Many people like to play in rural rivers or streams every summer, but we often encounter some scary animals, such as: , leeches , snakes and so on.
Compared with snakes, leeches are more concealed and less noticeable. They always bite people silently, and they also suck blood. It is precisely because of this special skill that people are deeply impressed, staying away, and even become a shadow of many people's childhood.
According to legend, some tropical countries will use a special penalty: fill a pool with leeches, then take off the clothes of the punished person, and then soak in the pool for three days and three nights. If the person who was punished did not die as a result, the previous grievances and faults would be wiped out. However, most people cannot survive.
This is just the leeches sucking blood on the surface of the human skin, then the problem is, if a person eats leeches by mistake, causing the leeches to enter the human body, or the leeches happen to enter the human body, the leeches will be in the body. Do you breed and suck blood? Will people die because of this?
To understand this problem, we must first start with the habits of leech.
The habits of leeches
The leeches include 35 span1 _span strong span3 _span3 strong span3 _span3 _span3 strong span 35 _span _span strong 35 strong span _span 35 _span strong span _span3 _span3 strong span 35 _span _span _span strongThe specific classification in biological taxonomy is: animal kingdom-annelid phylum-ring band class-hiru subclass, which belongs to hermaphrodite . In the Annulus class, in addition to leeches, there are also oligochaetes, such as: earthworm . In other words, leeches and earthworms are considered close relatives. Their characteristic is that they have a ring like a "collar" on their bodies. However, leeches and earthworms are also very different. The outside of leeches is hairless, and at the same time The body is stronger.
Scientists have discovered about 700 species of leeches, of which about 100 species live in the ocean, about 70 species live on land, and the rest are all Live in freshwater environments, that is, creeks, ponds, freshwater lakes, etc.
Most people think that leech mainly sucks human blood, but in fact this is a misunderstanding of leech. The leeches are actually carnivorous animals, mainly capturing small invertebrates for a living.
In this big family of leech, only a part of leech adopts: temporary parasitic . The so-called "temporary parasitism" is: Only when the leeches are feeding, they will temporarily contact the host's body surface .
and among these leeches,Most of them depend on the body fluids of various hosts for food, and only a small part of them live by sucking the blood of mammals, and it is precisely this category that has left a deep impression on humans. However, we can also see from this that leeches cannot enter the human body to parasitize, but only temporarily parasitize on the surface of the human body. How do they parasitize on the surface of the human body?
The head and tail of the leeches have a suction cup that can help them stick to the surface of human skin. At the same time, leeches are also divided into two groups, namely: " with kissed leech " and " without kiss leech ". Snout leech refers to the muscular mouthparts in the pharynx of the leech, which is also called: .
When the leeches are adsorbed on the surface of the human skin, the snout can protrude from the leeches’ mouth, pierce into the human body, and suck blood. But this does not mean that kissless leeches cannot suck blood. Some kissless leeches have three semi-circular jaws (some have only one or two) in their mouths, which can be used to cut the skin and suck blood.
When leeches suck blood, they also secrete anticoagulant factor ,There are many kinds of anticoagulant factors: antithrombin and hirudin . These antithrombin enzymes will make the wound bleed continuously, which allows the leech to continue to suck blood until it is full. Generally speaking, the amount of blood sucked by a leech is quite large, and it is probably able to suck 2-10 times the amount of blood of its own body weight. From the time of ancient Greece, some people used leeches for bloodletting therapy. This method lasted for thousands of years, but later proved to be useless at all.
Many people may find that it is difficult to detect when they are sucked blood by leeches. Could they also secrete anesthetic factors?
Scientists have been wondering whether it is because leeches will release anesthetic factors when they suck blood, which makes it difficult for people to find them. However, after a detailed study, it was discovered that there was no anesthetic factor. Scientists speculate that it is not easy for people to find them because the skin of people's legs is not sensitive enough, and the surrounding environment, water pressure and temperature, etc., distract attention and make it difficult to detect leech.
Can leeches survive in the body?
I believe that some people have seen such a report:
Some people once found a large number of "leaches" in the stomach of cows.
Objectively speaking, this report is problematic. The cow’s stomach contains other parasites, not leeches. We must know that the digestive capacity of the cow’s stomach is super strong, and it is difficult for ordinary parasites to survive here.Only those parasites that have evolved symbiosis with cattle for a long time will work, and leeches are not. The leeches are actually unlikely to survive in the cow's stomach. This is because leeches need to breathe, but they do not need to pass through the lungs like humans, but rely on the body surface to breathe.
If the leech accidentally enters the human body, if it is completely hypoxic, such as in the stomach and intestines. Then the leech will die because it cannot breathe. Of course, this type of leech is actually "temporary parasitic".
There are special cases in everything. There are also parasitic leeches in this big family of leeches. They also like to live in fresh water, and they are much smaller than ordinary leeches. If the fresh water in the wild is drunk directly without boiling, it may cause the leeches to enter the body to parasitize. Such parasitic leeches include nasal leeches, Nile leeches, and granular cow leeches. However, even for these parasitic lees, they usually choose to parasitize in those semi-open places, such as the nasal cavity and throat.
In addition to parasitic leeches, other leeches living in fresh water have also crawled into the nasal cavity, throat and even lungs. In addition, in some special cases, leeches have penetrated into the human reproductive organs, even the uterus. But you will find that these are basically semi-open parts. Up to now, there has been no case of leech crawling into the human intestines and stomach. Objectively speaking, leeches are also unlikely to survive in the stomach. Therefore, even if someone wants to swallow the leeches directly, the leeches will basically not enter the stomach and intestines, but rely on their own suckers to adsorb to the throat. Even if it actually enters the stomach, it cannot survive, not to mention other life activities.
Summary
Through the understanding of leeches, we must pay more attention when we are in the wild, especially when we use fresh water in the wild, we must grill the water. When washing your face and bathing with fresh water in the wild,Also pay special attention. After all, the parasitic leeches may actually get into the nasal cavity and throat.
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