When a "needle" pokes into your skin, you feel nothing and may even feel a little itchy. Yes, it was done by the mosquito you hate most. Today I’d like to talk to you about how the mosquitoes that you hate so much use exquisite blood-sucking methods to make you bleed painlessly.
Question, where in the world do human babies cry the most? There is only one answer, and that is the injection room of the hospital's pediatric department.
Whether it's an infusion needle or a syringe, as long as this bright thing is shown, it will definitely make every child cry. After all, in the millions of years of human evolution, we can immediately feel danger when we see needles and sharp things, so the fear of needles can be said to be engraved in human genes. But there is one exception.
When a "needle" pokes into your skin, you feel nothing and even feel a little itchy. Yes, it’s the mosquito you hate most.
After the mosquito sucks blood, it will leave you with almost no pain except for leaving you with an extremely itchy bag. The same "needle" is used to pierce the skin, so how do mosquitoes suck blood painlessly? In order to answer this question, many scientists are studying mosquitoes and trying to develop needles that look like mosquito mouths. Hello everyone, I am a bad reviewer. Today I will talk to you about how the mosquitoes that you hate so much use exquisite blood-sucking methods to make you bleed painlessly.
# How do mosquitoes suck blood painlessly? If you do catch a live mosquito, you will find that its needle is so soft that it is impossible to pierce it into the skin no matter how hard you try. Because mosquitoes do not directly pierce the skin with their mouth needles, they have a special blood-sucking technique. Mosquito Mouthpart Structure This is a Culex mosquito, the mosquito that bites you most often.
From the outside, the mosquito's mouthpart does look like a needle, but its actual structure is very complex, and it looks more like a shield machine. What we can see is the mosquito's lower lip, which looks like a scabbard and contains six needles.
A pair of upper jaws, a pair of lower jaws, an upper lip, and a tongue. The front part of the mosquito's lower jaw is serrated, which is soft on the inside and hard on the outside. The closer to the tip, the higher the surface hardness. It is responsible for stabbing and sawing the skin, while the upper jaw is very sharp and is responsible for cutting the skin. The tongue is responsible for injecting saliva, the upper lip is responsible for sucking blood, and the "scabbard", the lower lip, is responsible for guiding the position and opening the wound.
So the mosquito is not biting you with a needle, but using a "6+1" configuration to suck your blood. How do mosquitoes suck blood? Today, this Culex mosquito stopped on your body again and decided to suck some blood, but this process is not easy.
First, the mosquito will tighten its mouthparts and create a dynamic impact on your skin. At this time, the "Six Meridians Divine Sword" wrapped under its lower lip will be unsheathed collectively, and the upper jaw will be attacked first. This needle has the sharpest tip, like a foil sword piercing your skin, and then the mandible with a serrated tip, which is responsible for sawing through the skin, allowing the mouthparts to continue to penetrate deeper.
At this time, looking from the outside of the skin, the mosquito's lower lip is curved into an arch, and the lower part is close to your skin. While it opens the wound, it guides the other mouthparts to find blood vessels, just like the left hand holding a nail, providing guidance for the right hand where the hammer should fall.
But the mosquito cannot find blood vessels 100% of the time, so its upper and lower jaws are like a Swiss Army knife, using a frequency of 10-15hz to repeatedly pierce and cut, wandering between your skin and flesh, looking for suitable capillaries. This biting process may even last several minutes. Finally, the mosquito found the target blood vessel, and the two tubes in the center of the mouthparts, the upper lip and tongue, began to work.
The tongue is responsible for injecting saliva into your blood vessels. Mosquito saliva contains anophelin, which prevents blood clotting and allows blood to flow more easily. It also contains anesthetizing protein, which can reduce your skin sensitivity when sucking blood.
The last step of the mosquito's mouthparts is to suck blood. At this time, it is finally the upper lip's turn to work. Like the lower jaw, it is soft on the outside and hard on the inside. The closer to the tip, the higher the surface hardness. It is responsible for inserting into capillaries and transporting fresh blood out.
When a mosquito sucks too much blood, its abdomen will swell to be larger than itself. At this time, it will separate the water in the blood and make room to store more nutritious red blood cells. The entire blood-sucking process takes almost 240 seconds. Even under interference-free conditions, there is a half chance that mosquitoes will not be able to suck blood.
But the Culex mosquito in your home is lucky. Before you found it, it sang a little song and left. The saliva it leaves behind will be recognized by your immune system as a "foreign virus" and start an immune war.
The functional proteins in mosquito saliva will bind to sensitized cells under the skin and mucous membranes, causing the cells to release histamine and other substances, causing skin redness, edema, and itching.
