How many olfactory receptors does our nose have?

There are a total of 10 million olfactory receptors, known as olfactory cells, on both sides of the nose. It is distributed on both sides than the septum and the middle turbinate to form an olfactory fissure, with an area of 5 square centimeters. Each olfactory cell has 1000 cilia, which increase the receptive area of the receptors.

Yes, the range of 5 square centimeters used to be as large as 600 square centimeters.

Consultant ENT Specialist Pang Yuk Tin pointed out that the loss of smell is often not an independent condition, but is caused by an accident such as a strong impact or a certain disease.

Since the sense of smell disappears completely only when both the right and left olfactory nerves are damaged, in most cases it is a partial loss of smell. In addition, loss of smell tends to happen gradually, so patients usually do not feel very alarmed, and some even suddenly realize that they have been unable to smell for a long time when the doctor asks them.

Dr Pang Yuk Tin said there was no need to be too alarmed by the public, as loss of smell caused by brain tumours is not very common.

He also revealed that there are not many medical studies that treat the sense of smell as an independent pathology, because most patients only partially lose their sense of smell, but not completely. Apart from the identification of poison gases, the loss of smell itself is not a danger to the patient's life.

However, the patient's quality of life may be greatly affected by the loss of smell. In addition to not being able to perceive various aromas, 90% of the taste comes from smell, so people who have lost their sense of smell will feel 'tasteless' when eating. ”

He said: "Smell is the passage of some airborne molecules into the nose and the transmission of olfactory information to the olfactory nerve fibers in the form of radio waves, which in turn transmit the information to the brain. ”

According to Dr Pang, there are three main causes of anosmia: blocked nose, damage to the olfactory nerve or damage to the brain.

How we feel the taste.

He pointed out that if there is a tumor inside the nose, or if it becomes swollen due to inflammation or sensitivity, causing the nose to be blocked, the smell cannot reach the olfactory nerve fibers, so there is no sense of smell, and the effect is generally short-lived.

A tumour in the brain or a mental illness can also cause the patient to smell things but not feel the smell, or the sense of smell is distorted. The former is a physical disease that can be removed by cutting the tumor**, while the latter requires the use of long-term psychological counseling and psychiatric ** to remove the false hallucinations of the patient's sense of smell.

However, Dr Pang pointed out that once the olfactory nerve is damaged, the patient may lose his sense of smell permanently.

The olfactory nerve is the specialized sensory nerve of the sense of smell. Nerve fibers travel from olfactory receptors in the mucosa at the top of the nose through a small hole in the skull, connect with the olfactory tract, and travel posteriorly back to the brain. When a patient has an accident and the inside of the brain is affected, the tiny olfactory nerve fibers may be partially or completely severed.

According to Dr. Peng, if the olfactory nerve is only partially severed, the patient must see a doctor within a week or two of the olfactory nerve damage**, if it is too late, the olfactory nerve may be permanently damaged and cannot be remedied.

Doctors usually ask the patient about the medical history and the gradual loss of smell, and then use the endoscope to gain insight into the "condition" inside the nose.

In **, the doctor is mainly based on the patient's underlying condition**, except for the case of olfactory nerve damage, the doctor rarely specializes in **anosmia. **Methods vary depending on the disease and include medications, surgery, counseling, etc.

The correct answer is 5 million olfactory receptors.

Question 1: Is the human olfactory receptor an internal receptor or an exoreceptor Personally, many people think that the air is inhaled into the body before people have a sense of smell, but in fact, people who have studied anatomy know that the olfactory receptors olfactory filaments and olfactory bulbs are actually directly exposed to the nasal cavity. , which is in direct contact with air.

Therefore, it can be considered as an exoreceptor.

Question 2: What are human odor receptors called Olfactory receptors are located in the upper nasal passages and the middle and upper part of the nose, the olfactory epithelium is composed of olfactory cells, Sertoli cells, basal cells and Bowman's gland, and olfactory cells belong to neurons. The suitability of olfactory receptors ** is that the chemicals in the air file the stagnation, the substance molecules are absorbed by the mucus of the olfactory epithelial part, diffuse to the cilia of the source chakra olfactory cells, and bind to the specific receptors on the cilia surface**, this binding can cause the production of second messengers (such as CAMP) through the G-protein, and finally lead to the opening of voltage-gated Ca2+ channels on the membrane, Na+ and Ca2+ flow into the cell, causing depolarization of cytoreceptor cells, and diffusion to the axial thalamus of receptor cells in an electrotense manner. Action potentials are generated, which travel along the axon to the olfactory bulb and then to the higher olfactory centers, giving rise to the sense of smell.

There are about 2,000-4,000 scents that humans can discern. It is thought that the receptors for different olfactories may be formed by a combination of at least seven basic odors: camphor, musk, floral, ether, mint, pungent, and rancid.

Each olfactory cell responds to only one or two particular odors. The sense of smell has a threshold, and at the same time, the sense of smell adapts quickly, and when a certain gas suddenly appears, it can cause a pronounced sense of smell, but if the substance continues, the sensation will quickly diminish or even disappear.

<> "How many kinds of high-lead smells can the human sense of smell distinguish?

A: "It varies from person to person, but for some people, it is enough to be able to distinguish the smell of shi and rice. Qi Que is good".

In our daily lives, we often smell a variety of smells, which are somewhat similar, but if the nose is sensitive enough, it can still distinguish them. How many kinds of qi can the human sense of smell distinguish? Studies have found that ordinary people can basically distinguish more than a dozen different scents, and can distinguish more after training, while highly trained perfumers can generally distinguish and memorize more than 400 odors, and excellent can remember about 3,000 old scents.