110 Hormones
note of the biological significance of finding a chemical substance that traveled through the
bloodstream to deliver an activation message to an organ.
In 1902 two professors and medical researches at University College of London began
a study of digestive juices. One was 40-year-old William Bayliss. His partner was his
34-year-old brother-in-law, Ernst Starling.
Medical scientists knew that the pancreas began to secrete digestive juice as soon as
the food content in the stomach first entered the small intestine. But how did the pancreas
know that it should &Vv??F?&?GV6R?V?6RBF?B???V?C???77V?VB?V?V7G&?26?v???v26??V??r6V?BF?&?Vv??W'fR6V??2?&??72?B7F&??rFV6?FVBF?FW7BF??2F?V?'???F?W?7WBF?R?W'fW2?VF??rF?F?R?7&V2?b?&?&F?'?F?r??WBF?R?7&V27F????W&f?&?VB??7VR?W??6??6RW???F????F?W?f?V?BF?BF?R????r?bF?RF?~( ?26?????FW7F??R6V7&WFVB?V?B7V'7F?6R26???27F??6?6?B&V6?VB?B?F??2f?V?B?v??6?F?W????VB6V7&WF???G&fV?VBF?&?Vv?F?R&???G7G&V?F?F?R?7&V2?B6?v??VBF?R?7&V0?F??V??F?7F?????V???RF???R?&??72?B7F&??r??7F?F?&V??VBF?BF??2v2F?Rf?'7BF?7V?V?FVB66R?b6?v??&V??r6V?B6?V?6??F?&?Vv?F?R&?G???7FVB?bV?V7G&?6?????p??W'fRf?&W'2?F?W????V?6VBF?V?"f??F??w2?F?F?RFV?v?B?Bv??FW"?bF?R66?V?F?f?0?6???V??G???&??727W7V7FVBF?B?????&R7V6?6?V?6??W76V?vW'2W??7FVB?Bv?V?B&P?f?V?B?26???2?R&VB&W?'B??F???^( ?2v?&??&??72&V??VBF?BF???R?@?F?66?fW&VB??F?W"??F??2w&?W?b6?V?6??W76V?vW'2v?V??R?6??FVBG&V??????R7F&??r6???VBF?R??R??&???W2f?"F??2w&?v??rw&?W?b6?V?6??W76V?vW'2?g&??F?Rw&VV?v?&G2?V???r( ?F?&?W6RF?7F?f?G??( ?F?RF??&B??&???RF?&RF?66?fW&VBv26?'F?6??R????3R?'??W&?6?&??6?V?7BVGv&B6?f?????r????7B3 ???&???W2?fR&VV?F?66?fW&VBF?B7VVB6?v??2F?&?Vv???W"&?G???BF?V?"???'F?6P?6??&F?&R?fW'7FFVB??gV?f7G3?&?&W'BV&??Vv?W2?F?Rv?&?N( ?2?&vW7B???vV?v?VBC?@??r??cr?"??B??2FVF????S???V'2gFW"??2FVF??66?V?F?7G2F?66?fW&VBF?B?R?BF???GF?R?bF?R??&???RF??&????????27?7FV??v?F??W@?F??2f?F???&???R???2&?G?6?V?F?( ?B'W&?F?Rf??B?RFR??B6???0?&?G?6??F??V??7F?&VB?B2fB???&RF?W???&P?&?72??6?V??F?66?fW'??b??7V???6??6v??V??fW'6?G??b6??6v?&W72???B??f???'WF????W7F??W2???VF?6??R??Wr??&??&?F????W6R???R??g&????V?F???WF&??2&VwV?F?????V??W'7V7F?fR?&?7F???&?6?vV??V&?6?W'2?#2?V?FW'6?????????fR?bW&?W7B7F&??r??Wr??&????f?&BV??fW'6?G?&W72?#B????W6?W??v?R???&???R6???V7F?????Wr??&??&?F?R&W72?#??