Ernest Starling

Ernest Henry Starling (April 17, 1866 – May 2, 1927) was a British physiologist whose discoveries fundamentally shaped modern medical science, particularly in understanding endocrinology and cardiovascular function. Born in London, Starling pursued medicine before becoming increasingly focused on experimental physiology research. In 1902, working with William Bayliss, Starling discovered secretin, establishing the first known hormone—a chemical messenger secreted by one organ to regulate function of another. This discovery revolutionized understanding of bodily regulation, demonstrating that the body used chemical as well as neural control mechanisms. Starling went on to study the heart and blood vessels extensively, formulating Starling's Law of the Heart, which explains how cardiac output adapts to changes in blood volume. His work established fundamental principles of cardiovascular physiology that remain central to medical practice. Starling also coined the term 'hormone' itself, derived from Greek meaning 'to excite.' His laboratory at University College London became a center of physiological research, attracting scientists from across the world. Though his research was interrupted by World War I (during which he served as a physician), Starling continued his contributions to physiology until his death. His foundational discoveries laid the groundwork for modern endocrinology and remain essential to medical education.