The sense of smell

Most often people percieve that the eyes and ears are the most vital organs if we are to consider the senses. But did you know that the sense of smell is probably the oldest of our five senses. As you breathe in, air passes through a cavity behind the nose. It contains patches of millions of cell receptors called olfactory cells.

Sensory hairs stick out form the surface of these receptor cells. The hair detects smells and pass information along nerve fibres to the brain. Substances that you recognize as having odour dissolve in the layer of mucus covering the sensory cells, stimulating them to produce a signal.

Most people are able to detect about 4,000 different smells. However, people whose work is based on their ability to smell, such as chefs, perfume makers and wine tasters can distinguish as many as 10,000 different smells.

The human sense of smell is very poor compared to that of animals such as dogs. Some dogs are able to identify and follow the smell of a person's perspiration, even though it may be several days old. These so called sniffer dogs are often used to find people buried beneath an avalanche or in houses destroyed by earthquakes. The can identify just a few molecules of human perspiration.

It would have been wonderful if human beings would have the same sense of smell. I was wondering if there is a way to improve the humans sense of smell... Can this be developed. Well, having such a great sense of smell would surely help us in many ways.