{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}


Toxicology_notes - Biology 232 Toxicology 1 Toxicology =...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology 232 Toxicology 1 Toxicology = Study of adverse affects of substances on human health o How the body processes and reacts to poisons Toxins - derived naturally from plants and animals (e.g. ricin, strychnine, aflatoxin) Toxicants resulting from human activities (Arsenic, DDT, Hg, PCBs, etc). Toxicologists determine relative toxicity of compounds LD 50 = dose at which 50% test animals die within specified time frame Anything can be toxic – depends upon dose (Exhibit 2.1, p 52-53) Depends on frequency, intensity and duration of exposure TOXICOKINETICS = Absorption, distribution, metabolism, excretion Absorption: routes = Inhalation, ingestion, dermal contact Human envelope = boundary separating interior of body from exterior environment Dose = a quantification of exposure (mg/liter, ug/m 3 , concentration) Biologically effective dose = quantity available to interact with vulnerable tissue Distribution – toxicant distributed through body via bloodstream, lymph system via diffusion Metabolism - chemically transformed by enzymes into metabolites Cytochrome P450 - polymorphism in genes coding for P450 leads to different metabolic phenotypes Water soluble chemicals excreted more quickly Lipophilic substances stored in fat cells; Lead stored in bone Methylmercury (hydrophobic) crosses blood-brain barrier to beome neurotoxin; Inorganic mercury
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}