Snake Venom Types & Effects

Venom is a combination of specific proteins and enzymes. There are 20 enzymes that are toxic to human beings, making the venom from some snakes very dangerous. Many venomous snakes carry five or six of these toxic enzymes, not all 20. The enzyme cholinesterase, toxic to human beings, damages the central nervous system. Polypeptides are toxins that also damage the nervous system, causing respiratory and heart failure.

  1. Neurotoxic Snakes

    • Snakes in the Elapidae family carry neurotoxic venom. These snakes are found in tropical and subtropical areas. Among the snakes carrying this venom are the Mayan coral and the cape cobra. One of the most feared is the Black Mamba. This snake is in parts of eastern and southern Africa. The Black Mamba typically has an approximate length of 8 feet but has been documented to grow to 14 feet. The Black Mamba holds between 100 to 450 mg of venom, and the fatal dose for an average human being is 10 to 15 mg, making a bite from this snake almost always fatal.

    Neurotoxic Effects

    • Neurotoxic venom attacks the central nervous system. This venom spreads quickly, starting with a "pins and needles" sensation throughout the body. The area around the bite shows some swelling but is rarely painful. As the venom infects the body it will cause drowsiness and drooping eyelids. Abdominal pain, slurred speech and difficulty swallowing are effects of the venom destroying nerves that control bodily functions. The venom also causes tightness in the chest; this is the start of respiratory paralysis. The muscles around and within the chest are damaged, causing the victim to suffocate. Coma and death occur in one to 15 hours.

    Cytotoxic Snakes

    • Snakes carrying cytotoxic venom include spitting cobras, rattlesnakes, lance-head vipers and several adders. Specifically, the puff adder is classified in the family viperidae. This snake is responsible for 60 percent of the snake bites in Africa. Not all are fatal bites. The puff adder has the highest incidence of attacks but is not the most venomous in Africa. The puff adder's approximate length is 3 feet, with rare sightings of more than 6 feet.

    Cytotoxic Effects

    • Cytotoxic venom attacks the blood cells and tissue. The venom acts slowly, moving from the bite mark throughout the body. The first effects will be pain and immediate swelling at the puncture site. The victim will complain of nausea and begin to vomit. The venom will begin to damage capillaries and cause hemorrhagic spots from blood leaking into the surrounding tissue. Muscle twitching and an increased heart rate will occur. Depending on the overall health and age of the victim, the increased heart rate may cause a heat attack. The victim will feel weak, have shortness of breath and lose consciousness. The last stages of the venom will produce blood in the urine and, without proper treatment, death.