Anatomy - Catheter jejunostomy - general and visceral surgery
You have not purchased a license - paywall is active: to the product selection
Relevant surgical anatomy
- The jejunum is the second of three sections of the small intestine. It extends from the duodenum to the ileum.
- Its colloquial German term of “Leerdarm” or “empty bowel” stems from the fact that in most dead patients it is empty.*
- The jejunum is plicated in numerous loops and with its mesentery attaches to the posterior abdominal wall. The corresponding segment of the mesentery is called mesojejunum. When considered together with the ileum, which begins at the jejunum and terminates at the cecum, the radix mesenterii or root of the mesentery extends from the duodenojejunal flexure to the ileocecal valve.
- Since the loops of the jejunum are quite mobile, they shift their positions. While the beginning of the jejunum is well defined by the duodenojejunal flexure at the level of the second lumbar vertebra, the boundary between the jejunum and ileum is not well defined.
- Like any other hollow viscus, the jejunum is lined with a mucous membrane (tunica mucosa). On the outside the mucous membrane is enclosed by a double layer of smooth muscle (tunica muscularis), while the serosa is a reflection of the peritoneum over the exterior of the jejunum.
- The superior mesenteric artery supplying the jejunum, ileum, appendix, ascending colon and the proximal two thirds of the transverse colon courses in the proximal section of the mesenteric root.
- The jejunal arteries are branches of the superior mesenteric artery and supply the jejunum with blood. The veins of the jejunum drain into the superior mesenteric vein which parallels the superior mesenteric artery on the right and then courses posterior to the head of the pancreas to the portal vein.
- The jejunum is primarily innervated by the enteric nervous system. Peristalsis is controlled by the mesenteric plexus (Auerbach plexus), while the mucous membrane is innervated by the submucous plexus (Meissner plexus). In addition, the jejunum is also regulated by the sympathetic and parasympathetic nervous systems (in particular the vagus nerve).
ieiunus is Latin for fasting, hungry, meagre *