Describe the path that the drug will enter, injected into a vein on the left arm, if it should affect the brain?

1) Through the veins of a large circle of blood circulation, the medicine will enter the right atrium, and then into the right ventricle.
2) From the right ventricle in a small circle (pulmonary arteries and pulmonary veins) will enter the left atrium.
3) Then, from the left atrium to the left ventricle, further along the aorta and carotid artery, a large circle will enter the brain.