duodenum

Etymology

From Medieval Latin duodēnum digitōrum (“space of twelve digits”) in reference to its length, from duodēnī (“twelve each”) + digitōrum, genitive plural of digitus (“finger; toe; digit”).

noun

1. (anatomy) The first part of the small intestine, starting at the lower end of the stomach and extending to the jejunum.
   The Inteſtina tenuia were burnt in many places, but not quite through any where, excepting two or three. […] The length of that which is commonly call'd the Duodenum, was about 4½ Foot. 1682, A[llan] M[ullen], An Anatomical Account of the Elephant Accidentally Burnt in Dublin, on Fryday, June 17. in the Year 1681. Sent in a Letter to Sir Will[iam] Petty, Fellow of the Royal Society. Together with a Relation of New Anatomical Observations in the Eyes of Animals: Communicated in another Letter to the Honourable R[obert] Boyle, Esq.; Fellow of the Same Society, London: Printed for Sam[uel] Smith, bookseller, at the Prince's Arms in St. Paul's Church-Yard, →OCLC, page 19
   The duodenum receives the chyme from the stomach, and has generally been believed to accomplish the second digestion, or the conversion of chyme into chyle. In the duodenum it meets with the bile, pancreatic and intestinal fluids, loses its acid properties, and becomes alkaline, probably by the agency of the soda of the bile; […] 1840, Daniel Oliver, “Nutritive Functions”, in First Lines of Physiology; Designed for the Use of Students of Medicine, 2nd edition, Philadelphia, Pa.: Published by Herman Hooker, Corner of Fifth and Chestnut Streets, →OCLC, page 251
   The duodena open into a common pouch just below the entrance of the gall-ducts. The intestine was single from the confluence of the duodena to the termination of the jejunum. 1872, B[enjamin] Thompson Lowne, Descriptive Catalogue of the Teratological Series in the Museum of the Royal College of Surgeons of England, London: Printed for the College, and Sold by R[obert] Hardwicke, 192 Piccadilly, →OCLC, series II (Abnormal Conditions Affecting the Axis in Animals), class II (Duplicity), subseries VI (In Mammals), subclass II (Homologous Union), page 27, preparation 115
   Duodenums were dissected out, fixed and photographed. 2013, “Retinaldehyde”, in Q. Ashton Acton, editor, Retinoids—Advances in Research and Application, Atlanta, Ga.: ScholarlyEditions, published 2013, page 36