How 1o Recognize Snake Venom Poisoning 



a human. Tlie true vipers discliarge about the 

 same, perhaps slightly less. There appears to be 

 a greater variation in the amount an elapid may 

 discharge. Many victims of elapid venom poison- 

 ing have minimal signs and symj)tonis; others 

 show evidence of severe poisoning. 



The fangs of the vipers are two elongated, ca- 

 naliculated teeth of the maxillary bones. These 

 bones can be rotated so that the fangs can be 

 moved from their resting positions against the 

 upper jaw, to their biting positions, approxi- 

 mately perpendicular to the upper jaw. These 

 snakes have full control over their fangs, rais- 

 ing or lowering tliem at will as when striking, 

 biting, or yawning. The two functional fangs 

 are .shed ])eriodically and are re])l;ued by the tirst 

 reserve fangs. The fangs of the elapid snakes 

 are two enlarged anterior maxillary teeth. These 

 teeth are hollow and ai'e fixed in an erect position. 



Snake Venoms 

 The venom of most snakes is a complex mix- 



ture, chiefly proteins, many of which have enzy- 

 matic activity. Some of the effects of snake 

 venoms are due to the nonenzymatic protein por- 

 tions of the venom, while others are due to the 

 enzynu^s aiul enzymatic combinations. The symp- 

 toms and signs of snake venom poisoning may be 

 complicated by the release of several substances 

 from the victim's own ti.ssues. These autophar- 

 macologic substances sometimes render diagnosis 

 and treatment more diflicult. 



The arbitrary division of venoms into such 

 groups as neurotoxins, hemotoxins, and cardio- 

 foxhiK. while liaving some usefid pui-posc in classi- 

 fication, has led to much misundeistanding and 

 a nninbcr of errors in treatment. It has l)econie 

 inci'easingly apparent that these divisions are 

 over-simplilied and misleading. Neurotoxins can, 

 and often do. lia\e cardiofoxic or hemotoxic ac- 

 tivity, or both: cardiotoxins may have neurotoxic 

 or hemotoxic activit}', or both; and hemotoxins 

 may have the other activities. It is best to con- 

 sider (/// snake venoms capal)le of pi-oducing sev- 

 eral changes, sometimes concomitantly, in one 



Figure 1. — Figures "f fangs, venom ducts, aud venom glands of: A. Cobra lElapidaei, and B. Viper (Viperidae). 

 The fangs of elapid snakes are much shorter than those of vipers and do not rotate. In each case the venom 

 glands lie outside the main jaw muscles toward the back of the head. The venom ducts lead from the glands to 

 the bases of the hollow fangs. 



