Dissect Anatomy

Muscle of Treitz (Suspensory Muscle of the Duodenum

So today I thought it would be cool to compare slides from different anatomy books to gain a better understanding from a 3D relational anatomy viewpoint. The focus for today is the muscle (ligament) of Treitz. Some texts will have it labeled as a muscle and others will depict it as a ligament. In this first slide, we see it depicted as a muscle, which is actual the way I saw it in a recent dissection I attended.

This first slide helps to show the reaction between the muscle of Treitz with the duodenojejunal angle and definitely shows the muscle continuing to the posterior abdominal wall. However, it isn’t until we get to the second slide, from Netter’s Anatomy, where we see that this muscle (ligament, whichever you would like to call it) is in continuity with the right crus of the diaphragm forming the esophageal foramen. You can then see how this muscle of Treitz acts as a suspensory muscle for the duodenum.

Now we come back to why is this important? Well, think about the about diaphragmatic breathing. The better quality of breathing we have, the more the diaphragm will move and serve as a pump for the viscera in the abdominal cavity. And with the direct connection to the duodenum, proper movement of the diaphragm will aid in digestion for even more reasons than we understood before.

The moral of the story is to keep calm, breathe and your muscle of Treitz will be happy :)

The sagittal plane cross-section within the A.C.E (aortic cavity of the epiploon) gives up a glimpse from anterior to posterior of the relationships between the (1) liver, (6) stomach, (2) transverse colon, (5) pancreases, and (4) duodenum.

One thing that al of those structures have in common is that they surround and make up the A.C.E. This region is also referred to as the omental bursa.

The fluidity and quality of the fascia in this region is of critical importance to the heath of all of these organs involved. If this region is not taken care of then the rest of the fascia around it will lose its own fluidity and restrict the mobility of the viscera.

The last few items of note that I would like to point out are:
- the (3) greater omentum laying atop and anteriorly to the transverse colon.
- the mesocolon wrapping around the colon. In this case we have the mesocolon transverse as it wraps around the transverse colon.
- the link between the mesocolon and the pancreas and duodenum via the pre-pancreatic supra-mesocolic fascia.
- the link between the pancreas to the posterior parietal peritoneum via the Fascia of Treitz
- the way the parietal peritoneum wraps around the liver linking the liver to the diaphragm

The Lesser Omentum

We speak often about the 4 layers of the greater omentum and the function it has in the body and now it is time to introduce and appreciate the lesser omentum.

The lesser omentum is located medial to the (4) lesser curve of the stomach and is surrounded by the stomach, (3) duodenum (specifically D1), (6) liver and (1) gallbladder. It serves as a channel for the hepatic pedicle, which consists of the portal vein, common hepatic duct, cystic duct and (5) hepatic artery to travel through. The common hepatic duct and cystic duct make up the (2) common bile duct. The hepatic artery comes of from the celiac trunk along the aorta.

The last points of note are the fiber directions of the lesser omentum. The (A) pars vasculosa and pars flacida run transversely with the pars vasculosa containing the hepatic pedicle. The pars condensa runs a bit more obliquely from the liver to the lesser curve of the stomach.