Chapter 1 Flashcards
What is toxicology?
It is the science that deals with the harmful effects of substances on living organisms and assessment of the probability of their occurence
What is food toxicology?
It is the study of the nature, properties, detection, and effects of toxic substances in food and their disease manifestation in humans
What did paracelus say?
All substances are poison but it is the dose that makes the poison
What is the major concept in toxicology that is based on what paracelus said known as now?
Dose response relationship
What did paracelus studies reveal?
That a substance can be harmless or beneficial in a small dose however at higher doses it could become toxic
Who is orfila(2) and what is his nationality
He is spaniah
He is a physician and the founder of toxicology
What did orfila prepare?
He prepared a systematic correlation between the biological and physical properties od poison
What did orfilla demonstrate?
He demonstrated the effects of poisons on specific organs by analyzing autopsy material for poisons and their associated tiasue damage
Whats happening in the 20th century
There is a advanced level of understanding of toxicology
How is the level of knowledge of toxic effects being revealed
Level of knowledge of the toxic effects on organs and cells is now being revealed at a molecular level
What is being recognized concerning the toxic effects?
It has been recognized that all toxic effects are caused by changes in specific cellular molecules and biochemicals
All toxins are toxicants and all toxicants are toxins
True or false
Why
False
All toxins are toxins but not all toxicants are toxins
Toxins are proteins / substances produced by living organisms / biological systems
What is a toxicant? (4)
It is a chemical substance that can injure or kill a human, animal, or plant
It can cause physical or chemical damage
The effect duration may vary
It is used often in the context of man made substances
What is a toxin? (3)
It is a specific substance produced by living organisms
It is often a protein
The effect is often immediate
What is a poison? (2)
It is a toxicant that can cause immediate adverse effect
Usually small doses are sufficient
What is a xenobiotic? (3)
It is any foreign substance to the body
It may be beneficial (pharmaceuticals) or it may be toxic (lead)
At small doses it may be non-toxic or even beneficial but as the dose increases it becomes to have a toxic or lethal effect
What is the difference between systemic toxicant vs organ toxicant? (Give an example of each)
Systemic toxicant :
It affects the whole body or many organs / tissues rather than a specific site
such as potassium cyanide that interferes with oxygen utilization by the cells thus affecting all cells and organs
Organ toxicant:
Affects tissues or organs while not producing damage to the whole body
Such as benzene: is toxic only to the blood forming tissue
And lead which is toxic to three target organs: CNS, kidneys, and hematopoitic system
What is the difference between toxicant and toxic agent?
Nothing
Toxicant is the scientific name of the toxic agent
What is a toxic agent?
It is the substitute for the scientific term: toxicant
It is anything that may cause an adverse biological effect
What are the different types of a toxic agent?
Biological ( snake venom )
Chemical ( cyanide )
Physical ( radiation )
What are the different classifications of toxins / toxicants
Cyanide Heavy metals Animal toxin Food allergy Pesticides Plant toxins Mushroom toxins Microbial toxins
What is toxicity defined as?
It is the ability of the toxicant to produce harmful effects on living organisms
What factors influence the toxicity ? (4)
Intrinsic toxicity
Dose
Response of host
Exposure conditions
