pulmonary artery divides in to two ways in heart...

Blood leaving right ventricle (Rt. V) will go to the lungs through pulmonary artery (PA) undergo gaseous exchange in order to obtain oxygen and release carbon dioxide. The oxygenated blood will then flow back to the heart through pulmonary vein (PV). This cycle is called pulmonary circulation.

Refer back to your first question, unless there is leakage occured in Rt.V or PA, all blood leaving Rt. V will go to the lungs.

The blood leave the right atrium will be pumped to all part of the body through the arota. The arota will branched into a several artery. One will be pumped blood to the upper part of the body (e.g. neck, brain) and the another pump blood to the lower part of the body( e.g. leg, small intestine) and also plump blood to the lung. For the sake of hkcee, u do not need to know the name of the branching of the aorta.

2008-03-17 15:32:03 補充：
there is a spelling mistake it should be aorta not arota

According to what I know, the answer to your first question is yes.