The gastrointestinal tract is essentially a long tube extending from our mouth to our rectum. We rely on it to eat, break down our food and turn it into well...you get the picture.

Due to its role in breakdown and absorption of nutrients, it is important to understand the different divisions and blood supply of the gastrointestinal tract.

The abdominal section of the gastrointestinal tract develops from three embryological structures called the primordial foregut, midgut and hindgut.

And, in turn, the foregut, midgut and hindgut all derive from the three embryonic germ layers: the endoderm, mesoderm and ectoderm.

The mesoderm is what forms the peritoneum, which either completely or partially lines the organs of the peritoneal cavity including the gastrointestinal tract.

It’s important to understand these different embryological divisions as the foregut, midgut, and hindgut each have their own unique blood supply.

The foregut extends from the esophagus to the duodenum at the level of the major duodenal papilla where the pancreatic and common bile duct insert, and it consists of the esophagus, stomach, the proximal duodenum, as well as the liver, gallbladder, pancreas and spleen.

The midgut extends from the distal portion of the duodenum to the last third of the transverse colon. It consists of the distal duodenum, jejunum, ileum, cecum, appendix, ascending colon and proximal two thirds of the transverse colon.

Finally, the hindgut extends from the distal third of the transverse colon to the anal canal, above the pectinate line. It consists of the distal portion of the transverse colon, descending colon and sigmoid colon and rectum.