The capillaries are so much smaller than the vena cavas and aorta because these large blood transportation systems are under a lot of pressure. For example, when blood is first emerging from the heart it is being pumped out with extreme amounts of pressure, if the aorta was as small as the capillaries, then it would burst under the pressure causing mass amounts of internal bleeding. On the flipside, the capillaries are farther away from the heart, here the pressure is not nearly as great as it is nearer to the heart, therefore the capillaries do not need to be big, they just need to be large enough to transport nutrients from the blood to the organs.
The abdominal aorta (and inferior vena cava for that matter) is a primary retroperitoneal structure.
The organ that transports blood to the heart is the vena cava, which includes two main veins: the superior vena cava and the inferior vena cava. The superior vena cava carries deoxygenated blood from the upper body, while the inferior vena cava transports blood from the lower body. Both veins deliver this blood to the right atrium of the heart for reoxygenation.
Superior vena cava and the inferior vena cava
The superior vena cava and the inferior vena cava are directly connected to the right atrium.
vena cava
superior vena cava
Vena cava. Whereas the aorta is the body's largest artery, the vena cava is the biggest vein.
The posterior vena cava and the aorta work together to move blood to and from the lower half of the body.
The vena cavae, which returns blood from the bottom half of your body back to your heart.
An inferior vena cava diameter > 12 mm
The superior vena cava, inferior vena cava aorta and other major blood vessles
That is correct, the Vena Cava is the "mothership" of your body's vein system, and the main artery is the Aorta. The Vena Cava and the Aorta stem directly from the heart and branch into the various paths of blood vessels.
The inferior vena cava
The aorta has thicker walls as it is an artery not vein.
Inferior Vena Cava, Superior Vena Cava, Pulmonary Artery and Vein, Aorta
aorta carries oxygenated blood away from the heart to the whole body while vena cava carries de-oxygenated blood from the body to the heart
Aorta Pulmonary Arteries Pulminary Veins Superior Vena Cava Inferior Vena Cava