The Aorta: Largest Artery, Structure, and Function

The aorta is the main systemic artery, originating from the left ventricle and distributing oxygenated blood to the entire body.

Segments

• Aortic Root: Includes valve, sinuses of Valsalva, sinotubular junction.
• Ascending Aorta: ~5 cm; gives coronary arteries.
• Aortic Arch: Gives brachiocephalic trunk, left common carotid, left subclavian.
• Descending Thoracic Aorta: In chest; gives bronchial, esophageal, intercostal branches.
• Abdominal Aorta: Below diaphragm; gives celiac, SMA, renal, IMA, iliac branches.
• Common Iliac Arteries: Terminal bifurcation at L4.

Wall Structure

• Tunica intima (endothelium), media (elastic lamellae + smooth muscle), adventitia (collagen, vasa vasorum).
• Elastic artery: high elastin content buffers pulse pressure (Windkessel effect).

Clinical Importance

• Aneurysm (dilatation >1.5× normal): ascending (surgical emergency), abdominal (screening >65 male smokers).
• Dissection: intimal tear → false lumen; Stanford A (ascending) = surgery; B (descending) = medical/TEVAR.
• Coarctation: congenital narrowing near ligamentum arteriosum.
• Atherosclerosis: plaque in abdominal aorta → embolization, occlusion.

The aorta's integrity is vital for systemic perfusion.