Vitelline duct


Vitelline duct
Vitelline duct
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Fetus of about eight weeks, enclosed in the amnion. (Vitelline duct labeled at lower right.)
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Sketches in profile of two stages in the development of the human digestive tube. (Vitelline duct labeled on bottom image.)
Gray's subject #10 54
Days 28
Precursor midgut, yolk sac
MeSH Vitelline+Duct

In the human embryo, the vitelline duct, also known as the omphalomesenteric duct, is a long narrow tube that joins the yolk sac to the midgut lumen of the developing fetus.[1] It appears at the end of the fourth week, when the yolk sac presents the appearance of a small pear-shaped vesicle (the umbilical vesicle).

Contents

Obliteration

Generally, the duct fully obliterates (narrows and disappears) during the 7th week of fertilization age (9th week of gestational age), but a failure of the duct to close is termed a vitelline fistula. This results in discharge of meconium from the umbilicus.[2] About two per cent of fetuses exhibit a type of vitelline fistula characterized by persistence of the proximal part of the vitelline duct as a diverticulum protruding from the small intestine, Meckel's diverticulum, which is situated about two feet above the ileocecal junction and may be attached by a fibrous cord to the abdominal wall at the umbilicus.

Afterbirth

The vesicle can be seen in the afterbirth as a small, somewhat oval-shaped body, the diameter of which varies from 1 mm to 5 mm. It is situated between the amnion and the chorion and may lie on or at a varying distance from the placenta.

Sometimes a narrowing of the lumen of the ileum is seen opposite the site of attachment of the duct.

Mnemonic

A mnemonic used to recall details of a Meckel's diverticulum is as follows: "2 inches long, 2 feet from ileocecal valve, 2% of population, 2% symptomatic, 2 types of ectopic tissue: gastric and pancreatic."

Additional images

External links

References

  1. ^ Le, Tao; Bhushan, Vikas; Vasan, Neil (2010). First Aid for the USMLE Step 1: 2010 20th Anniversary Edition. USA: The McGraw-Hill Companies, Inc.. pp. 122. ISBN 978-0-07-163340-6. 
  2. ^ Le, Tao; Bhushan, Vikas; Vasan, Neil (2010). First Aid for the USMLE Step 1: 2010 20th Anniversary Edition. USA: The McGraw-Hill Companies, Inc.. pp. 122. ISBN 978-0-07-163340-6. 

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Look at other dictionaries:

  • vitelline duct — n OMPHALOMESENTERIC DUCT * * * vitellointestinal duct yolk stalk …   Medical dictionary

  • vitelline duct — (PLATYHELMINTHES: Turbellaria) One of paired ducts connecting the vitelline glands to the common vitelline duct …   Dictionary of invertebrate zoology

  • vitelline duct — noun : the duct by which the yolk sac or umbilical vesicle remains connected with the alimentary tract of the vertebrate embryo * * * vitelline duct, = yolk stalk. (Cf. ↑yolk stalk) …   Useful english dictionary

  • common vitelline duct — (PLATYHELMINTHES: Turbellaria) Connects the vitelline ducts to the ootype …   Dictionary of invertebrate zoology

  • Vitelline — can refer to:* Vitelline duct * Vitelline veins …   Wikipedia

  • duct — A tubular structure giving exit to the secretion of a gland or organ, capable of conducting fluid. SEE ALSO: canal. SYN: ductus [TA]. [L. duco, pp. ductus, to lead] aberrant ducts SYN: aberrant ductules, under ductule …   Medical dictionary

  • duct of Cuvier — the common cardinal vein. The anterior cardinal vein returns blood from the head and the posterior cardinal vein from the trunk, joining together as the common cardinal vein (also called incorrectly the vitelline vein). The jugular vein from the… …   Dictionary of ichthyology

  • omphalomesenteric duct — n the duct by which the yolk sac or umbilical vesicle remains connected with the alimentary tract of the vertebrate embryo called also vitelline duct, yolk stalk …   Medical dictionary

  • yolk duct — see vitelline duct …   Dictionary of invertebrate zoology

  • omphalomesenteric duct — noun : vitelline duct …   Useful english dictionary


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