Introduction
The venom of the king cobra is highly neurotoxic to humans and if untreated, is likely to cause death in several hours from respiratory failure. (Norris, 2008) This paper will examine the neurotoxic effects of the king cobra’s venom on the central nervous system at the neuromuscular junction, the signs and symptoms of envenomation, antidote and supportive measures, and prognosis.
The Neuromuscular Junction
Movement of voluntary muscles is controlled by the central nervous system. Impulses originate in the brain, and are carried to the muscles by the neurons. Each individual neuron consists of the dendrites, the cell body, and the axon. The dendrites are branch like projections that pick up nerve impulses and convey them to the the cell body. The impulse is then sent out from the cell body through the axon to another neuron, until it reaches the neuromuscular junction. (Shier, D. et all)
The neuromuscular junction is where the axon of the neuron meets the muscle fibers. There is a small space between the axon and the muscle fibers, called the synaptic cleft, through which the nerve impulse must travel to produce a movement in the muscle. (Shier, D. et al, 2004, p.282-283) One of the ways that the impulse can be transmitted across the synaptic cleft is by the use of chemicals, called neurotransmitters. Acetylcholine is a neurotransmitter used at the neuromuscular junction of motor neurons and voluntary muscles. The end of the motor neuron axon contains small vesicles, which store acetylcholine. When a nerve impulse reaches the neuron, calcium enters the cell, and stimulates these vesicles to release the acetylcholine into the synaptic cleft. The acetylcholine travels across the cleft, and attaches to ac...
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...ility of late serum sickness.
According to Warrell, D., “snake bite (in Southeast Asia) is an occupational hazard that is very difficult to avoid completely. People should be aware of what kinds of snakes live locally, their preferred habitat, and when they are most active. Footwear and appropriate clothing should be worn when walking through the jungle or in tall grass. Houses should be checked for snakes, and should be constructed so as not to provide snakes with hiding places. Any snake should be approached with caution, whether dead or alive. (Warrell, D.)
Conclusion
Envenomation by the king cobra will quickly affect the central nervous system, inhibiting acetylcholine release and reception, causing death from respiratory failure. Venom can be neutralized by the administration of the proper antivenin, and the patient’s life can be saved.
In the beginning phases of muscle contraction, a “cocked” motor neuron in the spinal cord is activated to form a neuromuscular junction with each muscle fiber when it begins branching out to each cell. An action potential is passed down the nerve, releasing calcium, which simultaneously stimulates the release of acetylcholine onto the sarcolemma. As long as calcium and ATP are present, the contraction will continue. Acetylcholine then initiates the resting potential’s change under the motor end plate, stimulates the action potential, and passes along both directions on the surface of the muscle fiber. Sodium ions rush into the cell through the open channels to depolarize the sarcolemma. The depolarization spreads. The potassium channels open while the sodium channels close off, which repolarizes the entire cell. The action potential is dispersed throughout the cell through the transverse tubule, causing the sarcoplasmic reticulum to release
...st the sacrolemma will depolarized, thus activation potentials along the T-tubules. This signal will transmit from along the T-tubules to sarcroplasmic reticulum's terminal sacs. Next, sarcoplasmic reticulum will release the calcium into the sarcroplasm leading to the next second event called contraction. The released calcium ions will now bind to troponin. This will cause the inhibition of actin and mysoin interaction to be released. The crossbridge of myosin filaments that are attached to the actin filaments, thus causing tension to be exerted and the muscles will shorten by sliding filament mechanism. The last event is called Relaxation. After the sliding of the filament mechanism, the calcium will be slowly pumped back into the scaroplasmic reticulum. The crossbridges will detach from the filaments. The inhibition of the actin and myosin will go back to normal.
