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The interactive dog atlas · Organs · Abdomen

Jejunum and ileum jejunum et ileum

The jejunum and ileum are the long, mobile part of the small intestine: the loops in the lower part of the abdomen, held by a membrane called the mesentery.

Open in the interactive atlas Guide: Internal systems Worksheet

Educational material, not a diagnostic tool. Written by the Mantrailing România team from veterinary sources we read. Updated 14.11.2026.

Dog in left lateral view — exterior, muscles, skeleton and organs Vector study after the Ellenberger, Baum and Dittrich plates: a standing dog, head to the left, deep chest and digitigrade limbs. The four layers use the same contour: exterior with body regions, superficial muscles, skeleton and organs.
Jejunum and ileum on the atlas drawing, "Organs" layer. Left lateral view, after the Ellenberger, Baum and Dittrich plates.

Where it is

The loops of the small intestine in the ventral abdomen, held by the root of the mesentery.

Layer
Organs
System
Digestive system
Region
Abdomen

What it is and what it does

The jejunum and ileum are the long, mobile part of the small intestine, in loops held by the mesentery; the mesenteric lymph nodes lie in the mesojejunum and mesoileum. For veterinary anatomists, the ileum is only the short terminal segment, which opens into the large intestine through the ileal orifice, unlike the 40/60 division of human anatomy.

Worth remembering

In animals, the ileum is only the short segment at the end, which opens into the large intestine.

Names

  • Also called: small intestine.
  • Latin term: jejunum et ileum.
  • In Romanian: Jejunul și ileonul (Romanian page).

Guides it appears in

From the same region: Abdomen

All structures, in the atlas · Flashcards: organs