
Large vein
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

Lumen
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

Tunica intima
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

- Internal elastic lamina
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

Tunica media
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

- Smooth muscle (cross section)
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

Tunica adventitia
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x

Smooth muscle (longitudinal section)
This longitudinal section of a large vein was stained for elastic fibers (black). The wall of a large vein is variable depending on its location. Here, in the vena cava, longitudinally oriented smooth muscle is present in tunica intima and adventitia. In this orientation, the circularly arranged smooth muscle in the tunica media is seen in cross section. An internal elastic lamina is present. 100x