Venomous snakes - medical aspects (1950)

e venomous snakes are found in many parts of the world and the dangers from their bites are often exaggerated much accurate scientific work has been carried out in this field but it has not always removed the superstitions of popular fancy the application of modern knowledge will greatly reduce the danger of snake bites in a limited time it is impossible to consider in detail all aspects of this subject but the characteristics of the different groups of snakes and their Venoms and the principles of adequate treatment should be widely known and are dealt with in this film all venomous snakes have two or more teeth on the upper jaw specially adapted for the injection of venom for this purpose these teeth are enlarged and canalized the Venom secreting glands lie below and behind the eyes and are connected by ducts to the fangs in Striking they are compressed by muscles and the Venom is forced through the Fang all snakes belong to the suborder serpentes of the order scata the serpentes are divided into eight f amilies of which two contain all the venomous species these are the calub and viid the calub are subdivided into three groups the AER are without fangs and are not venomous the second group The apisto have fangs at the back of the maxilla these snakes are not the ous and are not usually dangerous to man the third group The proog glyer are the front Fang snakes these comprise the elpine which include the cobras Kites and members and the hydrin or sea snakes this is the skull of the Indian cobra the fangs are at the front of the maxill two or three smaller maxillary teeth are generally found behind them on the upper surface of the head there are nine large scales or Shields this is characteristic of the calub the other family the viid are divided into the viperin or the true vipers and the croal comprising the pit vipers and rattles snakes snakes of this family have large well-developed front fangs and no other maxillary teeth in biting the fangs are rotated forward or erected the head is flattened and often triangular and the upper surface is usually covered with many small scales this is the head of a Russell's Viper the crotaline have all the features of the true vipers but in addition they have a L'Oreal pit on the side of the face between the eye on the nasal opening this is a heat receptor for the detection of warm blooded prey in darkness for comparison this is the skull of a python which is nonvenomous it has many back pointing teeth on the maxillary Palatine and tedo bones but no fangs the ctland tree snake is an epist colubrid it has back fangs and the characteristic head Shield pattern it is a slender arboreal snake with a sharp snout and is not very dangerous to man the sea snakes or hydrin may be very venomous they have flattened or shaped Tails this is a snake which is found in the Indian and Pacific Oceans the Indian cobra is an elpine only cobras possess hoods the head is small the neck is not well defined and the body and tail are long when angry it raises its head to strike and expands its Hood by spreading its anterior rib some Indian Cobras have distinctive markings on the back of the hood other cobas have no Mark at all the gaboom Viper belongs to the viperin or true vipers its head is large and triangular and its neck is well marked this snake lives on small mammals and it is usually sluggish until R when it strikes rapidly like all vipers it has a short Scout body and a Stumpy tail against its natural background of grass and sand it may be difficult to detect the full richness of its color is apparent for this Viper has recently cast its skin as it moves the pattern on the side of its body gives a curious appearance of legs the bandid timber rattle snake is one of the croal or pit vipers the rattle is seen in only two gener of pit vipers croas and cyras in contrast to the elevated striking position of the Cobra vipers make their attack from a lower level snake venom is secreted as a specialized saliva whose active agents are certain protein enzymes its purpose is to immobilize the prey and to Aid in its digestion the typical action of the Venoms of the colu is neurotoxic with paralysis while that of the viid is cytolytic with hemolysis Hemorrhage and tissue destruction clotting of the blood may also be altered these differences are not always so well defined and in some species there is considerable overlapping following lurid bites paralysis May develop and if death occurs it is from respiratory paralysis after Viper bites there is extensive tissue destruction round the bite and damage to the cardiovascular system with intravascular hemolysis and Hemorrhage death may be delayed for several days a venomous snake may be recognized by the presence of fangs which may be partly hidden in folds of mucous membrane to recognize the bite of a venomous snake Fang puncture should be sought this Dental impression from an elpine made by DR n Hamilton Fairley shows the Fang punctures and marks of the small maxillary teeth the Palatine and tedo teeth marks are seen on each side of the midline ideal treatment is is the early intravenous administration of an adequate dose of the specific antiserum in practice immediate first aid measures are essential a tight tour a should be applied at once to obstruct all blood flow to and from the limb and the patient made to lie down the bitten area is then thoroughly washed to remove Venom on the surface of the skin incisions are made through the Fang marks and in Viperine bites nearby to allow some Venom to escape with the blood and serum to encourage this Escape of Venom suction is applied either by mouth or by suction cups this is maintained intermittently for some hours the experiment has shown that lethal doses of Venom can be removed in this way the T must be briefly loosened every 10 or 15 minutes in Viper bites the tour should be applied only tightly enough to restrict the venous return from the limb the tour alone may save life in the case of Viper bites but will only postpone death after lethal doses of colubrid Venom bites on Parts where a t cannot be used should immediately be excised and suction applied antiserum as soon as it is ready is injected into a vein above the T and in Vier bites also run the bite itself General measures to combat shock paralysis Hemorrhage or secondary infection may also be required to summarize the steps in the Practical treatment of snake bit a turnic is immediately applied the bitten area is washed and enzed and suction is applied as soon as antiserum is ready it is injected and any other effects of the Venom and secondary infection are treated do