A pattern, apart from the term's use to mean template, is a discernible regularity in the world or in a manmade design. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated like a wallpaper.
The vena cava is the major vein that returns blood to the right atrium of the heart. The vena cava superior returns blood from the head, neck, upper extremities, and chest. The vena cava inferior returns blood from the lower extremities, the pelvis, and the abdomen.
Lesson Summary. Veins are an important part of our circulatory system. They are responsible for returning deoxygenated blood back to the heart after arteries carry blood out. The vena cava is the largest vein in the body.