Discovery of Secretin (First Hormone)

Discovery of Secretin (First Hormone) was made in 1902 by William Bayliss at University College London in United Kingdom. This places it within the early 20th century of medical history. This page covers the discovery's origin, its historical and scientific context, and why it remains a meaningful reference point in medical history education today.

Bayliss and Ernest Starling discovered that the intestine releases a chemical messenger, secretin, into the bloodstream to stimulate the pancreas, establishing the concept of chemical signaling between organs and leading Starling to coin the word hormone.

Landmark Theory in Context

Landmark theories reorganize how physicians and scientists understand disease and physiology at a fundamental level, often overturning consensus that had stood for decades or centuries. These theoretical breakthroughs frequently faced significant resistance from the medical establishment of their time — several of the discoveries described on this site were initially dismissed or rejected before later evidence forced their acceptance — and their influence typically extends across many downstream discoveries in drugs, devices, and clinical practice. A single landmark theory can quietly underpin dozens of later, more specific discoveries that build directly on its framework.

Why This Discovery Matters

Discovery of Secretin (First Hormone) is the kind of discovery that shows up repeatedly across medical history education — in pre-med coursework, MCAT-adjacent science content, nursing and PA programs, and general health-literacy writing — precisely because it represents a genuine before-and-after moment in how medicine understood or treated a condition. Understanding not just what was discovered but when, by whom, and under what historical circumstances turns an isolated fact into something genuinely memorable, rather than an isolated date and name to memorize without context.

Discoveries like Discovery of Secretin (First Hormone) remain part of the standard curriculum taught to medical, nursing, and pre-health students today, and are frequently referenced in popular science writing, medical dramas, and public health discussions well beyond the classroom. The fact that a discovery from 1902 still shapes practice or public understanding decades or centuries later is itself part of what makes medical history worth studying — very few fields see their foundational breakthroughs remain directly relevant for so long.

WhiteCoatRecall's discovery profiles are cross-linked to the physicians credited with them and to the games that test related facts, so a reader curious about Discovery of Secretin (First Hormone) can follow the thread from the discovery itself to the person behind it, the era it happened in, and a playable way to reinforce the facts through spaced, gamified recall rather than passive reading alone. Every discovery page links to at least three related discoveries in the same category, letting a curious reader trace how an entire field of medicine developed step by step.

Sourced from verified medical history references (NIH, Encyclopaedia Britannica, and standard medical history texts). See our medical disclaimer — this page is historical and educational content, not medical advice.