Reptile venom is comprised of complex mixtures of enzymes, proteins, amines, lipids, nucleosides and metal ions. It contains proteolytic venom that degrades molecular structures at the bite site. It also contains hemotoxic venom that destroys blood cells and neurotoxic venom that injures nerve tissue.
크레스티드게코Venom is secreted from the venom gland into a duct that runs through the mouth and reaches the fangs. Many snake and lizard species traditionally considered non-venomous have venom glands and grooved, tubular fangs.
Predators
Predation is a natural process where one animal kills and eats another animal, known as its prey. Generally, predators have certain traits that help them hunt and capture their prey including sharp teeth, claws, body structure, and venom. Often, prey animals also have traits to protect themselves against predators. These include natural defenses, such as toxins and poisons.
Snakes are a common food source for many predators including birds of prey, mammals, and other reptiles. Depending on the species, some snakes are even cannibalistic and will consume other members of their own species. This includes the pythons and anacondas of the Amazon rainforest.
Venom is a varied form of saliva that contains several types of proteins which can kill or paralyze prey. Snakes use a pumping mechanism to deliver the venom from a gland in their mouth through a tube-like set of fangs that they insert into their prey. These fangs have grooves or canals that guide the venom to the bite wound.
Venom is injected through the skin of the snake and then rapidly travels through the bloodstream to reach its target and disrupts the chemical processes that regulate muscle contractions, blood flow, and breathing. It can also cause a host of other problems, such as tissue damage, swelling, and nerve irritation. Many of the proteins found in venoms can be targeted by existing drugs. Research on venoms is ongoing.
Symptoms
Snake venoms are highly complex substances with a mixture of toxic components that bind to multiple physiologic receptors. They contain polypeptides that act as neurotoxins (including the proteolytic, hemotoxic and cardiotoxic) as well as other peptidic components. The venoms are delivered by the snake’s unique fangs during a bite.
The first symptoms of a venomous snakebite are pain in the area of the bite, swelling and loss of sensation in that region. Then, as the venom is absorbed by the circulating blood, a series of events occur:
A drop in blood pressure due to bleeding at the bite site and from other sites, resulting in a weak pulse; shock with multisystem organ failure; coagulopathy leading to abnormal clotting and a dangerously low plasma protein level; intracranial haemorrhage with severe coma; and heart failure resulting in ventricular fibrillation or cardiac arrest.
Other effects of snake venom include pulmonary embolism; renal toxicity, requiring long-term haemodialysis or even kidney transplantation; and musculoskeletal damage with muscle, connective tissue and vascular necrosis resulting in loss of limb use or amputation. Spitting cobras can spray venom into the eyes, causing conjunctivitis, corneal ulceration and erosion, and blindness [72].
If you or someone you know gets bitten by a venomous snake, seek immediate medical attention at a health facility that is equipped with appropriate equipment to diagnose and treat snakebite envenoming. This includes a health centre that has access to antivenom and is staffed by people trained in the diagnosis of snakebite envenoming.
Treatment
The venom of many snakes contains several destructive substances, which can have either local or systemic effects. Local tissue destruction is due to a variety of proteolytic enzymes such as hyaluronidase, while the systemic effects are caused by neurotoxins and hemotoxins. These compounds act mainly on ion channels or G-protein coupled membrane receptors. Snake venoms also contain components that disrupt the procoagulant activity of blood, which can lead to bleeding and clotting problems.
Snake bites are often fatal if not treated quickly. The first steps in treatment involve removing the patient from striking distance of the snake, making sure that the wound is not covered with soil or debris. Applying pressure at the bite site, using a splint or a constrictive band around the ankle/foot, is important to prevent the spread of venom. Providing the patient with adequate fluids is also necessary to treat a possible shock.
The next step involves the administration of antivenom, which is available for many snake venoms and is relatively inexpensive. Early access to safe antivenom is essential for minimizing the morbidity and mortality from snakebite. Additional medical measures include establishing intravenous access, ensuring adequate hydration and monitoring vital signs.
Prevention
Snakes don’t bite unless they perceive a threat, and they usually will flee when approached. But if you try to grab or frighten them, they may bite in self-defense. If you do get bitten, stay calm and immobilize the wound to stop the spread of venom. It’s also helpful to remember what the snake looked like or even take a photo with your phone in case you need to describe it to emergency room staff.
There are many preventative steps you can take to avoid venomous snake bites, such as wearing boots and long pants when hiking and camping in areas where snakes typically reside. Also, don’t reach into spaces and holes that you can’t see or underneath objects without first checking that a snake isn’t hiding there.
If you do get bitten, treat it as a medical emergency unless you’re absolutely sure the snake is nonvenomous. Also, make sure you have a tetanus booster in your body. If you can’t get to a hospital right away, tie an elastic wrap two inches above the bite and try not to move around. If you can’t call 911, tie the wrap loose enough to slip a finger underneath it. You should also be able to remember what the snake looked like and where it bit you, which will help emergency room doctors identify the kind of venom injected into your system.