I believe you would use a tracer chemical and an MRI or CT scanner.
The main artery that feeds the legs would be the femoral artery.
Why would you want to do that. You would have to cut open the heart and watch the blood move from the pulmonary artery through the heart and into the right radial artery.
Femoral
Right femoral artery, right external iliac artery, right common iliac artery, abdominal aorta, thoracic aorta, descending aorta, aortic arch, ascending aorta, right coronary artery.
the pulmonary artery
An artery in the body is like the highway where veins are the main street's. In an artery there is much more volume of blood being moved at a faster speed. It carries more blood because it is bigger then a vein. If you cut a vein the volume of blood loss would be less because of the size limiting the flow. If the femoral artery was cut the blood loss would come out much faster and be much more serious. You could expel all of your blood in a matter of minutes before a life squad could get to the scene.
Probably the femoral artery which is palpable in your loin.
Because it cuts off circulation? That would be my guess. It cuts off the blood flow to the femoral artery, which is on the inside of the thigh.
For veins the longest is The great saphenous vein. For arteries width wise it would be the aorta but length it's the the superficial femoral artery.
The common path is aortic arch > brachiocephalic artery > internal carotid arteryThe internal carotid artery branches off to provide blood to different regions of the brain e.g. ophthalmic, anterior/middle/posterior cerebral
Arteries carry oxygenated blood away from the heart. Arteries probably CAN carry deoxygenated blood if a person draws blood from a vein, then injects it into an artery. That would be very stupid though.
Yes, it would be the femoral vein. If it is cut, you could die in a matter of seconds. If it is just injured, then a clot could develop. While death from the initial injury would not be immediately, a thrown blood clot could cause an immediate, life-threatening condition.