Inferior mesenteric artery

The inferior mesenteric artery (IMA) is an anterior branch of the abdominal aorta that supplies the hindgut. It is the smallest of the three anterior branches of the abdominal aorta.

Gross anatomy

  • within the mesentery of the hindgut
  • unpaired vessel from the anterior aspect of the abdominal aorta at L3 level

Initially, the IMA descends anteriorly to the aorta and then passes to the left as it continues inferiorly.

  • splenic flexure of large bowel to the upper two thirds of the rectum

The left colic and sigmoid branches of the IMA cross anterior to the ureter

Variant anatomy

  • doubled IMA
  • absent IMA
  • common trunks (e.g. left colic and rectosigmoid, rectal and colosigmoid)
  • absent left colic branch
  • Arc of Riolan (SMA/IMA connection)
Abdominal and pelvic anatomy
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Article information

rID: 12485
Section: Anatomy
Tag: cases
Synonyms or Alternate Spellings:
  • Inferior mesenteric artery (IMA)
  • IMA

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Cases and figures

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    Figure 1: inferior mesenteric artery (Gray's illustration)
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    Figure 2: branches of the abdominal aorta
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