It has been shown that intrathecal administriton of GABA receptor antagonists cause hyperalgesia and allodynia. Constitutive, the increase in the endogenous GABA activity in the spinal cord alleviate pain resulting from noxious and innoxious mechanical and thermal stimuli. Different GABA receptors have different roles in alleviating thermal and mechanical pain in different animal pain models. There is no study to date that has examined the involvement of GABA A and GABA B in sensory dimension of neuropathic pain resulting from compression of spinal cord. The current study tests the hypothesis that GABA A or GABA B receptors contributes to the allodynia and hyperalgesia observed after spinal cord injury. The results showed that the effect of GABA A and GABA B receptors on mechanical hyperalgesia is similar but these receptors have different effects on thermal hyperalgesia. While using baclofen as GABA B receptor agonist does not affect the thermal pain, thermal hyperalgesia resulting from spinal cord injury was greatly alleviated by different doses of GABA A agonist, muscimol. Both Baclofen and muscimol are able to reduce the mechanical and cold allodynia has been seen after spinal cord injury but the effect of baclofen is dose dependent with no effect in higher doses used in this study. While almost all doses of muscimol were used in this study reduce the amount of cold and mechanical allodynia. The other result obtained in this study is the short term effect of GABA agonist. The anitinociceptive effect of Baclofen and muscimol appear to be maxium at 15 min after injection and gradually diminished by time and their analgesic effect disappeared 3 hours after injection.
Mongooses can kill cobras in one single bite There once was a mongoose named Rikki-Tikki-tavi. He lived in the jungles of India. One day, Rikki was washed up to a house by a big storm. The family that lived there thought that Rikki had died but decided to wrap him in a warm cloth anyway. A little while later, Rikki woke up, ate some food, and wandered off to explore the garden outside the house. There he met a tailorbird named Darzee, and a muskrat named Chuchundra. They were sad because Nag, a cobra, ate a baby bird. Just then, Nag and his wife Nagaina showed up and introduced themselves to Rikki. They knew that Rikki-Tikki-tavi would eventually save the garden and they would then be forced to leave. Both the printed copy and video show the same plot but also have some differences.
When the South American Indians eat the dead prey, they do not get poisoned because in order to get poisoned by curare, you need it to be in your blood stream. Once the curare is in your bloodstream it acts as a neuromuscular blocking agent, basically it disrupts the signals between nerve cell and muscle cells. First, curare begins to affect the muscles of the toes, ears, and eyes. After curare moves on to the muscles of the neck and limbs and finally it affects the muscles that help the lungs function, this induces
Muscle action potential is generated when the threshold value of the end plate potential is reached. Muscle fibers will contract if the potential of muscle action is great enough. The acetylcholine no longer has a chance to act on the postsynaptic membrane from the presynaptic terminal, usually within 1 millisecond of release. The enzyme acetylcholinesterase, in the location of basal lamina, hydrolyzed the remaining molecules and acetate. Since the binding of receptor sites freely reversible, hydrolysis are given the opportunity to occur either before or after acetylcholine. Sufficiently exciting muscle action potential, the fiber membrane remains contact with acetylcholine molecules in a short period of time. The presynaptic membrane transports choline back into the axom terminal after the hydrolysis of acetylcholine. The resynthesized acetylcholine is stored in presynaptic vesicles near the acetylated choline acetylated by choline acetyl transferase. Muscle action potential is initiated as the end plate potential has gone about the threshold value after a nerve action potential has been transmitted across the synaptic cleft. The muscle fiber is penetrated by an electrical current that spreads through the muscle fiber and transverse tubules (T tubules), adjacent sarcoplasmic
Not all cnidarians are known to be killers, but some cnidarians are among the most dangerous marine species known to man. Cnidarians look like delicate creatures, but the potent toxins injected into their prey can kill within minutes. The severity of a sting is determined by the species of jellyfish, the thickness of exposed skin, and the sensitivity the victim has to venom. If stung, you should not panic but find medical attention right away. You will want to wash the stung area with salt water, because freshwater will stimulate the nematocysts again. The best thing to inactivate the nematocysts is vinegar and alcohol. There are also a variety of other sources that can reduce the effect of the sting such as meat tenderizer, sugar, plant juices
The five major nerves that are related to C6 are the Axillary nerve, Radial nerve, Median nerve, Musculocutaneous nerve and the Ulnar nerve. The axillary nerve’s motor function is to supply the teres minor and deltoid muscles which are both found in the shoulder. The Radial nerve motor function it serves the triceps and extensor muscles of the forearm it sensory functions is to supply the posterior part of the arm and forearm and lateral part of the arm. The Median nerve motor function is to serve the flexor muscles and some muscles of the hand and the sensory function is to give off the palmar cutaneous branch which is on the hand. The Musculocutaneous nerve serves the fexor muscles of the arm which allows you to be able have flexibility in your arm. The ulnar nerve motor function is to supply the muscles of the hand and the
The blue-ringed octopus is one of the most venomous creatures in the ocean. You might be shocked to hear that the venom produced in their spit gland, is powerful enough to kill twenty six humans! This venom is one thousand times more powerful than cyanide! The blue-ringed octopus works by paralyzing the muscles of their prey, or whoever they feel threatened by. Most victims die of lack of oxygen, or upper respiratory attack. A victim can be saved if hooked up to life support right away.
