Chapter 18: Cardiovascular System: The Heart

Dr. Norman E. Shumway – performed the first heart transplant in the United States in The 54-year-old recipient, whose heart had been damaged by virus infection, survived 15 days following surgery.

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.3: The circular and spiral arrangement of cardiac muscle bundles in the myocardium of the heart, p Cardiac muscle bundles

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.4a: Gross anatomy of the heart, p (a) Right atrium Anterior interventricular artery Right ventricle Aortic arch (fat covered) Left auricle of left atrium Apex of heart (left ventricle) Pulmonary trunk

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.4b: Gross anatomy of the heart, p (b) Brachiocephalic trunk Superior vena cava Right pulmonary artery Ascending aorta Pulmonary trunk Right pulmonary veins Right atrium Right coronary artery (in coronary sulcus) Anterior cardiac vein Right ventricle Marginal artery Small cardiac vein Inferior vena cava Left common carotid artery Left subclavian artery Aortic arch Ligamentum arteriosum Left pulmonary artery Left atrium Auricle Circumflex artery Left coronary artery (in coronary sulcus) Anterior interventricular artery (in anterior interventricular sulcus) Great cardiac vein Apex Left pulmonary veins Left ventricle

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.4d: Gross anatomy of the heart, p (d) Superior vena cava Right pulmonary artery Right pulmonary veins Right atrium Right coronary artery (in coronary sulcus) Right ventricle Coronary sinus Middle cardiac vein Left pulmonary artery Left atrium Auricle of left atrium Left ventricle Posterior vein of left ventricle Posterior interventricular artery (in posterior interventricular sulcus) Great cardiac vein Apex Left pulmonary veins Inferior vena cava Aorta

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.4e: Gross anatomy of the heart, p (e) Superior vena cava Right pulmonary artery Pulmonary trunk Right atrium Right pulmonary veins Fossa ovalis Pectinate muscles Tricuspid valve Right ventricle Chordae tendineae Trabeculae carneae Inferior vena cava Aorta Left pulmonary artery Left atrium Left pulmonary veins Pulmonary valve Aortic valve Mitral (bicuspid) valve Left ventricle Papillary muscle Interventricular septum Myocardium Visceral pericardium Endocardium

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.5: The systemic and pulmonary circuits, p Capillary beds of lungs where gas exchange occurs Capillary beds of all body tissues where gas exchange occurs Pulmonary veins Pulmonary arteries Pulmonary Circuit Systemic Circuit Aorta and branches Left atrium Heart Left ventricle Right atrium Right ventricle Venae cavae Key: = Oxygen-rich, CO 2 -poor blood = Oxygen-poor, CO 2 -rich blood

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.6: Anatomical differences in right and left ventricles, p Right ventricle Left ventricle Muscular interventricular septum

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.7: Coronary circulation, p (a)(b) Right ventricle Right coronary artery Right atrium Marginal artery Posterior interventricular artery Anterior interventricular artery Circumflex artery Left coronary artery Aorta Anastomosis (junction of vessels) Left ventricle Superior vena cava Left atrium Pulmonary trunk Superior vena cava Anterior cardiac veins Small cardiac veinMiddle cardiac vein Great cardiac vein Coronary sinus

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.11: Microscopic anatomy of cardiac muscle, p Intercalated disc Nucleus Desmosome Gap junctions Intercalated discs Sarcolemma I bandA band Cardiac muscle cell Sarcolemma Z disc Mitochondrion T tubule Sarcoplasmic reticulum I band (b) (a)

William Einthoven – invented the electrocardiograph and awarded the nobel prize in 1924

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.16: An electrocardiogram tracing (lead I), p Sinoatrial node Atrioventricular node QRS complex Atrial depolarization Ventricular depolarization Ventricular repolarization P-Q Interval S-T Segment P R Q S T Q-T Interval Time (s)

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.17: The sequence of excitation of the heart related to the deflection waves of an ECG tracing, p SA node generates impulse; atrial excitation begins Impulse delayed at AV node Impulse passes to heart apex; ventricular excitation begins Ventricular excitation complete SA node AV nodePurkinje fibers Bundle branches

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.19: Areas of the thoracic surface where the heart sounds can be best detected, p Sounds of tricuspid valve are typically heard in right sternal margin of 5th intercostal space; variations include over sternum or over left sternal margin in 5th intercostal space. Sounds of aortic valve are heard in 2nd intercostal space at right sternal margin. Sounds of pulmonary valve are heard in 2nd intercostal space at left sternal margin. Sounds of mitral valve are heard over heart apex, in 5th intercostal space in line with middle of clavicle.

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.24: Development of the human heart during week 4, p Heart twists Arterial end Venous end Atrium Ventricle Aorta Superior vena cava Inferior vena cava Ductus arteriosus Pulmonary trunk Foramen ovale Ventricle Endothelial tubes begin to fuse Arterial end Venous end Ventricle Tubular heart 4a (d) (e) (a)(b)(c)

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 18.25: Three examples of congenital heart defects, p Occurs in about 1 in every 500 births Occurs in about 1 in every 1500 births Narrowed aorta Occurs in about 1 in every 2000 births Ventricular septal defect. The superior part of the inter- ventricular septum fails to form; thus, blood mixes between the two ventricles, but because the left ventricle is stronger, more blood is shunted from left to right. (a)Coarctation of the aorta. A part of the aorta is narrowed, increasing the workload on the left ventricle. (b)Tetralogy of Fallot. Multiple defects (tetra = four): Pulmonary trunk too narrow and pulmonary valve stenosed, resulting in a hypertrophied right ventricle; ventricular septal defect; aorta opens from both ventricles; wall of right ventricle thickened from overwork. (c)