Arterial arcades
Loop of small intestine showing distribution of intestinal arteries
Anatomical terminology [edit on Wikidata]

The arterial arcades (intermesenteric arterial anastomoses or Riolan arcades^[1]) are a series of anastomosing arterial arches between the arterial branches of the jejunum and ileum.

Nearest the duodenum the mesenteric loops are primary, the vasa recta are long and regular in distribution, and the translucent spaces (lunettes) are extensive.

Toward the ileocolic junction, secondary and tertiary loops are observed, the vessels are smaller and become obscured by numerous fat-tabs.

The diagrams below show the arrangement and variations of the loops of the mesenteric vessels for various segments of the small intestine of average length:

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  Arterial arcades
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  Arterial arcades
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  Loop of small intestine showing distribution of intestinal arteries
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  Loop of small intestine showing distribution of intestinal arteries
• 
  Loop of small intestine showing distribution of intestinal arteries
• 
  Loop of small intestine showing distribution of intestinal arteries
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  Loop of small intestine showing distribution of intestinal arteries
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  Loop of small intestine showing distribution of intestinal arteries

• Intestinal arteries

This article incorporates text in the public domain from page 1175 of the 20th edition of Gray's Anatomy (1918)

• Anatomy photo:39:04-0102 at the SUNY Downstate Medical Center - "Intestines and Pancreas: Branches of Superior Mesenteric Artery"
• Anatomy image:7916 at the SUNY Downstate Medical Center