The root of the mesentery medially.

The root of the mesentery (or mesenteric root)-the part connected with the structures in front of the vertebral column-is narrow, about 15 cm.

The next lymph sac to appear is the unpaired retroperitoneal lymph sac at the root of the mesentery of the intestine.

The paramesenteric gutters (paramesenteric recesses, infracolic spaces) are two spaces (or recesses) in the abdominal cavity between the colon and the root of the mesentery.