ABSTRACT
Study objectives Compare the functions of the right side of the heart and the left side of the heart Compare the functions of the arterial system and the venous system Describe the functions of the three major mechanical components of the heart: atria, ventricles, and valves Describe the route of blood ow through the heart Discuss the functions of the chordae tendinae and the papillary muscles Explain why the thickness of the myocardium varies between the different heart chambers Compare and contrast the functional and structural features of cardiac muscle and skeletal muscle Discuss the sources of calcium for myocardial contraction Explain the mechanism of action of cardiac glycosides in congestive heart failure Understand the physiological importance of the myocardial syncytium Describe the components of the specialized electrical conduction system of the heart Explain how the pacemaker of the heart initiates the heartbeat Understand the physiological importance of the atrioventricular (AV) nodal delay Describe the mechanism and the physiological signicance of the rapid electrical conduction through the Purkinje bers Compare and contrast the action potentials generated by the sinoatrial (SA) node and the ventricular muscle cells Distinguish between the types of sodium channels and calcium channels involved in the initiation and the conduction of the electrical impulse through the heart Discuss the mechanism and the physiological signicance of the effective refractory period List the types of information obtained from an electrocardiogram Describe each of the components of the electrocardiogram Dene tachycardia and bradycardia Understand how arrhythmias may be treated pharmacologically Dene systole and diastole Describe the mechanical events, the status of the valves, and the pressure changes that take place during each phase of the cardiac cycle
•
• •
• • •
•
• •
• •
• •
•
•
•
•
• • • • • •
. Introduction The cardiovascular system includes the heart, which serves as a pump for the blood, the blood vessels, which transport the blood throughout the body, and the blood. Under normal conditions, this system is a continuous, closed circuit, meaning that the blood is found only in the heart and the blood vessels. The heart, in particular, is discussed in this chapter and in Chapter 15. The blood vessels and the circulatory system, in general, are considered in Chapter 16. Finally, the blood and hemostasis are addressed in Chapter 17.
