tailieunhanh - MECHANICAL PROPERTIES OF THE HEART AND ITS INTERACTION WITH THE VASCULAR SYSTEM

All governors have some sort of safety shutdown mechanism to operate automatically or manually to close the wicket gates in case of emergency. The device is usually controlled by a solenoid. In most cases, a weighted arm that is connected to the gate limit mechanism is held in place by the solenoid. If the trip is initiated, either automatically or manually, the solenoid is de- energized, dropping the weight, causing the gate limit to go to zero. A few installations have shutdown solenoids that are designed so that they must be energized to trip. Typically, there. | Cardiac Physiology Page 1 of 23 MECHANICAL PROPERTIES OF THE HEART AND ITS INTERACTION WITH THE VASCULAR SYSTEM Daniel Burkhoff MD PhD Associate Professor of Medicine Columbia University November 11 2002 Cardiac Physiology Page 2 of 23 MECHANICAL PROPERTIES OF THE HEART AND ITS INTERACTION WITH THE VASCULAR SYSTEM Daniel Burkhoff MD PhD Associate Professor of Medicine Columbia University Recommended Reading Guyton A. Textbook of Medical Physiology 10th Edition. Chapters 9 14 20. Berne Levy. Principles of Physiology. 4th Edition. Chapter 23. Katz AM. Physiology of the Heart 3rd Edition. Chapter 15. Bers DM. Cardiac excitation-contraction coupling. Nature 2002 415 198 Learning Objectives 1. To understand the basic structure of the cardiac muscle cell. 2. To understand how the strength of cardiac contraction is regulated with particular emphasis on understanding the impact of intracellular calcium and sarcomere length . the basic concepts of excitation-contraction coupling 3. To understand the basic anatomy of the heart and how whole organ ventricular properties relate to the properties of the muscle cells. 4. To understand the hemodynamic events occurring during the different phases of the cardiac cycle and to be able to explain these on the pressure-volume diagram and on curves of pressure and volume versus time. 5. To understand how the end-diastolic pressure volume relationship EDPVR and the end-systolic pressure-volume relationship ESPVR characterize ventricular diastolic and systolic properties respectively. 6. To understand the concepts of contractility preload afterload compliance. 7. To understand what Frank-Starling Curves are and how they are influenced by ventricular afterload and contractility. 8. To understand how afterload resistance can be represented on the PV diagram using the Ea concept and to understand how Ea can be used in concert with the ESPVR to predict how cardiac performance varies with contractility preload and afterload. Cardiac .