Arteries vs veins

Arteries typically have more regularly arranged, thicker walls than veins and have smaller diameter lumens. The tunica media is the predominate layer in arteries, the tunica adventitia is the predominate layer in veins. 400x

Arteries typically have more regularly arranged, thicker walls than veins and have smaller diameter lumens. The tunica media is the predominate layer in arteries, the tunica adventitia is the predominate layer in veins. 400x

As demonstrated in these medium vessels, the tunica intima of both arteries and veins is composed of a simple squamous epithelium, the endothelium. The tunica intima of arteries typically has a thicker connective tissue layer beneath the endothelium than is present in the accompanying vein.

An internal elastic lamina is characteristic of arteries, but is lacking in all but the largest veins. The lamina appears wavy or folded due to postmortem shrinkage of the vessel.

As demonstrated in these medium-sized vessels, the tunica media of smooth muscle is the predominate layer in arteries.

The tunica adventitia is a much more dominant component in the wall of veins compared with arteries.

In arteries, an external elastic lamina separates the tunica media from and the tunica adventitia. This layer is also referred to as external elastic lamellae.

The lumen of an artery appears more spherical than in veins, where it often appears more flattened. These features are not well demonstrated in these partial sections.