In humans, the dorsal aorta is a large embryonic artery that develops into the descending aorta, according to LifeMap Discovery. The descending aorta is comprised of the thoracic aorta, which supplies oxygenated blood to the chest, and the abdominal aorta, which supplies blood to the abdomen and pelvic area, according to MedicineNet.
In the first weeks of human development, the embryonic dorsal aortas, which travel the length of the embryo, are bilaterally paired, according to LifeMap Discovery. The paired aortas fuse into a single dorsal aorta, which becomes the thoracic and abdominal aorta.
The cranial portions, which are those areas toward the head, of the dorsal aorta, so named because of its position at the back side of the heart, contribute to the formation of internal carotid arteries, according to the University of Illinois at Chicago's Embryological Development of the Human.
The descending aorta's function is to supply freshly oxygenated blood from the aortic arch to smaller arteries, according to Right Diagnosis. The two sections of the descending aorta, the thoracic and abdominal aortae, travel through the chest and abdominal sections, ending at the bifurcation of the aorta into the common iliac arteries. Other arteries supplied by the descending aorta include the renal artery, common hepatic artery and the superior mesenteric artery.