Post: When you get caught by a mosquito

When you get caught by a mosquito

Fang zhouzi 20:10:26
Http://fangzhouzi.blog.hexun.com/76466526_d.html

The weather is getting warmer and mosquitoes are getting warmer. Unfortunately, I am a special mosquito recruit, especially every time I go back to my hometown in the South, I always suffer from the bites of several mosquitoes, and the response is fierce. When I get a bite, I often have a big bag, after several days, the mark remains.

Why do people in the same room become mosquito food while others are safe? To answer this question, we first need to know how mosquitoes discover people, or how they attract mosquitoes. Most of the head of a mosquito consists of eyes with hundreds of small eyes. However, the mosquito does not rely on its eyes to find people, but on "Chemical instruments" to detect the flow of carbon dioxide and heat in the air, to find a living person breathing in the distance and then fly to him. Even if you are hiding in a closed room, mosquitoes can easily find gaps and air holes to drill in, because the carbon dioxide that you call out flows out of these exits and you have already told where the mosquito entrance is.

However, carbon dioxide can attract mosquitoes to people, but it does not help mosquitoes find their mouths-bare skin, especially the skin on the feet, but also the favorite of some types of mosquitoes. Mosquitoes rely on sweat to find their mouths. Fresh sweat is tasteless. The various bacteria living on the skin break down the nutrients in the sweat to release the taste. Different species of bacteria break down the sweat and produce different components. They make different flavors (more specifically, they are Volatile gases) and have different attractiveness to mosquitoes. Some bacteria also exist in the environment, while some bacteria almost only live on the skin. The latter is the best sign of the skin and is the most interesting of mosquitoes. The composition of bacteria living in different parts of the body is also different, and mosquitoes can find their favorite foothold accordingly.

The lactic acid, ammonia, carboxylic acid and other components in sweat are the ingredients that attract mosquitoes. The bacteria on different human skin are different, and the composition of sweat is also different, this leads to a difference in their attractiveness to mosquitoes. Some human sweat also contains mosquito-annoying ingredients, such as aldehyde, xinaldehyde, nonaldehyde and some ketone which are natural mosquito repellent agents. In particular, when the two ketone compounds in sweat are mixed in a ratio, the mosquito repellent effect even exceeds the DEET standard, which is regarded as the mosquito repellent agent ). So some people are not afraid of mosquitoes because their bodies are constantly making and releasing the strongest mosquito repellent agents.

When a mosquito is biting, it needs to inject several proteins into the human body, collectively referred to as the mosquito saliva protein. These proteins inhibit the blood coagulation system of the human body, prevent blood coagulation, prevent vascular contraction, so that mosquitoes can smoothly suck up the blood. After sucking blood, the mosquito flew away, but the mosquito saliva protein remained in the human body. The body's immune system was mobilized to try to clear these foreign substances and an immune response occurred. In this process, a substance called amine is released, which can expand the capillary, increase the permeability of the vascular wall, and fill the cells with liquid, resulting in inflammation. At this time, the place where the mosquito bites is itchy, red and swollen.

If mosquitoes do not carry pathogens, the point of blood sucked by mosquitoes is negligible. What makes people uncomfortable is the itch at the bite. This is because the human immune system does not have to make a big fight against the mosquito saliva protein, but it is actually an allergic reaction. There are three types of allergic reactions caused by mosquito bites. Some of them are very fast. They appear after being bitten for a few seconds, but they disappear quickly and disappear after a day. Some of them only appear one day later, it lasts for several days or even many days.

The allergic reactions caused by different species of mosquitoes are not the same, and some are light. Similar to other allergens, different people have different levels of reaction to mosquito bites. Some allergies are very serious, even serious, and cause a fatal risk. Some others have very mild allergies, light to no attention. Some people feel that they are not looking for mosquitoes. They are not allergic to the bite of a certain type of mosquito. They are unknowingly sucked away by mosquitoes. They are not infected by mosquitoes.

Once allergic to a place bitten by a mosquito, it may itch, making people unable to help but scratch it. As a result, it will stimulate the secretion of more histines, so it is often more and more itchy and swollen. Many people are bitten by mosquitoes. They are used to coating such oil as oil and wind oil. In fact, they stimulate capillary expansion and make allergies more serious. On the contrary, it is cold applied to the bite, which can promote vascular contraction and relieve allergic symptoms. If the allergy is serious, you can consider taking antiamine antiallergic drugs, such as chlorpheniramine, phenhydramine, and xianterming. They are all used to inhibit the allergic reaction. It can also be used in the red and swollen areas to apply cortex steroid hormones (such as hand, hand, to the vascular contraction of the inflammatory area and to reduce the capillary permeability reaction. Of course, in general, there is no need to use drugs, so you have to endure. Perhaps a little comforting is that, if you have been living in a certain place for a long time, you may gradually desensitize it, and your allergies may become less serious. It is said that the host is desensitized by mosquitoes.

2012.5.2

(Xinhua Daily Telecom, 2012.5.4.)