An Introduction to Endocrinology

Abstract

Endocrinology is the study of hormones. The term hormone is derived from the Greek word harmao (I excite) and was used by the legendary physiologist E. H. Starling in his Croonian lectures at the Royal College of Physicians in 1905. He proposed, with remarkable prophecy, that these substances are secreted by one organ and are transported by the bloodstream (“ductless transport”) to other organs at distant sites, on which they exert their diverse effects. It was further speculated at that time, again with remarkable accuracy, that these “chemical messengers” had a rather rapid onset of action and excited their target organs even in extremely small quantities. Since then, endocrinology has evolved into an extremely sophisticated branch of internal medicine. A brief historical review of the events that have bridged the past and the present is pertinent, since it illustrates how the echoes of the past have been profoundly visionary.