45-57 heart (longitudinal section) 心脏 (纵剖面图)
45 atrium 心房
46-47 valves of the heart 心脏瓣膜
46 tricuspid valve (right atrioventricular valve) 三尖瓣 (右房室瓣)
47 bicuspid valve (mitral valve; left atrioventricular valve)双尖瓣（左房室瓣)
48 cusp （心脏瓣膜）瓣尖
49 aortic valve 主动脉瓣
50 pulmonary valve 肺动脉瓣
51 ventricle 心室
52 ventricular septum (interventricular septum) 心室中隔膜(室间隔)
53 superior vena cava 上腔静脉
54 aorta 主动脉
55 pulmonary artery 肺动脉
56 pulmonary vein 肺静脉
57 inferior vena cava下腔静脉