Wiktionary
vasa recta
n. (vas rectum English)
Wikipedia
Vasa recta (intestines)
For the kidney structure, see straight arterioles of kidney
Vasa recta are straight arteries coming off from arcades in the mesentery of the jejunum and ileum, and heading toward the intestines.
The arcades are anastomoses of the jejunal and ileal arteries, branches of superior mesenteric artery.
The vasa recta of the jejunum are long and few, compared to the ileum where they are numerous and short.