■        Aorta is formed from the termination of the Left Ventricle. It connection with the Ventricle is guarded by an Aortic Valve.

■        Aorta is further divided into the following parts :

• Ascending Aorta is the first part of aorta that arises from the left ventricle. It runs along the pulmonary artery in a twisted manner. First it is posterior then lies to the right and then comes anterior to the pulmonary artery.

• Arch of Aorta is the second curved part of the Aorta. Here it curves around the Pulmonary Arteries making a semi circle, and passes on to the posterior side.

• Thoracic Aorta is the first part of the Descending Aorta. It lies inside thorax and runs vertically downwards. It ends at Diaphragm.

• Abdominal Aorta is the second part of the Descending Aorta. It lies next to the Thoracic Aorta and start below the Diaphragm. It ends by dividing into two branches near pelvis.

COURSE AND BRANCHES

Aorta starts in a spiral fashion around the Pulmonary Artery and forms a curve around its bifurcation. Rest of the part after curve is straight and downwards. It gives of branches in each part as follows :

Ascending Aorta :

■        2 Coronary Arteries (Right and Left)

Arch of Aorta :

■        Brachiocephalic Trunk (branches into Right Subclavian and Right Common Carotid Artery)

■        Left Common Carotid Artery

■        Left Subclavian Artery

Thoracic Aorta :

■        Left Bronchial Arteries (superior,inferior)

■        Oesophageal Arteries

■        3rd to 11th Posterior Intercostal Arteries of both sides and Subcostal Arteries

Abdominal Aorta :

■        Inferior Phrenic Arteries

■        Lumbar Arteries

■        Celiac Trunk along stomach

■        Superior Mesenteric Artery

■        Inferior Mesenteric Artery

■        Middle Suprarenal Arteries

■        Renal Arteries

■        Gonadal Arteries :

○        Testicular Arteries in males

○        Ovarian Arteries in females

Branches at Termination of Aorta :

■        Right and Left Common Iliac Arteries

■        Median Sacral Artery

FUNCTION AND SIGNIFICANCE 

■        Aorta supplies whole of the body with Oxygenated blood and nutrition through its branches and constitutes Systemic Circulation.

■        Aorta is frequently associated with Aneurysms (abnormal dilation), Coarctation (narrowing), Stenosis (constriction and hardening) in conditions like Marfan Syndrome, Ehlers-Danlos Syndrome, and Atherosclerosis etc.

■        Trauma and injury to Aorta specially in thoracic region is dangerous and any rupture here is rapidly fatal.