Simple common sense of poisonous snakes
A poisonous snake, with a triangular head and poisonous glands, can secrete venom. When a poisonous snake bites a person or an animal, the venom flows out of the fangs, poisoning the bitten person or animal. Viper, viper, etc. are poisonous snakes. Venom can be used as medicine.
Of the 3,000 species of poisonous snakes in the world, only about 15% is considered to be toxic to human beings. About 25 species of snakes in the United States are poisonous snakes or poisonous saliva secretions. Except Alaska, Maine and Hawaii, poisonous snakes in other states are all local. Although more than 8,000 people are bitten by poisonous snakes every year in the United States, less than 6 people die every year, most of them are children, the elderly, followers of some religious sects who play poisonous snakes, and people who have not been treated or treated badly. Most of them were bitten by rattlesnakes, and almost all the deaths were caused by rattlesnakes. Most of the snakes bitten by other poisonous snakes are copper-headed snakes, and a few are cotton-billed snakes (a fish-eating snake in water). Coral snakes account for
Snake venom physics
Snake venom is a complex substance, mainly protein with enzymatic activity. Although enzymes play an important role, some of the more important snake venom may be peptides with smaller molecular weight. Most of the components of snake venom seem to bind to various physiological receptors of the victims, so it is superficial to arbitrarily divide snake venom into neurotoxin, blood toxin and cardiotoxin, which may lead to errors in clinical judgment.
The venom of most North American pit vipers (rattlesnakes) contains toxic protein components which can cause local and systemic effects. These effects can lead to local tissue injury, vascular injury, hemolysis, disseminated intravascular coagulation (DIC)-like (defibrase) syndrome (see below) and lung, heart, kidney and neuropathy. Rattlesnake venom can change capillary permeability, and then make electrolyte, colloid and red blood cells overflow through the blood vessel wall to the bitten site and other organs (such as lung, kidney, heart and rare central nervous system). At first, it was edema, hypoalbuminemia and blood concentration. Later, blood and body fluids are concentrated in microcirculation, leading to shock, hypotension and lactic acidemia. Decreased effective circulating blood volume will increase heart and kidney failure. In the case of severe rattlesnake bites, thrombocytopenia (platelet count
Proteinuria, hemoglobinuria and myoglobinuria can be seen in the white-headed bamboo. The venom of most pit vipers in North America only causes slight changes in neuromuscular conduction, while the venom of Mojave and eastern diamond rattlesnake can cause serious nerve damage.
The venom of coral snake (cobra) mainly contains neurotoxic components, which can cause neuromuscular block. Due to the lack of obvious proteolytic enzyme activity, the symptoms and signs of the bite site are mild.
symptom
Types of snakes Most local symptoms and signs of Agkistrodon buccal bite are obvious burning pain and edema (usually within 10 minutes, rarely more than 30 minutes), and erythema and ecchymosis appear in the bite site and adjacent tissues. Without treatment, edema will develop rapidly and affect the whole limb within a few hours. Regional lymphangitis and swollen and tender lymph nodes may appear, accompanied by an increase in body temperature on the surface of the injured part. In moderate or severe rattlesnake bites, ecchymosis is more common, appearing in the bitten area within 3~6 hours after the bite. Most of them are very serious after being bitten by diamond-shaped back rattlesnakes and rattlesnakes in grassland, Pacific Ocean and Woods. But being bitten by a copper-headed snake and a Mohavi rattlesnake is not serious. The skin will be tight and discolored; Herpes usually appears in the bitten area within 8 hours and often bleeds. These changes are usually superficial, because rattlesnake bites are limited to skin and subcutaneous tissue. If left untreated, necrosis around the bite is common, and thrombus may form in the superficial blood vessels around it. The peak of most snake venom actions occurs within 4 days after bite.
