There is an important specialty in the olfactory nerves that differentiates them from the other kinds of neurons. While the hundreds of billions of neurons in our brains do not renew themselves instead staying the same throughout all of our lives, the millions of olfactory cells in our nose live approximately 45 days. After this time, new cells replace the dead cells. The place where the new olfactory cells are built is in the basal cells in the olfactory region. Basal cells produce the cells continually with great order and they work like an olfactory cell production factory.
Be aware that approximately in every 45 days, millions of your olfactory cells change completely, however, you continue to smell the scent of a rose as a rose and the scent of an orange as an orange. If there is an error during the handover of the olfactory cells, you may smell many of the scents wrongly or cannot smell any scent altogether. Because there will be no possibility to correct an error like that, your smelling sense will deceive you constantly and will be a source of great burden to you. However, this kind of thing never happens by the permission of Allah and the new olfactory cells continue with their duties perfectly.
Without a doubt, all of these things are one of the proofs of Allah’s faultless creation Who is the Owner of an infinite wisdom and power. Every part, every cell, every molecule and every atom which form the smelling system acts in a way which Allah inspires in them, from the first day of their creation. Allah tells each one of them in detail how to act in every moment. This truth is stated in a verse of the Qur’an as thus:
It is Allah Who created the seven heavens and of the earth the same number, the Command descending down through all of them, so that you might know that Allah has power over all things and that Allah encompasses all things in His knowledge. (Surat at-Talaq, 12)
During the day we breathe air from our nose. While our nose transforms the air inhaled into a most proper state for our lungs, it also directs some of this air into the smelling region of the nose, so that we can smell at the same time. Most people do not know that he or she owns an incredible chemical analysis facility. This facility is placed in the smelling region of our nose and works nonstop like a chemical factory to analyze the smells around us. While we perform our daily routines, not showing any extra effort for smelling, this facility is in operation. Even at night during our sleep, it can detect a harmful smell like smoke and warn us. This facility is such an unparalleled creation that it can recognize more then ten thousand different scents and works with a perfect accuracy rate and sensibility.
Some cells in our sensory systems
As we can see, every sensorial cell has a special configuration. Olfactory cells consist of three main parts. In the middle part is the cell body, which has platelets called cilia on the one end and an extension called axon on the other end.
The place of the olfactory bulb in our skull and details of its structure
The system in the olfactory bulb is very complex. In the side figure there are only two types of olfactory cells which have different receptors shown (Brown and Blue), two glomerulus and a couple of cells. Keep this in mind, the smelling system consists of tens of millions of olfactory cells, thousands of different smell receptors, two thousand glomerulus, tens of thousands of mitral cells, clumped cells, granule cells and periglomerular cells. If this truth is taken into account, the complexity mentioned here can be better understood.
Another amazing point about our smelling system is that the new olfactory nerves are able to find their way to the olfactory bulb without any error. There are no directional signs in our nose or brain. There are also no questions for the new cells to ask about their way or to learn it. It is not possible to explain the lifelong and faultless renewal process in our olfactory nerves by using calculation of probabilities. There is no distinction between the claim that the building of the connections between the millions of olfactory nerves are coincidental or the similar claim that the cables which constitute the telephone system of a big city like Istanbul of having been laid without a fault by the winds, lightnings and coincidences. Without a doubt, all of these things are the proofs of Allah’s perfect creation, Who has infinite wisdom and power.