What is the aorta? The aorta is the largest blood vessel in the body. It is a very powerful artery that originates in the heart and carries oxygen-rich blood . What is an aneurysm? An aneurysm is a bulge or balloon in the wall of a blood vessel. The majority of aortic aneurysms occur in the abdominal area, but may also occur anywhere along the blood vessels that divide after leaving the abdominal aorta. For more helpful information , just click on the link: Abdominal Aortic Aneurysm