Systemic symptoms include nausea, vomiting, sweating, fever, general weakness, paresthesia, spontaneous muscle contraction, mental state change, hypoxemia and shock. Rattlesnake bites smell like rubber, mint and metal. Mojave rattlesnake bites can cause respiratory depression. Rattlesnake venom poisoning can cause many coagulation abnormalities, including prolongation of prothrombin time (measured according to the international normalization ratio) or partial thromboplastin activation time (aPTT), thrombocytopenia, hypoproteinemia, increase of fibrin degradation products, or the syndrome similar to disseminated intravascular coagulation (defibrase) with the above changes. Bleeding can occur at the bitten part or mucosa, accompanied by hematemesis, melena and hematuria. In most cases, the obvious increase of hematocrit is an early phenomenon secondary to blood concentration, and then it can be reduced due to blood loss caused by fluid replacement and coagulation disorders. In severe cases, hemolysis can rapidly reduce hematocrit. When bitten by a coral snake, the pain and swelling are mild or nonexistent, and are usually short-lived. Systemic symptoms can be delayed to 8~24 hours, and abnormal sensation around the wound and obvious limb fatigue appear within a few hours. Patients may have obvious weakness and lethargy, and their feelings may change, including euphoria and lethargy. Neuroparalysis may also occur, including ptosis, diplopia, blurred vision, dysphonia, dysphagia and salivation. Then respiratory distress and muscle twitching may occur. Once the nerve effect of coral snake venom poisoning appears, it is difficult to reverse it with antivenom drugs. Although given treatment, it can last for 3-6 days and the patient died of respiratory failure.
The severity of snake venom poisoning depends on the size and type of snake, the amount of snake venom injected, the number of wounds, the location and depth of bite (for example, head and body bites are more serious than limbs bites), the age, weight and health of the bitten person, the time between being bitten and starting treatment, and the sensitivity (reaction) of the bitten person to snake venom.
In the literature, snake venom poisoning is sometimes classified by numbers, but it is more practical to classify it into light, moderate and severe according to local changes, systemic symptoms and signs, coagulation parameters and other experimental results. The classification of snake venom poisoning should be based on the most serious symptoms or signs or experimental results. Venom poisoning can quickly develop from mild to severe, so it must be constantly reassessed. The tooth marks of poisonous snakes can indicate the species of poisonous snakes, but they cannot be used as positive identification. Typical tooth print patterns based on snake jaw anatomy have not been found in the field. Rattlesnakes can leave 1 or 2 tooth marks or bite marks; Single tooth marks are common. Non-venomous snake bites usually have multiple tooth marks.
There are more than 40 species of poisonous snakes in China, most of which are distributed in the vast provinces south of the Yangtze River. Snake venom can be divided into three categories according to its nature: neurotoxicity, blood circulation toxicity and mixed toxicity.
Silver ring snake, silver ring snake, sea snake, viper, etc. It mainly contains neurotoxins. Viper, pointed nose,
Bamboo leaf green and so on mainly contain blood, with poison. Cobra, king cobra and viper mainly contain mixed poison.
Nowadays, more and more people like outdoor activities, but they often underestimate the dangers in the wild, especially those caused by animals and plants. These dangers, especially poisonous snakes, are the most representative.
It is very necessary for everyone engaged in outdoor activities to have a correct and comprehensive understanding of poisonous snakes and understand the prevention and treatment of snake injuries.
Distinguish between poisonous snakes/nontoxic editors
Snakes can be divided into poisonous snakes and non-poisonous snakes. It is very important to distinguish between poisonous snakes and non-poisonous snakes when catching snakes. For example, if a person who is not ruthless in catching snakes finds a snake, he can immediately catch it with his bare hands, even if he doesn't catch it well, he will be bitten. If you recognize a poisonous snake, especially a poisonous snake, you can never catch it with your bare hands. You must catch it with a snake trap. A truly experienced person can tell whether a snake is poisonous or not just by looking at its appearance or a short section. How to tell? First from the appearance, then from the ecological situation, and finally from the structure of fangs to distinguish. Of course, the distinction between appearance and shape is not absolute, and there are exceptions. Distinguishing whether there are fangs is the most accurate method.
1. Judging from the shape of the head of a snake, the head of a poisonous snake is generally triangular, such as Agkistrodon halys and tortoise shell snakes. But there are also a few poisonous snakes, such as silver ring snakes, whose heads are oval.
The head of a non-venomous snake is generally oval, such as Zaocys and Rat Snake. But there are also a few non-toxic snakes, such as nuclear snakes, whose heads are triangular.
Judging from whether the stripes on the snake's body are bright or not, the stripes on the back of poisonous snakes are generally bright, such as Agkistrodon acutus and Bungarus multicinctus. However, there are also a few poisonous snakes whose back markings are not bright, such as the white-bellied cobra, which is gray and has no markings at all.
Non-poisonous snakes generally have inconspicuous stripes on their backs, such as Zaocys and Green Snake. But there are also a few non-poisonous snakes with bright colors on their backs, such as red chain snakes. More than 80 obvious red and black ring spots crisscross the sides of the body and are often mistaken for poisonous snakes.
