Уысты жылан – Мамбалар туысы

Genus of venomous snakes

Mambas are fast moving, highly venomous snakes of the genus Dendroaspis (which literally means "tree asp") in the family Elapidae. Four extant species are recognised currently; three of those four species are essentially arboreal and green in colour, whereas the black mamba, Dendroaspis polylepis, is largely terrestrial and generally brown or grey in colour. All are native to various regions in sub Saharan Africa and all are feared throughout their ranges, especially the black mamba. In Africa there are many legends and stories about mambas.

The three green species of mambas are arboreal, whereas the black mamba is largely terrestrial. All four species are active diurnal hunters, preying on birds, lizards, and small mammals. At nightfall some species, especially the terrestrial black mamba, shelter in a lair. A mamba may retain the same lair for years. Resembling a cobra, the threat display of a mamba includes rearing, opening the mouth and hissing. The black mamba's mouth is black within, which renders the threat more conspicuous. A rearing mamba has a narrower yet longer hood and tends to lean well forward, instead of standing erect as a cobra does. Stories of black mambas that chase and attack humans are common, but in fact the snakes generally avoid contact with humans. The black mamba (Dendroaspis polylepis) is a highly venomous snake species native to various parts of sub Saharan Africa. Black mambas are fast moving, nervous snakes that will strike when threatened. According to findings by Branch (2016), their venom comprises neurotoxins and cardiotoxins that can rapidly induce symptoms, including dizziness, extreme fatigue, vision problems, foaming at the mouth, paralysis, convulsions, and eventual death from respiratory or cardiac failure if untreated. Although black mamba venom is highly toxic, antivenom is available and can treat envenomation promptly. Most apparent cases of pursuit probably are examples of where witnesses have mistaken the snake's attempt to retreat to its lair when a human happens to be in the way. The black mamba usually uses its speed to escape from threats, and humans actually are their main predators, rather than prey. All mambas are classified as snakes of medical importance by the World Health Organization. efn|1=Snakes of medical importance include those with highly dangerous venom resulting in high rates of morbidity and mortality, or those that are common agents in snakebite.) Dendrotoxin 3, which inhibits acetylcholine M4 receptors. Dendrotoxin 7, commonly referred to as muscarinic toxin 7 (MT7) inhibits acetylcholine M1 receptors. with activity as a selective blocker of voltage gated potassium channels

Toxicity alone does not determine severity of envenomation; other factors include the snake's temperament, venom yields, proximity of wounds to the CNS and depth of punctures. Bites by all members of this genus are capable of causing rapid onsets of symptoms, but it is the black mamba whose bite has the worst prognosis, possibly as a result of its more terrestrial nature (having more potential for human contact), high defensiveness (having a higher possibility to deliver fatal bites instead of dry bites), large size (giving it a higher strike position proximal to the victim's brain), and higher average venom yields and potential toxicity (based on experimental results). A lethality rate of near 100% for untreated black mamba bites has been circulating between various sources, However, another snakebite survey in South Africa reported a death rate of approximately 43% among those who received ineffective treatments (15 fatal cases out of 35 patients). Since then, the number has significantly dropped with the widespread use of specific antivenom. and aspis (ασπίς), which is understood to mean "shield", but also denotes "cobra" or simply "snake", in particular "snake with hood (shield)". Via Latin aspis, it is the source of the English word "asp". In ancient texts, aspis or asp often referred to the Egyptian cobra (Naja haje), in reference to its shield like hood. The genus was first described by the German naturalist Hermann Schlegel in 1848, with Elaps jamesonii as the type species. It was misspelt as Dendraspis by Dumeril in 1856, and generally uncorrected by subsequent authors. In 1936, Dutch herpetologist Leo Brongersma pointed out that the correct spelling was Dendroaspis but added that the name was invalid as Fitzinger had coined Dendraspis in 1843 for the king cobra and hence had priority. However, in 1962 German herpetologist Robert Mertens proposed that the 1843 description of Dendraspis by Fitzinger be suppressed due to its similarity to Dendroaspis, and the confusion it would cause by its use.