The tunica intima is very similar in all blood vessels (excepting capillaries) - it is generally a single layer of epithelium with basement membrane and fibroelastic fibers
The aorta has significantly thicker walls than the superior and inferior venae cavae as the aorta is an artery that must respond to significant intraluminal pressures whereas the venae cavae are...
Inferior vena cava is a vein carrying and returning the blood to the heart, and abdominal aorta is an artery taking oxygenated blood from the heart to the various organs and tissues