Final answer:
As a red blood cell in the posterior interventricular artery, you would travel through a series of vessels including the middle cardiac vein, coronary sinus, right atrium, and the systemic circulation via the aorta and brachial artery, before entering the radial and ulnar veins, and eventually reaching the basilic and median cubital veins in the forearm.
Step-by-step explanation:
If you were a red blood cell in the posterior interventricular artery, you would travel through an intricate network of vessels and structures to arrive in the medial portion of the forearm. Your journey would begin from the posterior interventricular artery, where you're already supplying oxygen to the heart's muscles. After oxygen exchange, you'd then enter the coronary sinus and make your way into the right atrium of the heart via the middle cardiac vein. Subsequently, you'd proceed through the right ventricle to be pumped into the pulmonary artery to receive oxygen in the lungs. After becoming oxygenated in the pulmonary veins, your path continues through the left atrium, left ventricle, and then into the systemic circulation via the aorta.
Upon exiting the aorta, you'd transition to the brachial artery and continue through the bifurcation forming the radial and ulnar arteries in the arm. Your path follows through to the deep palmar venous arches, moving to the radial vein, and then to the ulnar veins. You'd continue through to the median antebrachial vein and finally reach the more medial and superficial network including the basilic vein and median cubital vein, which is commonly used for venipuncture. This intricate path showcases the body's ability to distribute nutrients and oxygen effectively to its most distal parts, including the forearm.