures cold viruses and pollen which cannot be stopped by hair in nostrils.
8. Mucus is produced by human sinuses and nose and it contains white blood cells and enzymes responsible for fighting infections. One quart mucus is produced daily.
9. When someone inhales dry air, the air picks up moisture content from mucus. This makes the mucus pasty, which is known as snot or boogers.
10. When a person becomes sick because of flu, the nose becomes runny. This happens because the nose produces more mucus than usual in an attempt to kill microbes invading the body. Humans are capable of detecting 10,000+ scents. Humans can detect smell with special types of cells known as olfactory nerve cells. There are nearly 12 million olfactory cells present in a normal human. However, this number gradually decreases with age.
11. Olfactory nerves from nose have direct connection with brain. It is because of this that several types of smells can bring memories back.
12. Sense of smell is the only one of the 5 senses in humans which has direct connection with hippocampus – the part of the brain responsible for formation of memory.
Humans release pheromones – a type of chemical released only in response to sexual attraction. Nasal grooves in nostrils are sites rich in pheromones. Human nose is capable of detecting pheromones of opposite sex. According to experts, it is the pheromones in nose that led to the birth of smooching or romantic kissing.
13. Anything that human nose cannot smell is lethal to humans. For example, human nose cannot smell natural gas (one that humans can smell is actually a different compound called mercaptan added to natural gas), carbon monoxide, carbon dioxide etc.
14. Humans don't smell with nose. It is the brain that does the job. The olfactory nerve cells in nose are only responsible for capturing smell and sending them to the brain. It is the brain where the smell gets identified.