1. Human Anatomy, 3rd edition Prentice Hall, © 2001 The Heart Chapter 21

2. Human Anatomy, 3rd edition Prentice Hall, © 2001 Introduction –Cardiovascular system – distributes blood Pump (heart) Distribution areas (capillaries) –Heart has 4 compartments 2 receive blood (atria) 2 pump blood out (ventricles) Vessels –Veins return blood to the heart –Arteries take blood away from the heart

3. Human Anatomy, 3rd edition Prentice Hall, © 2001 An Overview of the Circulatory System

4. Human Anatomy, 3rd edition Prentice Hall, © 2001 Superficial Anatomy of the Heart –Atria = “entrance ways” Thin-walled Upper chambers –Ventricles = “hollow spaces” Thick, muscular –Apex points down & tips slightly to the left –Base is superior Great vessels attach

5. Human Anatomy, 3rd edition Prentice Hall, © 2001 Orientation & Superficial Anatomy

6. Human Anatomy, 3rd edition Prentice Hall, © 2001 Anterior View of the Heart

7. Human Anatomy, 3rd edition Prentice Hall, © 2001 Anterior View of the Heart

8. Human Anatomy, 3rd edition Prentice Hall, © 2001 Posterior View of the Heart

9. Human Anatomy, 3rd edition Prentice Hall, © 2001 Posterior View of the Heart

10. Human Anatomy, 3rd edition Prentice Hall, © 2001 The Coverings of the Heart –Pericardium = “around the heart” Visceral pericardium = epicardium Parietal pericardium Pericardial space contains pericardial fluid

11. Human Anatomy, 3rd edition Prentice Hall, © 2001 Pericardium

12. Human Anatomy, 3rd edition Prentice Hall, © 2001 Internal Anatomy of the Heart –Chambers of the heart Right & left atrium –Separated by the interatrial septum Right & left ventricle –Separated by the interventricular septum

13. Human Anatomy, 3rd edition Prentice Hall, © 2001 Structure of the Heart Wall –3 layers Epicardium = “upon the heart” Myocardium is the middle layer –Thickest layer –Cardiac muscle –Has papillary muscles –Chordae tendinae attach flaps of the AV valves to the papillary muscles Endocardium = “inside the heart”

14. Human Anatomy, 3rd edition Prentice Hall, © 2001 Organization of Muscle Tissue

15. Human Anatomy, 3rd edition Prentice Hall, © 2001 Structure of the Heart Wall

16. Human Anatomy, 3rd edition Prentice Hall, © 2001 The Great Vessels –Superior & inferior vena cava Return blood from body to right atrium –Coronary Sinus Returns blood from heart wall to right atrium –Pulmonary artery Takes blood (deoxygenated) from right ventricle to lungs –Pulmonary veins Returns blood (oxygenated) from lungs to left atrium –Aorta Takes blood from left ventricle to body

17. Human Anatomy, 3rd edition Prentice Hall, © 2001 Valves of the Heart –Atrioventricular (AV) valves separate the atria from the ventricles Tricuspid valve – right Bicuspid valve (mitral) – left –Semilunar valves separate the ventricles from the great vessels Pulmonary semilunar valve Aortic semilunar valve –Heart sounds

18. Human Anatomy, 3rd edition Prentice Hall, © 2001 Valves of the Heart (Ventricular Diastole)

19. Human Anatomy, 3rd edition Prentice Hall, © 2001 Valves of the Heart (Ventricular Systole)

20. Human Anatomy, 3rd edition Prentice Hall, © 2001 Heart Sounds

21. Human Anatomy, 3rd edition Prentice Hall, © 2001 Coronary Circulation Vessels that supply the myocardium itself Right coronary artery Left coronary artery Cardiac veins

22. Human Anatomy, 3rd edition Prentice Hall, © 2001 Coronary Circulation

23. Human Anatomy, 3rd edition Prentice Hall, © 2001 Cast of Coronary Vessels

24. Human Anatomy, 3rd edition Prentice Hall, © 2001 The Cardiac Cycle –The contraction pattern of the myocardium Determined by the conduction system –Systole = contraction –Diastole = relaxation –Both atria contract at the same time –Both ventricles contract at the same time –Atria alternate with ventricles

25. Human Anatomy, 3rd edition Prentice Hall, © 2001 The Cardiac Cycle

26. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conduction System of the Heart –The average heart rate is 72 beats/min. –Depolarization stimulates contraction –Depolarization begins in the sinoatrial (SA) node Pacemaker –Depolarization spreads through atria Atria contract –Atrioventricular (AV node) depolarizes –Depolarization travels down the AV bundle (bundle of His) –Depolarization spreads up the ventricular walls via Purkinje fibers. Ventricles contract

27. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conducting System of the Heart

28. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conducting System of the Heart

29. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conduction System of the Heart

30. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conducting System of the Heart

31. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conducting System of the Heart

32. Human Anatomy, 3rd edition Prentice Hall, © 2001 Conducting System of the Heart

33. Human Anatomy, 3rd edition Prentice Hall, © 2001 Electrocardiogram –ECG = a recording of electrical events in the heart P wave = atrial depolarization QRS wave = ventricular depolarization T wave = ventricular repolarization

34. Human Anatomy, 3rd edition Prentice Hall, © 2001 Electrocardiogram

35. Human Anatomy, 3rd edition Prentice Hall, © 2001 Electrocardiogram

36. Human Anatomy, 3rd edition Prentice Hall, © 2001 Disorders –Abnormal heart rates Bradycardia Tachycardia Fibrillation –Angina pectoris –Myocardial infarction