Topography
- Ascending aorta: a short segment leaving the left ventricle in the centre of the heart base; the coronary arteries arise from the aortic bulb.
- Aortic arch (arcus aortae): curves dorsally and caudally to the left of the trachea and esophagus, and gives off the brachiocephalic trunk and the left subclavian artery.
- Descending thoracic aorta: runs in the dorsal mediastinum, ventral to the vertebral bodies and slightly left of the median plane, and gives off the dorsal intercostal arteries.
- Abdominal aorta: crosses the diaphragm through the aortic hiatus, between the crura; it gives off the coeliac, cranial mesenteric, renal, gonadal and caudal mesenteric arteries and ends at the last lumbar vertebrae by dividing into the external and internal iliac arteries and the median sacral artery.
Clinical relevance
- Patent ductus arteriosus: the fetal duct joining the aortic arch to the pulmonary trunk fails to close; continuous murmur at the left heart base.
- Subaortic stenosis: a common congenital defect in large breeds (Newfoundland, Golden Retriever, Rottweiler, Boxer).
- Persistent right aortic arch: a vascular ring that constricts the esophagus and causes regurgitation in puppies at weaning.
- Aortic thromboembolism: uncommon in dogs; causes acute paresis of the pelvic limbs.
3D model
Arch and thoracic aorta segmented from the heart CT; abdominal aorta and its branches from the abdominal CT, joined in the caudal thorax. In that CT the caudal vena cava was fused with the aorta and was separated by modelling its course; the iliac veins, lying against their arteries, remain part of this piece.