12 Key and Core Catalog With a mechanical key system, the level of security is determined by masterkey control. A masterkey system enables facilities of any size to manage the building by defining access by person and by area in increasing levels of complexity. Since BEST invented the standard for masterkey systems, there is no
When they occur in the upper part of the aorta, they are called thoracic aortic aneurysms. Aneurysms can occur anywhere in the thoracic aorta, including the ascending aorta near the heart, the aortic arch in the curve of the thoracic aorta and the descending aorta in the lower part of the thoracic aorta.
Thoracic aorta: The thoracic aorta is a section of the aorta, the largest artery in the body, within the chest. Specifically, the thoracic aorta is that part of the aorta that starts after the arch of the aorta and runs down to the diaphragm, the great muscle that separates the chest from the abdomen.