1. 1 Fig. 19.1 Copyright © McGraw-Hill Education. Permission required for reproduction or display. CO 2 O2O2 Pulmonary circuit O 2 -poor, CO 2 -rich blood O 2 -rich, CO 2 -poor blood Systemic circuit CO 2 O2O2

2. 2 Fig. 19.2 Copyright © McGraw-Hill Education. Permission required for reproduction or display. (a) Sternum 3rd rib Diaphragm Posterior Pericardial cavity Lungs Thoracic vertebra Right ventricle Sternum Left ventricle Interventricular septum Superior vena cava Right lung Parietal pleura (cut) Pericardial sac (cut) Diaphragm Apex of heart Base of heart Pulmonary trunk Aorta (c) Anterior (b)

3. 3 Fig. 19.3 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Pericardial cavity Pericardial sac: Fibrous layer Serous layer Epicardium (b) Myocardium Endocardium Epicardium Pericardial sac (c)(a)

4. 4 Fig. 19.4 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Fat in interventricular sulcus Left ventricle Right ventricle Anterior interventricular artery (a) Anterior view, external anatomy Superior vena cava Inferior vena cava Interatrial septum Left atrium Left AV valve Coronary blood vessels Tendinous cords Left ventricle Endocardium Myocardium Epicardium Base of heart Right atrium Opening of coronary sinus Right AV valve Trabeculae carneae Right ventricle Papillary muscles Epicardial fat Interventricular septum Apex of heart a,b: ©The McGraw-Hill Companies, Inc. (b) Posterior view, internal anatomy

5. 5 Fig. 19.5 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Aortic arch Superior vena cava Branches of the right pulmonary artery Right pulmonary veins Right auricle Right atrium Coronary sulcus Right ventricle Inferior vena cava (a) Anterior view Apex of heart Left ventricle Anterior interventricular sulcus Left auricle Left pulmonary veins Pulmonary trunk Left pulmonary artery Ascending aorta Ligamentum arteriosum Aorta Left pulmonary artery Left pulmonary veins Left atrium Coronary sulcus Coronary sinus Fat Left ventricle Apex of heart (b) Posterior view Right ventricle Posterior interventricular sulcus Inferior vena cava Right atrium Right pulmonary veins Right pulmonary artery Superior vena cava

6. 6 Fig. 19.6 (a) (b) Copyright © McGraw-Hill Education. Permission required for reproduction or display. b: Photo and illustration by Roy Schneider, University of Toledo. Plastinated heart model for illustration courtesy of Dr. Carlos Baptista, University of Toledo

7. 7 Fig. 19.7 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Aorta Right pulmonary artery Superior vena cava Right pulmonary veins Interatrial septum Right atrium Fossa ovalis Pectinate muscles Right AV valve Tendinous cords Trabeculae carneae Right ventricle Inferior vena cava Left pulmonary artery Pulmonary trunk Left pulmonary veins Pulmonary valve Left atrium Aortic valve Left AV valve Left ventricle Papillary muscle Interventricular septum Endocardium Myocardium Epicardium

8. 8 Fig. 19.8 Copyright © McGraw-Hill Education. Permission required for reproduction or display. b: ©Photo Researchers/Biophoto Associates/Getty Images; c: ©The McGraw-Hill Companies, Inc. Right AV (tricuspid) valve Fibrous skeleton Openings to coronary arteries Aortic valve Pulmonary valve Left AV (mitral) valve (a) Tendinous cords Papillary muscle (c) (b)

9. 9 Fig. 19.9 Superior vena cava Right pulmonary veins Right atrium Right AV valve Right ventricle Inferior vena cava Blood enters right atrium from superior and inferior venae cavae. Blood in right atrium flows through right AV valve into right ventricle. Contraction of right ventricle forces pulmonary valve open. Blood flows through pulmonary valve into pulmonary trunk. Blood is distributed by right and left pulmonary arteries to the lungs, where it unloads CO 2 and loads O 2. Blood returns from lungs via pulmonary veins to left atrium. Blood in left atrium flows through left AV valve into left ventricle. Blood flows through aortic valve into ascending aorta. Blood in aorta is distributed to every organ in the body, where it unloads O 2 and loads CO 2. Blood returns to right atrium via venae cavae. Contraction of left ventricle (simultaneous with step ) forces aortic valve open. 1 2 3 4 5 6 7 8 9 11 9 10 Left pulmonary artery Pulmonary trunk Left pulmonary veins Left atrium Aortic valve Left AV valve Left ventricle 3 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Aorta 5 11 10 5 3 4 6 7 8 6 1 2 11

