When blood is flowing through a vena cava, which main blood vessel will it flow through next? A hepatic portal vein
B hepatic vein
C pulmonary artery
D pulmonary vein

C.

Explanation:

When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the right atrium while the ventricle contracts.

As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs, where it is oxygenated.