Now in the bloodstream, you are to go to the left kidney, following the rules of the road Rules of the Road:
Rules of the Road:

1. You may never go the wrong way down a "one-way street"
2. You are not allowed to "create" new roads
3. You may choose any possible route


Trace your path from the superior mesenteric vein to the left renal artery, via the hepatic portal vein, heart and lungs. Once again, describe all major structures you pass by or through (but you don't need to indicate every "side road").