10. 10 Fig. 19.10 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Left coronary artery (LCA) Right coronary artery (RCA) Right marginal branch of RCA Left auricle (reflected) Circumflex branch of LCA Great cardiac vein Anterior interventricular branch of LCA Right marginal branch of RCA Circumflex branch of LCA Coronary sinus Left marginal branch of LCA Left marginal vein (a) Anterior view(b) Posterior view Right coronary artery (RCA) Posterior interventricular branch of RCA Posterior interventricular vein (c) c: © Visuals Unlimited Great cardiac vein

11. 11 Fig. 19.11 Copyright © McGraw-Hill Education. Permission required for reproduction or display. a: ©Ed Reschke Striations Nucleus Intercalated discs (a) Striated myofibrilIntercalated discs MitochondriaGlycogenNucleus (b) Intercellular space Desmosomes Gap junctions (c)

12. 12 Fig. 19.12 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Right atrium Sinoatrial node (pacemaker) Atrioventricular node Atrioventricular bundle Purkinje fibers Left atrium Bundle branches Purkinje fibers 1 2 2 3 4 5 SA node fires.1 2 3 4 5 Excitation spreads through atrial myocardium. AV node fires. Excitation spreads down AV bundle. Purkinje fibers distribute excitation through ventricular myocardium.

13. 13 Fig. 19.13 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Membrane potential (mV) +10 0 –10 –20 –30 –40 –50 –60 –70 0.4.81.21.6 Time (seconds) Ca 2+ –Na + K+K+ outflow inflow Action potential Pacemaker potential Slow Na + inflow Threshold

14. 14 Fig. 19.14 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Membrane potential (mV) +20 0 –20 –40 –60 –80 0 Time (seconds).30.15 3 4 5 2 1 Plateau 1 2 3 4 5 Voltage-gated Na + channels open. Action potential Myocardial relaxation Myocardial contraction Absolute refractory period Na + inflow depolarizes the membrane and triggers the opening of still more Na + channels, creating a positive feedback cycle and a rapidly rising membrane voltage. Na + channels close when the cell depolarizes, and the voltage peaks at nearly +30 mV. Ca 2+ entering through slow Ca 2+ channels prolongs depolarization of membrane, creating a plateau. Plateau falls slightly because of some K + leakage, but most K + channels remain closed until end of plateau. Ca 2+ channels close and Ca 2+ is transported out of cell. K + channels open, and rapid K + outflow returns membrane to its resting potential.

15. 15 Fig. 19.15 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 0.8 second T wave P wave PQ segment ST segment QRS interval Atria contract Ventricles contract Atria contract Ventricles contract Q S 0 –1 RR Millivolts +1 – PR interval QT interval

16. 16 Fig. 19.16 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Key 1 Ventricular depolarization complete. Wave of depolarization Wave of repolarization Atria begin depolarizing. P Atrial depolarization complete. Ventricular depolarization begins at apex and progresses superiorly as atria repolarize. P R P Q Ventricular repolarization complete; heart is ready for the next cycle. T Q S P R Ventricular repolarization begins at apex and progresses superiorly. Q S T P R Q S P R 2 3 4 5 6

17. 17 Fig. 19.18 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 2 Volume increases Pressure decreases 3 Air flows in P1P1 P 2 > P 1 (a) 1 Volume decreases 2 Pressure increases P1P1 3 Air flows out P2P2 Pressure gradient (b) P 2 < P 1 P2P2

18. 18 Fig. 19.19 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Atrioventricular valves closedAtrioventricular valves open (a) Atrium Atrioventricular valve Ventricle Aorta Pulmonary artery Semilunar valve Semilunar valves closedSemilunar valves open (b)

19. 19 Fig. 19.20 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Diastole Systole Pressure (mm Hg) Ventricular volume (mL) 120 100 80 60 40 20 0 120 90 60 ECG Heart sounds Phase of cardiac cycle Aortic valve closes (dicrotic notch) Aortic valve opens Aortic pressure Left ventricular pressure Left atrial pressure End-diastolic volume End-systolic volume AV valve closes AV valve opens P R T Q S P R Q S S2S2 S3S3 1a Rapid filling 1b Diastasis 1c Atrial systole Isovolumetric contraction Ventricular ejection Isovolumetric relaxation S1S1 S2S2 S3S3 S1S1 1a1b1c2341a1b1c 0.2.4.6.8.2.4 Ventricular filling 234 Time (seconds) 2

20. 20 Fig. 19.21 1 2 3 1 2 3 Right ventricular output exceeds left ventricular output. Pressure backs up. Fluid accumulates in pulmonary tissue. (a) Pulmonary edema 2 1 3 1 2 3 Left ventricular output exceeds right ventricular output. Pressure backs up. Fluid accumulates in systemic tissue. (b) Systemic edema Copyright © McGraw-Hill Education. Permission required for reproduction or display.