SNAKE VENOM

Introduction

There are over 3,000 species of snakes, but only 15% are considered to be dangerous

Snakes are found on every continent except Antarctica

Each year there are 45,000 incidents of snake bites in the U.S. 7,000 - 8,000 are from venomous snakes On average 8 people die each year

Dangerous?Environmental Hazard Frequency Fatalities per year

Drowning N/A 6,500

Burns / Smoke Inhalation 2.2 million 5,000

Heat Exhaustion / Heat Stroke

N/A 175-200

Lightning N/A 75-300

Bee, Wasp Stings 1 million 30-120

Dog Bites / Attacks 1-3 million 10-20

Snake Envenomation 7,000 5.5

Spider Envenomation N/A 4

Scorpion Envenomation 14,000 0.33

Lifetime odds of dying from snake bite 1 in 479,992

Venom

There are 4 types of venom Hemotoxin, Mytotoxin, Neurotoxin, or Cytotoxin

Excreted through a modified parotid salivary gland Located on each side of the skull Behind the eye

Made up of a combination of proteins and enzymes

Various compounds have synergistic effects

Anatomy of a Snake Bite

Enzymes in Venom

Proteolytic Enzymes

Arginine ester hyrdolases

Collagenase Phospholipases A

and B Phosphodiesterase

s Acetylcholinestera

se

DNase and RNase NAD Nucleotidase L-Amino acid

oxidase Procoagulants Anticoagulants Hyaluronidases:

Immediate Symtoms of Cytoxin/Mytotoxin

Intense local pain Gradual swelling Nausea and vomiting Distinct metallic taste Loss of conciousness may occur Shock.

Types of cytotoxic/mytotoxic snakes Rattlesnakes (Crotalus).

Types of cytotoxic/mytotoxic snakes Lance-headed vipers (Bothrops).

Types of cytotoxic/mytotoxic snakes Puff adder (Bitis arietans)

Hemotoxic Symptoms

Severe headache and thirst Tissue swelling around the site of the

bite caused by hemorrhaging Extreme pain Destruction of red blood cells

causing a lack of oxygen in the body Internal bleeding from major organs Severe headache and thirst Death

Hemotoxic Snakes Trimeresurus wagleri- Temple Viper Bothrops Atrox Cerastes Vipera –Sand Viper Dispholidus Typus- Boomslang

Local Favorite Northern Copperhead

Hemotoxic but not particularly deadly

Neurotoxic Venom

Neurotoxic venom is fast acting and is rapidly absorbed, attacking the central nervous system.

Paralysis Respiratory Failure Death

Neurotoxic snakes Bitis Gabonica- Gabon Viper Denisonia Superba- Australian

Copperhead Ophiophagus hannah- King Cobra Dendroaspis polylepis- Black Mamba Micrurus tener tener - Texas Coral

Snake

Reaction of Phospholipase A

Enzyme splits cell membrane Helps to subdue and digest prey Highly Neurotoxic

Snakes with Phospholipase A

Why don’t snakes poison themselves? In the case of hemotoxic, mytotoxic

and cytotoxic venoms Serum in their blood which inhibits the

venom Humans use these serums as anti-

venoms

Neurotoxic snakes lack the appropriate neuro-receptors

Treatment of Snake Bites

Hospitals use anti-venoms Helps to know species of snake DO NOT attempt to suck out poison

References

http://www.popsci.com/scitech/gallery/2008-03/how-snake-venom-works

http://zoltantakacs.com/zt/sc/naja.shtml#1 http://www.medicinenet.com/snake_bites/article.htm#tocc

http://www.buzzle.com/articles/types-of-snake-venom.html

http://firstaid.webmd.com/tc/snake-and-lizard-bites-topic-overview

http://animals.howstuffworks.com/snakes/venomous-snake.htm

http://www.esf.edu/pubprog/brochure/snakes/snakes.htm

http://www.herpsofarkansas.com/Herp/SnakeBite

http://web.virginia.edu/Heidi/chapter34/Images/8883n34_11.jpg

http://www.tigerhomes.org/animal/american-copperhead.cfm

http://www.nsc.org/news_resources/injury_and_death_statistics/Documents/Odds%20of%20Dying.pdf

http://static.howstuffworks.com/gif/snake-venom.gif