Large vein (vena cava)

Large veins have extremely thin walls compared to the diameter of their lumens and, thus, often have an irregular, sometimes folded appearance, as seen in this vena cava on the left. The vena cava, the largest vein, returns blood to the right atrium of the heart; in humans, it is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown at higher magnification in the cross section on the right. Trichrome stain, 10x, 100x

As in all vessels, the tunica media contains circularly-arranged smooth muscle.

Large veins have extremely thin walls compared to the diameter of their lumens and, thus, often have an irregular, sometimes folded appearance, as seen in this vena cava on the left. The vena cava, the largest vein, returns blood to the right atrium of the heart; in humans, it is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown at higher magnification in the cross section on the right. Trichrome stain, 10x, 100x

Large veins have extremely thin walls compared to the diameter of their lumens and, thus, often have an irregular, sometimes folded appearance, as seen in this vena cava on the left. The vena cava, the largest vein, returns blood to the right atrium of the heart; in humans, it is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown at higher magnification in the cross section on the right. Trichrome stain, 10x, 100x

This image was taken of a slide from the Drexel University slide collection.