Heart-“Pump Weight man:250-270g, woman:240-260g Thick left ventricle: 0.9-1.0cm right ventricle: 0.3-0.4cm atria: 0.1-0.2cm Valves only one direction of blood stream Cardiac muscle the near-inexhaustible myocardium (不停的节律性收缩和舒张) Blood supply of the heart coronary artery, diastolic stage(舒张期)Heart - “Pump” Weight man: 250-270g, woman: 240-260g Thick left ventricle ：0.9-1.0cm right ventricle：0.3-0.4cm atria ：0.1-0.2cm Valves only one direction of blood stream Cardiac muscle the near-inexhaustible myocardium (不停的节律性收缩和舒张) Blood supply of the heart coronary artery, diastolic stage (舒张期)