The sense of smell is the only sense directly connected to the human brain, and the nose can distinguish about 1,000 billion different scents.
Humans can perceive several million colors and nearly half a million distinct tones. The sense of smell is unique among the five senses, from how many different scents the nose can detect to the connection between smell and overall health.
The only sense that connects directly to the brain
Scent cells are replaced every 30-60 days. The sense of smell is the only sense that is directly connected to the brain, controlled by nerves that originate in the brain. These nerves also control body functions including eye movement, hearing, taste, and vision.
The sense of smell is undervalued compared to the other senses.
The human sense of smell is better than many people think. The sense of smell is underestimated because it only works for the purpose of smelling, while other senses such as the eyes and ears, in addition to their main function of hearing and seeing, also perform many other roles.
The nose can smell 1,000 billion different scents.
In 2014, Rockefeller University in the US tested the human sense of smell using different mixtures of odor molecules. The results, published in the journal Science , showed that the nose can smell at least one trillion different scents.
Researchers explain that scents enter the nose and travel up the nasal cavity to the olfactory bulb, where many olfactory nerves are located. There, odorants are detected by many different receptors located on nerve cells and send signals to the brain. The combination of activated nerves creates odors that humans can distinguish.
The nose can smell trillions of different scents. Photo: Freepik
Smell is the oldest sense.
Some discoveries of chemicals involved in scent suggest that smell is the oldest sense. Even some single-celled animals can detect chemicals in the environment through smell.
Women have a better sense of smell than men
Women have a better sense of smell and odor recognition than men. Experts believe this is because women have a more developed prefrontal cortex.
Each person has a unique smell.
Like fingerprints, each person has a unique scent. The characteristic scent comes from a gene that determines tissue type. However, this is often not the case with identical twins. Dogs can tell fraternal twins apart, but not identical twins apart based on smell.
Loss of smell can warn of certain diseases
A reduced sense of smell could be an early sign of Alzheimer's or Parkinson's disease. This is because a reduced ability to perceive scents is linked to a loss of brain cell function, which is a warning sign of the risk of developing these two diseases.
Bao Bao (According to Everyday Health )
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