<P> In tricuspid valve regurgitation, these pulsations are very strong . </P> <Ul> <Li> <P> Diagram showing completion of development of the parietal veins . </P> </Li> <Li> <P> Front view of heart and lungs . </P> </Li> <Li> <P> Heart seen from above . </P> </Li> <Li> <P> Superior vena cava </P> </Li> <Li> <P> Transverse section of thorax, showing relations of pulmonary artery . </P> </Li> <Li> <P> The arch of the aorta and its branches . </P> </Li> <Li> <P> The brachiocephalic veins, superior vena cava, inferior vena cava, azygos vein, and their tributaries . </P> </Li> </Ul> <Li> <P> Diagram showing completion of development of the parietal veins . </P> </Li> <P> Diagram showing completion of development of the parietal veins . </P>

Where does blood come from superior vena cava