TOX 2000 Study Guide - Final Guide: Heterocyclic Compound, Spinach, Nicotine

• School: University of Guelph
• Department: Toxicology
• Course: TOX 2000
• Professor: Nigel Bunce

Document Summary

All chemicals either natural or man-made have the capacity to be toxic at high enough concentrations. Many species of plants, animals and bacteria have evolved chemicals intended to be toxic towards predators. All species have evolved mechanisms to deal with excess nutrients and unwanted toxic chemicals (cytochrome oxidases and detoxification) Steps to toxicity: exposure and absorption, delivery to target site (cell or organ, concentration at target site, toxic effects. K1 > k2 : accumulation & toxic effect. Ingestion (toxicity can be modified by enzymes, ph and microbes before absorption) Exposure of nanomaterials into gastrointestinal tract can occur after uptake of daily food, drinks and medicines. Some evidence suggests that ingested nm may pass through to lymphatics. Little research to date about ingestion exposures and the potential for distribution of nm to other tissues. Respiration (air borne toxicants can be exhaled before absorption) Inhalation of nanoparticles (or any toxicant) leads to deposition in respiratory tract and lungs.