The left ventricle pumps blood through the aortic semilunar valve into the aorta. From the aorta, blood enters into systemic circulation throughout the body tissues until it returns to the heart via the vena cava and the cycle repeats.he left ventricle pumps blood through the aortic semilunar valve into the aorta. From the aorta, blood enters into systemic circulation throughout the body tissues until it returns to the heart via the vena cava and the cycle repeats.
The signs and symptoms of superior mesenteric artery syndrome vary but may include: 1  Feeling full quickly when eating. 2  Bloating after meals. 3  Burping (belching)  Nausea and vomiting of partially digested food or bile-like 1  liquid. Small bowel obstruction.  Weight loss.
Background. Superior mesenteric artery (SMA) syndrome is an uncommon but well recognized clinical entity characterized by compression of the third, or transverse, portion of the duodenum between the aorta and the superior mesenteric artery.This results in chronic, intermittent, or acute complete or partial duodenal obstruction.uperior mesenteric artery syndrome was first described in 1861 by Von Rokitansky, who proposed that its cause was obstruction of the third part of the duodenum as a result of arteriomesenteric compression.