Which of the following is not true about second heart sounds: A: It occurs at the beginning of ventricular diastole B: Auscultation is strongest and clearest at the apex of the heart C: The tone of the heart is higher and clearer than that of the first heart D: The duration is shorter than the first heart note

单选题<br/>Which<br/>of the following statements is the most consistent with the<br/>definition of heart failure? () A: Stroke volume is decreased B: The volume of venous return is greater than that of cardiac output C: Cardiac output cannot meet body’s requirement for metabolism D: Heart dysfunction results in congestion in pulmonary and systemic<br/>circulation

Which of the following is wrong about the cardiac cycle? A: the diastolic period is longer than the systolic period B: The atria and ventricles contract at the same time C: The atria and ventricles can relax at the same time D: The length of cardiac cycle is related to heart rate

In the following description of the heart wall structure, the WRONG option is A: The heart wall consists of endocardium, myocardium and epicardium. B: The surface of endocardium is covered by endothelium. C: Purkinje fibers are distributed in the subendocardial layer of the ventricle (心室). D: Myocardium consists mainly of smooth muscle fibers. E: Epicardium is serosa.

Which indicator can be mainly reflected by the level of systolic blood pressure in general? A: Cardiac stroke volume B: Heart rate C: Peripheral resistance D: Capillary pressure in the microcirculation