Science, Tech, Math › Science Anatomy of the Heart: Aorta Share Flipboard Email Print Lauren Shavell / Design Pics / Getty Images Science Biology Anatomy Basics Cell Biology Genetics Organisms Physiology Botany Ecology Chemistry Physics Geology Astronomy Weather & Climate By Regina Bailey Biology Expert B.A., Biology, Emory University A.S., Nursing, Chattahoochee Technical College Regina Bailey is a board-certified registered nurse, science writer and educator. Her work has been featured in "Kaplan AP Biology" and "The Internet for Cellular and Molecular Biologists." our editorial process Regina Bailey Updated June 24, 2019 Arteries are vessels that carry blood away from the heart and the aorta is the largest artery in the body. The heart is the organ of the cardiovascular system that functions to circulate blood along with pulmonary and systemic circuits. The aorta rises from the left ventricle of the heart, forms an arch, then extends down to the abdomen where it branches off into two smaller arteries. Several arteries extend from the aorta to deliver blood to the various regions of the body. Function of the Aorta The aorta carries and distributes oxygen-rich blood to all arteries. Most major arteries branch off from the aorta, with the exception of the main pulmonary artery. Structure of the Aortic Walls The walls of the aorta consist of three layers. They are the tunica adventitia, the tunica media, and the tunica intima. These layers are composed of connective tissue, as well as elastic fibers. These fibers allow the aorta to stretch to prevent over-expansion due to the pressure that is exerted on the walls by blood flow. Branches of the Aorta Ascending Aorta: initial part of the aorta that begins from the aortic valve and extends from the left ventricle of the heart to the aortic arch.Coronary Arteries: arteries branching from the ascending aorta to supply oxygenated blood to the heart wall. The two main coronary arteries are the right and left coronary arteries.Aortic Arch: curved section at the top of the aorta that bends backward connecting the ascending and descending portions of the aorta. Several arteries branch off from this arch to supply blood to the upper regions of the body.Brachiocephalic Artery: supplies oxygenated blood to the head, neck, and arms. Arteries branching from this artery include the right common carotid artery and the right subclavian artery.Left Common Carotid Artery: branches from the aorta and extends up the left side of the neck.Left Subclavian Artery: branches from the aorta and extends to the left side of the upper chest and arms.Visceral Branches: supply blood to the lungs, pericardium, lymph nodes, and esophagus.Parietal Branches: supply blood to the chest muscles, diaphragm, and spinal cord.Descending Aorta: major portion of the aorta that extends from the aortic arch to the trunk of the body. It forms the thoracic aorta and abdominal aorta.Thoracic Aorta (Chest Region):Abdominal Aorta:Celiac Artery: branches from the abdominal aorta into the left gastric, hepatic, and splenic arteries.Left Gastric Artery: supplies blood to the esophagus and portions of the stomach.Hepatic Artery: supplies blood to the liver.Splenic Artery: supplies blood to the stomach, spleen, and pancreas.Superior Mesenteric Artery: branches from the abdominal aorta and supplies blood to the intestines.Inferior Mesenteric Artery: branches from the abdominal aorta and supplies blood to the colon and rectum.Renal Arteries: branch from the abdominal aorta and supply blood to the kidneys.Ovarian Arteries: supply blood to the female gonads or ovaries.Testicular Arteries: supply blood to the male gonads or testes.Common Iliac Arteries: branch from the abdominal aorta and divide into internal and external iliac arteries near the pelvis.Internal Iliac Arteries: supply blood to the organs of the pelvis (urinary bladder, prostate gland, and reproductive organs).External Iliac Arteries: extend to the femoral arteries to supply blood to the legs.Femoral Arteries: supply blood to the thighs, lower legs, and feet. Diseases of the Aorta Sometimes, the tissue of the aorta can be diseased and cause serious problems. Due to the break down of cells in diseased aortic tissue, the aortic wall weakens and the aorta can become enlarged. This type of condition is referred to as an aortic aneurysm. Aortic tissue may also tear causing blood to leak into the middle aortic wall layer. This is known as an aortic dissection. Both of these conditions may result from atherosclerosis (hardening of the arteries due to cholesterol build up), high blood pressure, connective tissue disorders, and trauma.