Lecture 3: Variation in Toxic Responses Flashcards
What is a toxin?
Toxin generally refers to toxic substances that are produced by biological systems such as plants, animals, fungi, or bacteria.
What is a toxicant?
Toxicant describes toxic substances that are produced by or are a by-product of anthropogenic (human-made).
Factors determining adverse effects?
- Intrinsic toxicity
- Dose
- Exposure conditions
- Response of host
What are biomarkers?
Biomarkers are chemicals, metabolites, susceptibility characteristics, or changes in the body that relate to the exposure of an organism to a chemical.
How can toxicity of a chemical be determined?
- Epidemiology
- In vivo
- In vitro
How can we determine toxicity by Epidemiology?
By observing human, animal, or plant populations exposed to a chemical.
How can we determine toxicity by In vivo?
By administering the chemical to animals or plants under controlled conditions and observing the effects
How can we determine toxicity by in vitro?
By exposing cells, subcellular fractions, or single-celled organisms to the chemical
What are Cyanotoxins?
These are (hepatoxin) are toxins that are produced by bacteria called cyanobacteria or blue algae.
What is hepatotoxicity?
Damage to the liver caused by a medicine, chemical, or herbal or dietary supplement.
What causes blood and cardiovascular toxicity?
damage to the liver caused by a medicine, chemical, or herbal or dietary supplement.
What causes dermal toxcity?
This toxicity may occur when a toxicant comes into direct contact with the skin
or the toxicant is distributed to the skin internally.
What is eye toxcity?
This toxicity is as a results of direct contact with a toxicant/toxin or internal
distribution to the eye.
What is immunotoxicity?
Immunotoxicity is toxicity of the immune system which takes numerous forms:
* Hypersensitivity (allergy and autoimmunity)
* Immunodeficiency
* Uncontrolled proliferation
How does nephrotoxicity occur?
The Kidneys is susceptible to toxicants as a result of its high volume of
blood flows through the organ thus filtering large amounts of toxins which
can concentrate inside our kidney tubules.
What is nephrotoxicity ?
The toxicity to the kidneys.
What is neurotoxicity?
Neurotoxicity involve toxicant damages to cells of the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves outside the CNS).
What are the primary types of neurotoxicity?
Neuronopathies (neuron injury)
* Axonopathies (axon injury)
* Demyelination (loss of axon insulation)
* Interference with neurotransmission
What is reproductive toxicity?
This toxicity involves toxicant damage to either the male or female reproductive system.
What is Respiratory Toxicity?
This toxicity relates to effects on the upper respiratory system (nose, pharynx, larynx, and trachea) and the lower respiratory system (bronchi, bronchioles, and lung alveoli)
What is selective toxicity?
A drug is harmful to a pathogen without being harmful to the host.
What is therapuetic index?
The ratio of the dose required to produce a toxic effect and the dose needed to elicit the desired therapeutic response.
What is a disadvantage of selective toxicity?
Because of biodiversity, it is not always possible to predict the toxic effect on humans and laboratory animals.
What is mechanism of action?
A term used to describe how a drug or other substance produces an effect in the body.