The endocrine system

Abstract

The endocrine system allows for the communication between the multiple cells and organs and is comprised of complex network of hormones, hormone receptors, carrier molecules, and signaling pathways. Characteristic of this system is that hormones generally act on cells that are physically separated from the secretory cell/gland, often traveling through the circulatory system to reach target tissues. Hormonal regulation is achieved by the ability of hormones to have specific biologic activity at their target tissues, important for energy production and metabolism, somatic growth and development, reproduction, and ability for the body to respond to internal and external stimuli. These complex interactions utilize controlled mechanisms of hormone synthesis and secretion and communication with other signaling molecules. Hormone deficiency or excess can each result from glandular or extraglandular processes and can be assessed clinically by laboratory testing that may include provocative testing if indicated.