Large vein (vena cava)
Large veins have an extremely thin wall compared to the diameter of their lumens and thus often have an irregular, sometimes folded appearance, as seen in the low magnification image on the left. This vessel is the vena cava, the largest vein in the body, which returns blood directly to the right atrium of the heart. In humans, the vena cava is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown in the higher magnification cross section on the right. Trichrome stain, 10x, 100x
Tunica intima
Large veins have an extremely thin wall compared to the diameter of their lumens and thus often have an irregular, sometimes folded appearance, as seen in the low magnification image on the left. This vessel is the vena cava, the largest vein in the body, which returns blood directly to the right atrium of the heart. In humans, the vena cava is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown in the higher magnification cross section on the right. Trichrome stain, 10x, 100x
Tunica media >
As in all vessels, the tunica media contains circularly-arranged smooth muscle.
Tunica adventitia
Large veins have an extremely thin wall compared to the diameter of their lumens and thus often have an irregular, sometimes folded appearance, as seen in the low magnification image on the left. This vessel is the vena cava, the largest vein in the body, which returns blood directly to the right atrium of the heart. In humans, the vena cava is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown in the higher magnification cross section on the right. Trichrome stain, 10x, 100x
Smooth muscle in adventitia
Large veins have an extremely thin wall compared to the diameter of their lumens and thus often have an irregular, sometimes folded appearance, as seen in the low magnification image on the left. This vessel is the vena cava, the largest vein in the body, which returns blood directly to the right atrium of the heart. In humans, the vena cava is about 2 cm in diameter. Large veins, have a significant amount of longitudinally-oriented smooth muscle in the tunica adventitia, as shown in the higher magnification cross section on the right. Trichrome stain, 10x, 100x
Image source >
This image was taken of a slide from the Drexel University slide collection.