Chapter 17.12, Problem 39LO

Summary Introduction

To describe: The way in which endocrine activity changes as people age.

Concept introduction: The endocrine system is the chemical signaling system that uses blood vessels as information channels. The endocrine glands are ductless organs located within the organ systems and contain groups of endocrine cells that secrete their hormones directly into their surroundings. Hormones are the chemical messengers that are secreted by the endocrine system. The hormone receptors may be found in the plasma membrane or in the intracellular compartment of the target cell.