Ultrastructure in Biological Systems, Volume 7: The Anterior Pituitary presents the mechanisms involved in the release of adenohypophysial hormones. This book explores the morphological approach to fundamental aspects of pituitary cell biology. Organized into eight chapters, this book begins with an overview of how the ultrastructure of cellular organelles can yield valid criteria of identification. This text then discusses the cellular and subcellular localization of anterior pituitary hormones by immunoelectron microscopy. Other chapters consider the localization of possible receptor sites for hormonal messengers on anterior pituitary cells. This book discusses as well the in vitro systems that have undergone a significant development, which is the ultrastructure and function of dispersed anterior pituitary cells. The final chapter deals with the ultrastructure of pituitary tumors, which can be divided into two categories, namely, functional and nonfunctional, according to the presence or the absence in the host of hormonal hypersecretion signs. This book is a valuable resource for biochemists, endocrinologists, histologists, and pathologists.