MODULE 2 Physiology of Olfaction Olfactory receptors have olfactory hairs that are embedded in the mucus layer. Olfactory hairs are protrusions from the dendrites, while the other ends are axons that form synapses with other nerve cells in the olfactory bulb (brain). In the olfactory hairs there are odor receptor proteins. The smell of chemicals that are inhaled with the air (in the form of gas) does not rise directly to the olfactory bulb, but diffuses in the mucus layer and binds to receptors on the dendrites. In the brain, odor information is processed or translated to give rise to the sensation of smell. The brain can remember certain smells because the olfactory tube is directly connected to the emotional and memory centers in the brain. For example, when we smell a certain perfume we will remember someone who has worn that perfume. 1. Nostril Every human being has two nostrils normally, where the nostrils are connected to the nasal cavity. In the nasal cavity there are nasal hairs and also mucous membranes, whose function is to hold various dirt that enters the nose, specifically when breathing. If a fatal accident occurs which causes the nostrils to become less open, it will result in a person lacking oxygen due to difficulty breathing, therefore plastic surgery is usually performed. 2. Nasal cavity Second after the nostrils, there will be the nasal cavity (as discussed above), the nasal cavity itself has the most superior function in the human respiratory tract. And lined with olfactory cells and olfactory receptors. Next is the respiratory area, this area in the nasal cavity is the largest part, lined with psudeostratified ciliated epithelium. And inside the epithelium is interspersed with mucus goblet cells. Finally, in the nasal cavity there is the vestibule which refers to the area around the external opening to the human nasal cavity. 3. Smell nerve cells The reason why a person can feel odors or fragrances is because there are odor nerve cells in their sense of smell. Nerve cells in the nose are responsible for capturing chemicals in the air. For your information, odor nerve cells have fine hairs, where these fine hairs are connected to the nerves, and also unite into the olfactory nerves that go to the brain. The smell nerves in the human nose are located in the section mucous membranes present in the upper nasal shell, middle nasal surface and upper nasal cavity. 4. Sine The next part of the human nose is the sinus. Sinuses are 4 cavities that have different locations around the nasal area. The sinuses are located in the side and upper cavities of the nose, and have been formed since a person was first born. Meanwhile, in the forehead cavity, sinuses do not appear until a person reaches the age of 7 years. 5. Cartilage You've probably seen boxing on television, and why boxing rules prohibit people from punching in the nose area. This is because the nose is formed from a collection of cartilage, which is flexible, so it must be protected. Cartilage also has another name, cartilage. 6. Separator (septum) In the human nose, there is also a septum. The septum is what separates the nose into 2 cavities, which are formed stretching from the nostrils to the back of the throat. 7. The way it works is that someone can smell the smells Actually, the working principle of someone being able to smell various odors is very simple. If an odor enters the nasal cavity through the nostrils, the odorous gas or vapor will provoke stimulation, which then continues to the olfactory nerve, then continues to the brain for translation. 8. The function of the nose is to warm the air The nasal cavity experiences natural enlargement, this natural enlargement will warm the oxygen entering your nose. Of course, these blood vessels will expand and contract naturally, based on the surrounding air temperature as well.