Stomach aneurysms are generally noted in older guys with significant infrarenal atherosclerotic plaque burden as well as a thinned media. Abdominal aortas vary from thoracic rising aortas by both the enhanced visibility of inflammation in the disease state and also the embryologic origin of their vascular smooth muscle mass cells. Vascular smooth muscular tissue cells of the ascending aorta stem from the ectodermal cardiac neural crest and also the mesodermal 2nd heart field while smooth muscle cells of the abdominal aorta are mesodermally derived from the somites. It has actually been demonstrated that vascular smooth muscular tissue cells from these locations react in different ways to TGF-β stimulation.