Which anatomical defect is associated with pulmonary atresia?

Pulmonary atresia is a congenital heart defect characterized by the failure of the pulmonary valve to form properly, resulting in a complete blockage of blood flow from the right ventricle to the pulmonary artery. The choice indicating "No blood passing to the pulmonary artery" accurately describes this condition, as the absence of a functional pulmonary valve prevents any blood from entering the pulmonary artery from the heart.

In cases of pulmonary atresia, to maintain blood flow to the lungs (where oxygenation of blood occurs), alternative pathways must often develop or remain open, such as through a patent ductus arteriosus (a connection between the aorta and the pulmonary artery) or through other forms of shunts. Therefore, the scenario where no blood is passing to the pulmonary artery is a direct consequence of the condition and is therefore accurate as the right answer.

The anatomical features seen in pulmonary atresia often coexist with other defects, but the most definitive aspect is the blockage preventing blood from reaching the pulmonary artery.