Which is the correct direction of blood flow?

a) right atrium --> right ventricle --> pulmonary artery

b) right atrium --> left atrium --> pulmonary artery

c) left ventricle --> pulmonary artery --> aorta

d) left ventricle --> left atrium --> aorta

2 answers

(a) is correct for the flow of deoxygenated blood flowing on its way to the lungs for oxygen input.
b) right atrium --> left atrium --> pulmonary artery