The descending aorta is a major blood vessel that carries oxygen-rich blood from the heart to the lower parts of the body. It is a continuation of the aortic arch, which branches off from the heart's left ventricle. The descending aorta travels down through the chest and into the abdomen, where it eventually splits into the common iliac arteries. This vessel is divided into two sections: the thoracic aorta, which runs through the chest, and the abdominal aorta, which extends into the abdomen. The descending aorta supplies blood to vital organs and tissues, including the lungs, esophagus, and spinal cord.