Touch receptors are a type of mechanoreceptor because they are activated by mechanical perturbation of the cell membrane. The axon is located in either shallow or deep skin and may be encapsulated by specialized membranes that amplify pressure. When the appropriate type of pressure is applied to the skin, these membranes pinch the axon, causing it to fire. The action potential travels from the point of origin to the neuron's cell body, which is located in the dorsal root ganglion. From there, it continues through another branch of the axon into the spinal cord, even as far as the brainstem.
Botulinum toxin, also known as “Botox,” is a type of toxin injection used in modern medicine to reduce wrinkles and restore the aging face and body. There are two main types types: A and type B, which are used for treating disorders in the medical field which are available in various brands of botulinum injections including Botox, Xeomin, and Dysport. Skorin, (2004). Since 1989 the FDA approved botulinum injections for the treatment of facial wrinkles (as cited in Harvard Women’s Health p.3). Although the injections are popular for aesthetic use, however, they can also cause death or paralysis when consumed because of botulism poisoning which is produced from Clostridium botulinum bacteria. When botulinum is injected in small amounts, it prevents the body from releasing the acetylcholine that is essential for muscle contraction. It
Considered to have the world’s most dangerous land and sea animals, Australia probably wouldn’t be the most popular travel destination for most people. For me, just the thought of encountering dangerous animals gives me an adrenaline rush. Knowing there could be a chance meeting with the Eastern Brown Snake, which are known for their aggressive behavior and very bad temper and also have the second most deadliest venom in the world, intrigues me. The Gold Coast of Australia is beautiful. Miles and miles of beach and ocean gives you the chance to encounter the Box Jellyfish, the most venomous marine animal in the world. That is not just in the country, that is the entire world. That is what amazes me the most, to have a chance to see the most venomous marine animal in the entire world, in it’s natural habitat.
Following that, the patient may experience a paralysis that is prominent in the bitten limb and will then spread. Headaches and pain in the infected muscles follow, as well as mild sensory disturbances. Paralysis will ascend, causing lack of sensation in the muscles associated with swallowing and respiration, eventually leading to death.
To defend themselves from predators, animals evolved over the course of time to create more desirable and beneficial features for them. Animals still change some, but they mainly use physical defenses or other means. A common defense of animals is poison. This poison either builds in the body of the animal or they can accumulate it through nature. Creatures such as frogs secrete poison through their skin and can kill creatures as great as humans. Snakes too have poison, but they distribute it to their predators and prey through lethal or crippling bites. Also, animals make sounds that deter predators by frightening or displeasing them. Finally, they have physical defenses such as thorns and horns to fight off predators and deter them.
In acute toxicity testing animals are forced to endure repeated exposure to chemicals for up to three months. This can be to test for the effects of the chemical on organs such as the lungs, liver, heart, or nervous system. These tests cause a great deal of suffering to the animals forced to endure them due to handling, restraint, force-feeding and the horrific effects of some chemicals. Animals suffer from convulsions, seizures, paralysis and death