Circular folds

Circular folds
Circular folds
	Small intestine (jejunus-ileum) with circular folds.
Details
Location	Small intestine
Identifiers
Latin	plicae circulares
TA98	A05.6.01.007
TA2	2943
FMA	15071
	Anatomical terminology [edit on Wikidata]

Thecircular folds(also known asvalves of Kerckring,valves of Kerchkring,plicae circulares,plicae circulae,andvalvulae conniventes) are largevalvularflaps projecting into thelumenof thesmall intestine.

Structure

The entiresmall intestinehas circular folds ofmucous membrane.^[1]The majority extend transversely around thecylinderof the small intestine,^[2]for about one-half or two-thirds of itscircumference.Some form completecircles.Others have a spiral direction. The latter usually extend a little more than once around the bowel, but occasionally two or three times. While the larger folds are about 1 cm in depth at their broadest part, most folds are smaller. There tends to be an alternating pattern between larger and smaller folds.^[1]

Distribution

They are not found at the commencement of theduodenum,but begin to appear about 2.5 or 5 cm beyond thepylorus.

In the lower part of the descending portion, below the point where thebileandpancreatic ductsenter the small intestine, they are very large and closely approximated.

In the horizontal and ascending portions of the duodenum and upper half of thejejunum,they are large and numerous.^[3]From this point, down to the middle of the ileum, they diminish considerably in size.

In the lower part of theileum,they almost entirely disappear; hence the comparative thinness of this portion of the intestine, as compared with the duodenum and jejunum.

Difference from other gastrointestinal folds

Unlike thegastric foldsin thestomach,they are permanent, and are not obliterated when theintestineis distended.

The spaces between circular folds are smaller than thehaustraof thecolon,and, in contrast to haustra, circular folds reach around the whole circumference of the intestine. These differences can assist in distinguishing the small intestine from the colon on anabdominal x-ray.

Function

The circular folds slow the passage of the partly digestedfoodalong the intestines, and afford an increased surface forabsorption.^[4]They are covered with small finger-like projections calledvilli(singular, villus). Each villus, in turn, is covered withmicrovilli.The microvilli absorb fats and nutrients from thechyme.

History

The circular folds are also called the valves of Kerckring,^[3]valves of Kerchkring,^[5]plicae circulares,^[3]^[4]plicae circulae,^[5]andvalvulae conniventes.^[3]

References

This article incorporates text in thepublic domainfrompage 1173of the 20th edition ofGray's Anatomy(1918)

^^a ^bRumsey, D. (2005-01-01),"SMALL INTESTINE | Structure and Function",in Caballero, Benjamin (ed.),Encyclopedia of Human Nutrition (Second Edition),Oxford: Elsevier, pp. 126–133,doi:10.1016/b0-12-226694-3/02255-9,ISBN 978-0-12-226694-2,retrieved2021-01-24
^Treuting, Piper M.; Arends, Mark J.; Dintzis, Suzanne M. (2018-01-01), Treuting, Piper M.; Dintzis, Suzanne M.; Montine, Kathleen S. (eds.),"11 - Upper Gastrointestinal Tract",Comparative Anatomy and Histology (Second Edition),San Diego: Academic Press, pp. 191–211,ISBN 978-0-12-802900-8,retrieved2021-01-24
^^a ^b ^c ^dFederle, Michael P.; Rosado-de-Christenson, Melissa L.; Raman, Siva P.; Carter, Brett W., eds. (2017-01-01),"Small Intestine",Imaging Anatomy: Chest, Abdomen, Pelvis (Second Edition),Elsevier, pp. 636–665,doi:10.1016/b978-0-323-47781-9.50031-3,ISBN 978-0-323-47781-9,retrieved2021-01-24
^^a ^bYoder, Stephanie M.; Kindel, Tammy L.; Tso, Patrick (2010-01-01), Litwack, Gerald (ed.),"Chapter Eight - Using the Lymph Fistula Rat Model to Study Incretin Secretion",Vitamins & Hormones,Incretins and Insulin Secretion,84,Academic Press: 221–249,doi:10.1016/B978-0-12-381517-0.00008-4,PMID 21094902,retrieved2021-01-24
^^a ^bBoudry, Gaëlle; Yang, Ping-Chang; Perdue, Mary H. (2004-01-01),"Small Intestine, Anatomy",in Johnson, Leonard R. (ed.),Encyclopedia of Gastroenterology,New York: Elsevier, pp. 404–409,doi:10.1016/b0-12-386860-2/00648-1,ISBN 978-0-12-386860-2,retrieved2021-01-24

External links

Anatomy photo:39:12-0302at the SUNY Downstate Medical Center - "Intestines and Pancreas: The Jejunum and the Ileum"

[:0-1] Rumsey, D. (2005-01-01),"SMALL INTESTINE | Structure and Function",in Caballero, Benjamin (ed.),Encyclopedia of Human Nutrition (Second Edition),Oxford: Elsevier, pp. 126–133,doi:10.1016/b0-12-226694-3/02255-9,ISBN 978-0-12-226694-2,retrieved2021-01-24

[2] Treuting, Piper M.; Arends, Mark J.; Dintzis, Suzanne M. (2018-01-01), Treuting, Piper M.; Dintzis, Suzanne M.; Montine, Kathleen S. (eds.),"11 - Upper Gastrointestinal Tract",Comparative Anatomy and Histology (Second Edition),San Diego: Academic Press, pp. 191–211,ISBN 978-0-12-802900-8,retrieved2021-01-24

[:2-3] Federle, Michael P.; Rosado-de-Christenson, Melissa L.; Raman, Siva P.; Carter, Brett W., eds. (2017-01-01),"Small Intestine",Imaging Anatomy: Chest, Abdomen, Pelvis (Second Edition),Elsevier, pp. 636–665,doi:10.1016/b978-0-323-47781-9.50031-3,ISBN 978-0-323-47781-9,retrieved2021-01-24

[:3-4] Yoder, Stephanie M.; Kindel, Tammy L.; Tso, Patrick (2010-01-01), Litwack, Gerald (ed.),"Chapter Eight - Using the Lymph Fistula Rat Model to Study Incretin Secretion",Vitamins & Hormones,Incretins and Insulin Secretion,84,Academic Press: 221–249,doi:10.1016/B978-0-12-381517-0.00008-4,PMID 21094902,retrieved2021-01-24

[:1-5] Boudry, Gaëlle; Yang, Ping-Chang; Perdue, Mary H. (2004-01-01),"Small Intestine, Anatomy",in Johnson, Leonard R. (ed.),Encyclopedia of Gastroenterology,New York: Elsevier, pp. 404–409,doi:10.1016/b0-12-386860-2/00648-1,ISBN 978-0-12-386860-2,retrieved2021-01-24

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