Chapter 18: Cardiovascular System: The Heart

1. Chapter 18: Cardiovascular System: The Heart

2. Dr. Norman E. Shumway – performed the first heart transplant in the United States in 1968. The 54-year-old recipient, whose heart had been damaged by virus infection, survived 15 days following surgery.

3. Figure 18.3: The circular and spiral arrangement of cardiac muscle bundles in the myocardium of the heart, p. 680. Cardiac muscle bundles

4. Figure 18.4a: Gross anatomy of the heart, p. 681. Aortic arch (fat covered) Pulmonary trunk Right atrium Left auricle of left atrium Anterior interventricular artery Right ventricle Apex of heart (left ventricle) (a)

5. Figure 18.4b: Gross anatomy of the heart, p. 681. Left common carotid artery Brachiocephalic trunk Left subclavian artery Superior vena cava Aortic arch Right pulmonary artery Ligamentum arteriosum Left pulmonary artery Ascending aorta Left pulmonary veins Pulmonary trunk Left atrium Right pulmonary veins Auricle Right atrium Circumflex artery Right coronary artery (in coronary sulcus) Left coronary artery (in coronary sulcus) Anterior cardiac vein Left ventricle Right ventricle Great cardiac vein Marginal artery Anterior interventricular artery (in anterior interventricular sulcus) Small cardiac vein Inferior vena cava (b) Apex

6. Figure 18.4d: Gross anatomy of the heart, p. 682. Aorta Superior vena cava Left pulmonary artery Right pulmonary artery Left pulmonary veins Right pulmonary veins Auricle of left atrium Right atrium Left atrium Inferior vena cava Great cardiac vein Right coronary artery (in coronary sulcus) Posterior vein of left ventricle Coronary sinus Posterior interventricular artery (in posterior interventricular sulcus) Left ventricle Middle cardiac vein Apex Right ventricle (d)

7. Figure 18.4e: Gross anatomy of the heart, p. 683. Aorta Superior vena cava Left pulmonary artery Right pulmonary artery Left atrium Pulmonary trunk Left pulmonary veins Right atrium Right pulmonary veins Mitral (bicuspid) valve Fossa ovalis Aortic valve Pectinate muscles Pulmonary valve Left ventricle Tricuspid valve Papillary muscle Right ventricle Chordae tendineae Interventricular septum Myocardium Trabeculae carneae Visceral pericardium Inferior vena cava Endocardium (e)

8. Figure 18.5: The systemic and pulmonary circuits, p. 684. Capillary beds of lungs where gas exchange occurs Pulmonary Circuit Pulmonary arteries Pulmonary veins Aorta and branches Venae cavae Left atrium Left ventricle Right atrium Heart Right ventricle Systemic Circuit Key: Capillary beds of all body tissues where gas exchange occurs = Oxygen-rich, CO2-poor blood = Oxygen-poor, CO2-rich blood

9. Figure 18.6: Anatomical differences in right and left ventricles, p. 685. Left ventricle Right ventricle Muscular interventricular septum

10. Figure 18.7: Coronary circulation, p. 685. Aorta Superior vena cava Pulmonary trunk Left coronary artery Anastomosis (junction of vessels) Superior vena cava Left atrium Right coronary artery Circumflex artery Great cardiac vein Anterior cardiac veins Right ventricle Right atrium Coronary sinus Left ventricle Marginal artery Posterior interventricular artery Anterior interventricular artery Small cardiac vein Middle cardiac vein (a) (b)

11. Figure 18.11: Microscopic anatomy of cardiac muscle, p. 690. Intercalated discs Nucleus Cardiac muscle cell Desmosome Desmosome Gap junctions (a) Mitochondrion Nucleus Cardiac muscle cell Sarcoplasmic reticulum T tubule Nucleus I n t e r c a l a t e d d i s c S a r c o l e m m a ( b ) Z disc Sarcolemma I band A b a n d I band Mitochondrion

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

13. Figure 18.16: An electrocardiogram tracing (lead I), p. 696. QRS complex R Sinoatrial node Ventricular depolarization Atrioventricular node Ventricular repolarization Atrial depolarization T P Q P-Q Interval S-T Segment S Time (s) 0 0.2 0.4 0.6 0.8 Q-T Interval

18. Figure 18.17: The sequence of excitation of the heart related to the deflection waves of an ECG tracing, p. 696. SA node generates impulse; atrial excitation begins Impulse delayed at AV node Impulse passes to heart apex; ventricular excitation begins Ventricular excitation complete AV node Bundle branches Purkinje fibers SA node

19. Figure 18.19: Areas of the thoracic surface where the heart sounds can be best detected, p. 697. 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. 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.

20. Figure 18.24: Development of the human heart during week 4, p. 705. Ductus arteriosus Aorta Endothelial tubes begin to fuse Superior vena cava Pulmonary trunk Arterial end Arterial end Foramen ovale 4a 4 Tubular heart Ventricle Ventricle Atrium 3 2 Inferior vena cava 1 Ventricle Venous end Venous end (e) (a) (b) (c) (d) Heart twists

21. Figure 18.25: Three examples of congenital heart defects, p. 708. Narrowed aorta Occurs in about 1 in every 500 births Occurs in about 1 in every 1500 births Occurs in about 1 in every 2000 births (a) 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. (b) Coarctation of the aorta. A part of the aorta is narrowed, increasing the workload on the left ventricle. (c) 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.