Final answer:
An aortic aneurysm occurs in the aorta, which is the largest artery in the body. It is located in the abdominal and thoracic regions.
Step-by-step explanation:
An aortic aneurysm occurs in the aorta, which is the largest artery in the body. The aorta is located in the abdominal region and can also be found in the thoracic region of the body.