the wall of aorta is larger than pulmonary artery,as aorta withstands the higher blood pressure.
2007-06-10 23:30:45 補充:
補充一下這個問題應該針對於withstand pressure多少的問題而不是關於要pump all parts of body or pump to the lung,因為pumping action的問題是牽涉到right ventricle and right ventricle.這樣的話是關於wall of ventricle的厚薄.