Secretin

At the time that secretin was discovered, post-Industrial Revolution, scientific materialists were encouraging the idea of a living body being just another machine that could be explained by physics. Brothers-in-law Sir William Maddock Bayliss (1860-1924) from Staffordshire and Londoner Ernest Henry Starling (1866-1927) were the medical researchers who, in 1902, made a breakthrough which conversely hinted that there is much more unfathomable ingenuity to it than that.

They set up a gruesome experiment at University College London whereby they observed and deduced that eating food stimulates the upper gastrointestinal tract to emit what they called secretin, a chemical messenger composed of strings of amino acids, into the bloodstream, which then travels only to the pancreas (and nowhere else), where it in turn stimulates the production of digestive juices, then disappears.

Bayliss and Starling published their findings under the heading ‘The Mechanism of Pancreatic Secretion’  (1902), thereby founding the study of hormones, of which secretin was the first to be identified, although it took until the 1960s for it to be isolated. In 1905 they coined the word ‘hormone’ from the Greek word meaning ‘that which sets in motion’ and shed light on how the blood and lymph are part of the body’s communication channels.

(Images: Internet Archive Book Images at Flickr.com / Public domain, Bayliss & Starling [cropped from family group] by Wellcome Images at Wikimedia Commons / CC BY 4.0)