3. Judging from the length and thickness of the snake's tail, the snake's tail is generally thick and short, but it suddenly tapers backwards from the anus, such as gorge snake and cobra. But there are also a few poisonous snakes with thin and long tails, such as silver ring snakes.
The tail of non-poisonous snakes is thin and long, and gradually tapers back from the anus, such as squirrel snakes and emerald snakes. But there are also a few non-toxic snakes with thick and short tails, such as fishing snakes.
4. Distinguish from the ecology of snakes. After discovering people, poisonous snakes generally don't escape, or they don't climb fast when they escape; When resting or sleeping, the head is mostly inserted under the ventral skin (except Agkistrodon halys). After being disturbed, they get up and climb quickly, such as Zaocys and Golden Snakes.
5. Distinguish from the feeling of touching a snake. When grasping with your bare hands, you will feel soft immediately when you meet poisonous snakes, such as cobras and silver ring snakes. When it comes into contact with non-poisonous snakes, it immediately feels tough, such as squirrel snakes and red chain snakes.
6. The most fundamental difference is that poisonous snakes have fangs and glands, but not poisonous snakes.
Misunderstanding of poisonous snakes
Misunderstanding 1
Small snakes are not poisonous.
Although Agkistrodon Viper 7 is generally bitten by a big snake, in many cases, the newly hatched snake may be more poisonous than the mother snake with a thick teacup. For example, snakes often prey and inject less venom when they bite. On the contrary, small snakes, especially newly hatched ones, prey less, so they will inject more venom when biting, and most of the newborn cubs of small snakes are not afraid of tigers and are fierce to people. Many snake owners and even snake experts have learned this lesson.
In addition, different kinds of snakes have different toxicity. For example, bungarus multicinctus is usually small, but its venom is extremely toxic. Therefore, even if you encounter a small snake, you can't take it lightly. I believe everyone has seen such a scene: several boys are chasing a small snake with big sticks and stones. You should know by now that this is not just fun. Besides, snakes themselves are extremely beneficial to human beings, and we should try our best to protect every living thing in the wild.
Misunderstanding 2
I was bitten by a snake, but I didn't feel sick for a few minutes. It must not be a poisonous snake.
Viper 8 This is an extremely common cognitive fallacy, even in many web pages? Field classroom? There is something similar to misleading children in the column. In fact, some symptoms after being bitten by poisonous snakes take 1 to 4 hours to appear. For example, the First Affiliated Hospital of Fujian 1997 admitted an 8-year-old child. He was bitten by a bungee snake for four hours, which delayed the most precious rescue time. Later, after many efforts, I was still in a coma for more than a week before I woke up. There are not a few such snake patients admitted to the hospital!
Misunderstanding 3
Bitten by a snake, my life is over.
First of all, it must be made clear that there are no poisonous snakes in the wild, and people bitten by poisonous snakes may have severe pain, redness and even fainting due to excessive mental stress. This is the result of psychological suggestion.
Even if there is a poisonous snake bite, it is mostly caused by many factors. When a poisonous snake bites, it does not necessarily release venom or inject enough venom into the human body. Only a small number of people bitten by poisonous snakes have severe poisoning symptoms, and some are life-threatening.
How to avoid poisonous snakes
1. When hiking, you should avoid inaccessible grasslands and dense forests. You can take a long soft stick or bamboo pole and beat a dozen roadside grasses while walking. Snakes will run away quickly and generally don't take the initiative to attack. In addition, put on pants and rubber shoes before entering the grass, and tie the trousers to prevent poisonous snakes from attacking.
2. In the early morning and evening after rain, it is best not to walk in the environment where poisonous snakes are active, especially in the days after the flood, and it is not suitable for entering the mountains. This is the most frequent time period for poisonous snakes to swim.
3. Observe carefully before turning stones and picking wild fruits, and beat them with bamboo poles. This is because some snakes often inhabit trees (such as bamboo leaves), and their body color is similar to the trunk. If they are not careful, they will be bitten by it.
4. Try to avoid resting in the grass. When camping, sprinkle realgar, lime powder or soaked tobacco leaves around the tent, and then zip up the tent completely. When cleaning the mat or tent in the morning, check it carefully. It is possible that that lovely snake slept with you last night.
5. Keep calm and quiet after seeing poisonous snakes. Don't move or run suddenly. You should go around or retreat slowly. Don't attack unless you are absolutely sure. Once the snake catches up with you, don't run straight or go downhill. Run out? What? Font route.
6. Snakes hate essential balm. You'd better take some when you go hiking in the wild. In addition, you should also take some snake medicine with a wide range of treatment.