An aneurysm is an area of a localized widening (dilation) of a blood vessel. The word "aneurysm" is borrowed from the Greek "aneurysma" meaning "a widening."
What is the thoracic and abdominal aorta?
The aorta is the large artery that exits the heart and delivers blood to the body.
It begins at the aortic valve that separates the left ventricle of the heart from the aorta and prevents blood from leaking back into the heart after a contraction, when the heart pumps blood.
The various sections of the aorta are named based upon the relation to the heart and the location in the body.
Thus, the beginning of the aorta is referred to as the ascending aorta, followed by the arch of the aorta, then the descending aorta.
The portion of the aorta that is located in the chest (thorax) is referred to as the thoracic aorta, while the abdominal aorta is located in the abdomen.
The abdominal aorta extends from the diaphragm to the mid-abdomen where it splits into the iliac arteries that supply the legs with blood.