2010 Elsevier Ltd. All rights reserved. Cells receive information from the external environment primarily through the interaction with cell surface receptors. The interaction of soluble ligands with the extracellular domain of transmembrane receptors initiates a signal transduction cascade that allows for transmission of the signal from the outside of the cell into the cell, and thus regulates cell behavior. In this chapter, four major cell surface receptor types and their cellular signaling pathways will be discussed. Implications of the relationship between these pathways and potential for interaction with toxicants and associated pathologies are discussed.
