Toxicology and Toxinology Flashcards
What is a poison?
Any substance capable of producing an undesirable response in a biological system seriously affecting function or causing death
What is a toxin?
A naturally produced poison
What is a toxicant?
Produced by humans or a by product of human activities
Toxicity
Amount of toxin under defined conditions that will result in biological damge
Half life
amount of time required for half the poison to be eliminated from the body
Physiological half life
amount of time required for half the poison to be removed from the body
Part per million (ppm)
amount of toxicant in another substance
LD50
dose that is lethal for 50% of the population
Evenomation is
process of venom being injected into the body by a snake, arachnid, insect, marine life or other nasty creepy crawly
Clinical syndromes of snake bites
coagulophathy, neurotoxicity, myotoxicity, renal impairment, local reactions
Severe evonomation can lead to:
dizziness, difficulty breathing, loss of consciousness, hypotension
Signs and Symptoms of snake bites
1 or 2 small puncture wounds approx 1 cm apart
Bleeding and venom residue at site
Pain, swelling and redness
Non-specific systemic symptoms:
nausea and vomiting, headache, abdo pain, diarrhoea, diaphoresis
Coagulopathy
Procoagulants: potent pro-thrombin activator that converts prothrombin to thrombin which leads to massive fibrinogen degradation
Presynaptic Toxins
depletion of pre-synaptic vesicles and prevention of vesicle recycling leads to flaccid muscle paralysis and catecholamine release
competitively blocks postsynaptic ACh receptors leading to flaccid paralysis
Myotoxicity
Affects muscles with local or generalised tenderness and weakness which may lead to rhabdo
Signs and symptoms of redback spider bite
local symptoms: sharp transient pain, increased pain at site radiating to local lymph nodes, local sweating
systemic effects: tachycardia, nausea and vomiting, dizziness and fainting, muscle weakness and spasms, remote pain
Treatment of redback spider bite
DO NOT PRESSURE IMMOBILISE
Sydney Funnel Web Spider bite
gross muscle twitching, catecholamine release, glandular hypersecretion due to development of uncontrollable spontaneous APs in skeletal and autonomic muscle, tachycardia and hypertension, anxiety
Treatment of funnel web bite
pressure immobilisation
blue Ringed Octopus
Blockade of nerve conduction cause by Textrodotoxin which prevents AP propogation by Na channel blockage leading to paralysis
Treat with pressure immobilisation
