mesentery of small intestine UBERON:0001170 The peritoneum responsible for connecting the jejunum and ileum (parts of the small intestine) to the back wall of the abdomen. Between the two sheets of peritoneum are blood vessels, lymph vessels, and nerves. This allows these parts of the small intestine to move relatively freely within the abdominopelvic cavity. The brain, however, cannot map sensation accurately, so sensation is usually referred to the midline, an example of referred pain[WP]. EMAPA:37745 small intestinal mesentery small intestine mesentery FMA:14643 uberon MA:0001555 mesentery (proper) mesentery proper gastrointestinal system serosa gastrointestinal system mesentery peritoneal mesentery