Cardiac anatomy from right to left

Pulmonary veins

Oxygen-rich blood enters the left atrium via the pulmonary veins.
In most cases, there are two pulmonary veins on the left and two on the right.
The middle pulmonary veins usually drain into the superior pulmonary vein.

 

Axial reconstructions showing the pulmonary veins (blue arrows) as they enter the left atrium