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.
Acute superior mesenteric arterial occlusion, in the absence of preexisting stenosis such as with embolism, causes a greater reduction in blood flow compared with other causes of intestinal ischemia. This is due to the lack of collateralization in the presence of relatively normal arterial vasculature.