1. © 2009 Delmar, Cengage Learning Chapter 13 Heart

2. © 2009 Delmar, Cengage Learning Objectives Describe the functions of the circulatory system List the components of the circulatory system Describe the structure of the heart Describe the function of the various structures of the heart Describe the control of heart contractions Discuss the diseases of the heart Define the key words that relate to this chapter

3. © 2009 Delmar, Cengage Learning Functions of the Circulatory System Heart is the pump that circulates blood Arteries, veins, and capillaries transport the blood Blood carries oxygen and nutrients to the cells and carries the waste products away Lymph system functions

4. © 2009 Delmar, Cengage Learning Major Blood Circuits Blood leaves the heart through arteries and returns by veins Blood circulation routes –General or system circulation –Cardiopulmonary circulation Changes in the composition of circulating blood

5. © 2009 Delmar, Cengage Learning The Heart About the size of a closed fist Weighs about 1 pound Located in thoracic cavity; apex of heart lies on the diaphragm and points to the left of the body After 4 to 5 minutes without blood flow, the brain cells are irreversibly damaged Can hear the heartbeat through the stethoscope Cardiac arrest Cardiopulmonary resuscitation (CPR)

6. © 2009 Delmar, Cengage Learning Structure of the Heart Hollow, muscular, double pump Pericardium and pericardial fluid Myocardium –Cardiac muscle tissue Endocardium Superior and inferior vena cava Coronary sinus Pulmonary artery Pulmonary veins Aorta

7. © 2009 Delmar, Cengage Learning Chambers and Valves Separated into right and left halves by septum; then each half separated into an upper and lower chamber Upper chambers –Left and right atria Low chambers –Left and right ventricles

8. © 2009 Delmar, Cengage Learning Valves Valves keep blood flow going in one direction Atrioventricular valves –Tricuspid valve –Bicuspid or mitral valve Semilunar valves –Pulmonary semilunar valve –Aortic semilunar valve

9. © 2009 Delmar, Cengage Learning Physiology of the Heart Double pump Right heart –Deoxygenated blood Left heart –Oxygenated blood

10. © 2009 Delmar, Cengage Learning Heart Rate and Cardiac Output Normal adult rate is between 72 and 80 beats per minute Stroke volume Calculating the cardiac output Exercise increases cardiac output

11. © 2009 Delmar, Cengage Learning Heart Sounds Valves make a sound when they close Called lubb dupp sounds Lubb –Tricuspid and bicuspid valves (S1) Dupp –Aortic and pulmonary valves (S2)

12. © 2009 Delmar, Cengage Learning Conduction System Electrical impulses cause rhythmic beating of heart Sinoatrial (SA) node or pacemaker Atrioventricular (AV) node Bundle of His Purkinje fibers

13. © 2009 Delmar, Cengage Learning ECG or EKG The electrocardiogram is a device to record the electrical activity of the heart Systole –Contraction Diastole –Relaxation Positive and negative deflection P, QRS, and T waves

14. © 2009 Delmar, Cengage Learning Prevention of Heart Disease Heart disease is the leading cause of death –Coronary heart disease Risk factors Steps to lower risk or prevent heart disease Blood cholesterol levels and triglycerides

15. © 2009 Delmar, Cengage Learning Effects of Aging Heart muscle fibers replaced by fibrous tissue Heart valves increase in thickness Cardiac output decreases Changes become more significant when elderly person becomes physically or mentally stressed

16. © 2009 Delmar, Cengage Learning Diseases of the Heart – Common Symptoms Arrhythmia Bradycardia Tachycardia Murmurs Mitral valve prolapse

17. © 2009 Delmar, Cengage Learning Diseases of the Coronary Artery Coronary artery disease (CAD) Angina pectoris Myocardial infarction

18. © 2009 Delmar, Cengage Learning Infectious Diseases of the Heart Pericarditis Myocarditis Endocarditis Rheumatic heart disease

19. © 2009 Delmar, Cengage Learning Heart Failure When the ventricles of the heart are unable to contract effectively and blood pools in the heart Symptoms depend on which ventricle fails Left ventricle failure –Dyspnea Right ventricle failure –Engorgement of organs, edema and ascites

20. © 2009 Delmar, Cengage Learning Congestive Heart Failure Similar to heart failure plus edema of the lower extremities and blood backs up into the lungs Treatment

21. © 2009 Delmar, Cengage Learning Rhythm/Conduction Defects Heart block –First-degree block –Second-degree block –Third-degree block or complete heart block Premature contractions –PACs –PVCs Fibrillation

22. © 2009 Delmar, Cengage Learning Types of Heart Surgery Angioplasty Coronary bypass Cardiac stents Transmyocardial laser revascularization

23. © 2009 Delmar, Cengage Learning Heart Transplants Used as last resort Problems with heart transplants –Histocompatibility –Organ rejection