Your incredible sense of smell can tell you so much about the world around you. It can give you pleasure (think, the wafting aroma of freshly baked challah), warn of danger (think, the smell of smoke or gas), and help you taste food. Life without scents, odors, and aromas would be pretty boring.
Smells are made from tiny chemicals that are inside of odor molecules. These molecules are really small – at most, a few nanometers in size (a nanometer is one-billionth of a meter) – and they float in the air.
Smelling starts with your nostrils. When you breathe in through your nostrils, the air, along with the odor molecules, travel into your nasal cavity, which is behind your nose and above the hard roof of your mouth. Inside your nasal cavity, you have a smelling factory called the olfactory epithelium (ol-FAK-tor-ee eh-puh-THEE-lee-um). It contains very tiny cell receptors that pick up and recognize odors. Your nose has between six million and ten million of these receptors! (Although this sounds like a lot, dogs have up to 300 million olfactory receptors! No wonder dogs have such a great sense of smell!)
These special receptor cells detect smells in the air that you breathe in, and send information about them to the parts of your brain that deal with emotion and memory. This is why smells from our past, such as a delicious bowl of cholent on Shabbos morning or the salty spray at the seashore, can bring back strong feelings and powerful memories.
Mother Nose Best
Women have a stronger sense of smell than men!
Words of Wisdom
When referring to Mashiach, Yeshayah Hanavi says, “V’haricho b’yirat Hashem… – And he will delight in the fear of Hashem…” (Yeshayah 11:3). “V’haricho – “and he will delight” has the same root as the word for “rei’ach – smell.” Chazal interpret this to mean that Mashiach will be able to judge through the sense of smell. Indeed, the Gemara (Sanhedrin 93b) discusses how a false Mashiach was detected because of his inability to judge by scent.
As with taste, our sense of smell is based on receptor cells (in the nose) detecting odor molecules floating in the air, and sending messages about them to the brain. Unlike taste, smell is a long-distance sense; we can sniff out certain odors from hundreds of yards away.
Makes Sense
Smell is the only one of the five senses directly connected to the area of the brain where memories are formed and emotions are processed.
Why Can’t I Taste When I Have a Cold?
When you have a cold, your nasal passages become swollen and produce extra mucus, which blocks your nose. This makes it difficult for your sense of smell to work. But why does a cold diminish your sense of taste?
The answer is that, although taste and smell are separate senses, with their own receptors, they are closely intertwined. While the tongue has thousands of taste buds to detect the five primary tastes (salty, sour, sweet, bitter, and umami), it’s the sense of smell that provides the rest of a food’s flavor. That is why it’s difficult to appreciate a food’s flavor when you have a nasal obstruction due to a cold or stuffy nose. However, you can still feel the texture and temperature of the food, since this information is processed on the tongue. That is why you are still able to distinguish whether the food you are eating is hot or cold, and coarse or smooth.
The Common Cold
In the United States, colds account for more visits to the doctor than any other condition!
Fact or Fiction??
Cold temperatures can cause a cold.
This is not true. Cold weather makes you cold, but it doesn’t cause a cold. Both the common cold and the flu are viruses, and they’re not hanging out in the wintry air but in other humans and the surfaces they touch. While the weather is not directly responsible for making people sick, the viruses that cause colds may spread more easily in lower temperatures, and exposure to cold and dry air is not good for the body’s immune system.
Selective Smelling
The same way that the brain can block out sounds that are unwanted, a similar block-out mechanism exists for odors. If you are overwhelmed by a particular odor, after a while you cannot detect it. This makes it possible for someone to tolerate an unpleasant odor after overcoming his initial dislike of it. However, the sensitivity of the smelling organs remains. Even in the stench of a garbage dump, a rose will still smell as sweet as ever.
The sense of smell is backed up by an excellent memory. Every odor that is recorded by the brain is stored away in a person’s long-term memory bank, where it remains ready for instant recall. There are distinctive smells of childhood, homes, gardens, cars, clothes, foods, flowers, etc. Each and every one of the thousands of different odors that enter our noses is faithfully filed away in a manner that no one can explain.
The ability to detect odor is a great kindness, one that we sometimes only appreciate when we temporarily lose our sense of smell due to a cold. The fact that there is such a variety of odors and aromas in flowers, fruits, and vegetables, each more pleasant than the next, and that so many millions of odor-sensing “machines” are consistently, faithfully, and humbly working hard at the top of our nose, is no accident. It points to a great plan and design, expertly created by the most brilliant Designer.