Chapter 20, part 2Heart chambers and valvesFigure 20.7 Structural Differences between the Left and Right VentriclesFigure 20.8 Valves of the HeartSlide 5Connective TissuesBlood Supply to the HeartFigure 20.9 Coronary CirculationSlide 9SECTION 20-3 The HeartbeatCardiac PhysiologyFigure 20.11 An Overview of Cardiac PhysiologyThe Conducting SystemFigure 20.12 The Conducting System of the HeartImpulse Conduction through the heartFigure 20.13 Impulse Conduction through the HeartThe electrocardiogram (ECG)Figure 20.14 An ElectrocardiogramSlide 19Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & PhysiologySIXTH EDITIONFrederic H. MartiniPowerPoint® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, HawaiiChapter 20, part 2The HeartCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Structural Differences in heart chambers•The left side of the heart is more muscular than the right side•Functions of valves•AV valves prevent backflow of blood from the ventricles to the atria•Semilunar valves prevent backflow into the ventricles from the pulmonary trunk and aortaHeart chambers and valvesCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.7 Structural Differences between the Left and Right VentriclesFigure 20.7a-cCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.8 Valves of the HeartFigure 20.8aCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.8 Valves of the HeartFigure 20.8bCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Connective tissue fibers of the heart•Provide physical support and elasticity•Distribute the force of contraction•Prevent overexpansion•The fibrous skeleton •Stabilizes the heart valves•Physically isolates atrial from ventricular cellsConnective TissuesCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Arteries include the right and left coronary arteries, marginal arteries, anterior and posterior interventricular arteries, and the circumflex artery•Veins include the great cardiac vein, anterior and posterior cardiac veins, the middle cardiac vein, and the small cardiac veinBlood Supply to the HeartCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.9 Coronary CirculationFigure 20.9a, bCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.9 Coronary CirculationFigure 20.9c, dCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsSECTION 20-3 The HeartbeatCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•Two classes of cardiac muscle cells•Specialized muscle cells of the conducting system•Contractile cells Cardiac PhysiologyCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.11 An Overview of Cardiac PhysiologyFigure 20.11Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•The conducting system includes:•Sinoatrial (SA) node•Atrioventricular (AV) node•Conducting cells •Atrial conducting cells are found in internodal pathways•Ventricular conducting cells consist of the AV bundle, bundle branches, and Purkinje fibersThe Conducting SystemAnimation: Heart flythroughPLAYCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.12 The Conducting System of the HeartFigure 20.12Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•SA node begins the action potential•Stimulus spreads to the AV node•Impulse is delayed at AV node •Impulse then travels through ventricular conducting cells•Then distributed by Purkinje fibers Impulse Conduction through the heartCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.13 Impulse Conduction through the HeartFigure 20.13Animation: Cardiac ActivityPLAYCopyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings•A recording of the electrical events occurring during the cardiac cycle•The P wave accompanies the depolarization of the ventricles•The QRS complex appears as the ventricles depolarize•The T wave indicates ventricular repolarizationThe electrocardiogram (ECG)Copyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.14 An ElectrocardiogramFigure 20.14aCopyright © 2004 Pearson Education, Inc., publishing as Benjamin CummingsFigure 20.14 An ElectrocardiogramFigure