So the essence of the mosquito bag is an allergic reaction. If someone is bitten by a mosquito for a long time, his immune system will be able to ignore the protein in the mosquito's saliva, and he will not develop bites in the end. But in fact, most people have not been bitten enough, so it is difficult to be immune to mosquito attacks. Mosquito saliva will not only make you bloat, but if the mosquito carries mosquito-borne pathogens such as malaria parasites, dengue virus, Zika virus, and Japanese encephalitis, the pathogens will also be mixed into the body with the saliva at this time.
Until now, more than 700,000 people still die from mosquito bites every year. #How to make needles with mouthparts like mosquitoes? After watching the mosquito's blood-sucking process, the mystery of its painless blood-sucking has been solved: first, its saliva with anesthetic, and second, its tiny but different mouthparts, and the way of vibrating penetration. Then some students asked, can humans make a needle that resembles the mouthparts of a mosquito, so that it can simulate a mosquito bite and make the injection less painful?
This has to mention microneedle technology. Inspired by the "painless blood-sucking" of mosquitoes, Japanese scientist Fumio Kamiyama developed an extremely fine injection needle with a diameter of only 60 microns. By arranging multiple such microneedle arrays, rapid delivery of drugs can be achieved.
This kind of microneedle is only a few hundred microns to a few millimeters long. It can pass through the stratum corneum of the skin without touching the pain nerve. It forms a drug delivery channel on the skin surface, allowing the drug to reach a designated depth of the skin and enter the subcutaneous capillary network for absorption. The drug penetrates without causing pain or skin damage. Microneedle technology can be said to be a technological leap in drug delivery and blood sampling. Especially for people with diabetes and other people who need long-term injections of drugs, they no longer have to endure the pain of injections. This feeling can only be described in one word, cool (Shen Teng)!
However, since artificial microneedles directly penetrate the skin, the penetration force is three orders of magnitude greater than that of mosquito stylets, and they are prone to buckling and breakage during the penetration process. Large-scale clinical application has not yet been achieved.
A V-shaped rib with a length of 20~25 μm can also be seen at the end of the mosquito's upper lip. This structure enhances the strength and stiffness of the upper lip, making it less prone to bending damage. This nature's design is much superior to all ordinary needle and microneedle designs. So from the perspective of the Creator, the bionic needles made with existing technology are just a poor imitation of the mosquito mouthparts.
In addition, the design of some medical equipment has also learned from the mouthpart structure of mosquitoes, such as biopsy needles. A biopsy is the most common way to diagnose cancer. Doctors use a biopsy needle to collect a small piece of tissue, called a sample, from a suspected tumor. The pathologist will then look at the sample under a microscope to make an accurate diagnosis. However, the biopsy needle may cause tissue damage, deformation, movement and other problems during the insertion process.
It not only affects the accuracy of diagnosis but also may cause trauma to the patient. Especially for brain tissue, even minor trauma may cause irreversible brain damage, so the medical community has been eager to have a biopsy needle that will not cause tissue damage. In 2017, four Temple University scientists developed a bionic surgical needle that borrowed the serrated structure of a mosquito's jaw.
They tested on bovine brain and bovine liver and found that the needle with this special structure was more efficient. Compared with ordinary needles, the serrated needle reduced the resistance by about 10-25% when piercing the bovine brain, and reduced the resistance by 35-45% when piercing the beef liver. This also means that this biopsy needle has less resistance when it is inserted into the skin, causes less deformation to the tissue during the insertion and extrusion process, and is less likely to cause displacement.
Just last month at the World Artificial Intelligence Conference, the State Key Laboratory of Sensing Technology at the Shanghai Institute of Microsystems, Chinese Academy of Sciences, demonstrated a bionic flexible neural probe that they developed similar to mosquito mouthparts. Simply put, it is an invasive brain-computer interface that can be used for clinical research, monitoring and treatment of brain diseases such as epilepsy, depression, and ALS.
This mosquito-like bionic neural probe imitates the unique structure of the mosquito's lower jaw and upper lip - a hard outer rod on the outside and a flexible straw on the inside - the hardness of the outer rod ensures implantation, while the flexible straw can be retained in the body for collection. The hardness of the outer shell can even directly penetrate the dura mater. Compared with traditional brain-computer interfaces, which require cutting open the dura mater and then implanting it, it is more convenient, and the electrodes will not be damaged during the penetration process.
The highly sensitive tactile sensor array behind the probe has also learned how mosquitoes use touch instead of vision to locate, and can accurately distinguish whether the probe touches brain tissue or blood vessels, thereby avoiding blood vessel damage.
Humans have been studying the bionic principle of mosquito stylets for hundreds of years. The next difficulty lies in micro-nano manufacturing technology and cost reduction. Although we all hate mosquitoes, countless scientists are working hard to imitate mosquitoes, so that one day our injections or surgeries will be as painless as mosquito bites.
Although our imitation of nature's exquisite design is still poor, this cannot stop humans from understanding and learning from it until we become our own creators.