Venom and Toxins

Question 1

Which snake is the most toxic, and which is the most lethal? Is there a difference between them? Why?

Answer 1

Most toxic: Inland taipan, has the smallest LD50

Most lethal: Black Mamba. Has a combined force of its small LD50, high venom yield and agressiveness.

Question 2

Why is the first symptom of a snake bite blurred vision?

Answer 2

Because the intraocular muscles of the eye become flaccid.

Question 3

Death from snake bites most commonly occurs from?

Answer 3

Respiratory paralysis

Question 4

Why do snake procoagulants result in bleeding? What can this lead to?

Answer 4

They deplete fibrinogen/fibrin, causing a loss of clotting factors, making the patient unable to clot.

Can lead to intracranial bleeding.

Question 5

Strong coagulopathy is found in which snake?

Answer 5

Brown snake

Question 6

Myotoxicity in snakebites is due to what? What might be noticed in a patient with myotoxicity?

Answer 6

It is due to myotoxic PLA2 enzymes.

Causes myoglobinuria.

Question 7

Elapids commonly have what kind of neurotoxin?

Answer 7

Postsynaptic

Question 8

What is the name of the technique employed in the first-aid treatment of snake bites?

Answer 8

The sutherland pressure immobilisation technique.

Question 9

What is the main group of snakes in Australia?

Answer 9

Elapidae

Question 10

How are antivenoms produced?

Answer 10

From hyperimmunised horses that produce IgG.

Question 11

presynaptic neurotoxins are also called?

Answer 11

Beta-neurotoxins, SPANs, or Snake sPLA2 neurotoxins.

Question 12

Which types of snake neurotoxins have a poor response to antivenom therapy?

Answer 12

Presynaptic neurotoxins.

Question 13

Strong post-neurotoxicity is found in which snake?

Answer 13

Death Adder

Question 14

Which venemous/toxic animal is responsible for the most deaths?

Answer 14

Snakes

Question 15

True or false, animals use venom for defence or offence.

Answer 15

False. They can use it for both in some cases, e.g. scorpions.

Question 16

Which venemous/toxic animal is responsible for the most hospitalisations?

Answer 16

Hornets, wasps and bees.

Question 17

What is the animal with the most rapid fatal envenomation in the world?

Answer 17

The box jellyfish.

Question 18

How many bee stings have to occur for a person without an allergy to die?

Answer 18

~300

Question 19

Strong myopathy and pre-neurotoxicity is found in which snake?

Answer 19

Tiger snake

Question 20

Generalised reactions if they occur usually happen the first time the person is stung. True or false?

Answer 20

False.

It is more common that they have a mild reaction the first time.

Question 21

How long does presynaptic paralysis usually take to manifest in a patient?

Answer 21

1-2 hours.

Question 22

What are the symptoms of a funnel-web spider bite?

Answer 22

Pain, hypertension, dysponea, muscle fasiculations, salivation, lachrymation.

Question 23

Name five toxic animals relevant to Australia.

Answer 23

1. Sydney Funnel Web Spider
2. Blue Ringed Octopus
3. Inland Taipan
4. Stonefish
5. Box Jellyfish

Question 24

What are the names and alphanumeric code-names of the two primate active toxins from the Sydney Funnel Web spider?

Answer 24

Robustotoxin (Hv1A)

Versutoxin (Ar1A)

Question 25

How many snake bites occur in Australia per year and how many of those require antivenom?

Answer 25

1000-3000 bites/year 100-500 require antivenom

Question 26

What is the physiogical effect of a funnel web spider's bite?

Answer 26

It causes slowed inactivation of the voltage-gated sodium channel, leading to uncontrolled neurotransmitter release and concomitantly muscle fasiculations and ANS symptoms.

Question 27

Presynaptic neurotoxins act how?

Answer 27

By disrupting vesicle release and vesicle recycling.

Question 28

Box jellyfish have a coiled barb mechanism for deploying venom, what is it called? Also, how many are there per mm2 on the average tentacle?

Answer 28

Nematocyst. There are approximately 1500 of them per mm2.

Question 29

What percentage of elapids carry enough venom to kill?

Answer 29

25% There are 80 elapid species and 20 of them with enough venom to kill.

Question 30

Which is more potent, postsynaptic neurotoxins or presynaptic neurotoxins?

Answer 30

Presynaptic

Question 31

Post-synaptic neurotoxins are also called?

Answer 31

Alpha neurotoxins, or | Three fingered toxins

Question 32

What is the difference between venemous and poisonous animals?

Answer 32

Poisonous animals have no mechanism for delivery. Venemous animals can deliver poison via biting or stinging act.

Question 33

Which has a quicker time of onset, presynaptic or postsynaptic neurotoxins?

Answer 33

Postsynaptic

Question 34

A typical example of a PLA2 neurotoxin is?

Answer 34

Notexin or ß-Bungarotoxin

Question 35

Strong pre-neurotoxicity is found in which snake?

Answer 35

Taipan

Question 36

Strong myotoxicity is found in which snake?

Answer 36

Mulga Snake

Question 37

Snake neurotoxins usually cause rigid or flaccid paralysis?

Answer 37

Flaccid

Question 38

Which snake is the most toxic, and which is the most lethal? Is there a difference between them? Why?

Answer 38

Most toxic: Inland taipan, has the smallest LD50 Most lethal: Black Mamba. Has a combined force of its small LD50, high venom yield and agressiveness.

Question 39

Why do snake procoagulants result in bleeding? What can this lead to?

Answer 39

They deplete fibrinogen/fibrin, causing a loss of clotting factors, making the patient unable to clot. Can lead to intracranial bleeding.

Question 40

Generalised reactions if they occur usually happen the first time the person is stung. True or false?

Answer 40

False. It is more common that they have a mild reaction the first time.

Question 41

What is the physiogical effect of a funnel web spider's bite?

Answer 41

It causes slowed inactivation of the voltage-gated sodium channel, leading to uncontrolled neurotransmitter release and concomitantly muscle fasiculations and ANS symptoms.