Chapter 13 HEART

FUNCTIONS OF THE CIRCULATORY SYSTEM Heart pumps and circulates blood to all parts of the body Blood vessels circulate blood between heart and cells Blood carries oxygen and nutrients to cells and carries away wastes Lymph system returns excess fluids from tissues and makes lymphocytes © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

ORGANS OF THE CIRCULATORY SYSTEM Heart Arteries Veins Capillaries Blood Lymphatic system © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. MAJOR BLOOD CIRCUITS Blood leaves the heart through arteries and returns to the heart from veins The general (systemic) circulation carries blood throughout the body Cardiopulmonary circulation carries blood from the heart to lungs and back © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. THE HEART The heart is the main organ responsible for circulating the blood throughout the body efficiently © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. THE HEART © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART The heart is a hollow, muscular, double pump Pericardium - double layer of fibrous tissues surrounding heart Myocardium - cardiac muscle tissue Endocardium - Smooth inner lining Septum - Muscular wall separating heart into two halves © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART Structures leading to and from the heart: Vena cava superior and inferior Coronary sinus Pulmonary artery Pulmonary veins Aorta © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART Four chambers of the heart Right atrium Left atrium Right ventricle Left ventricle © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART Four valves permit blood flow in only one direction Tricuspid valve Bicuspid (mitral) valve Pulmonary semilunar valve Aortic semilunar valve © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART Two major functions occur with each heart beat Right heart: Blood is taken to the lungs for oxygen Left heart: Blood is taken from lungs to be circulated throughout body The heart receives its blood supply from the coronary artery © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART Stroke volume: Number of heart beats per minute The heart at rest beats between 72 and 80 times per minute Cardiac output: The amount of blood ejected from heart per minute Between 60 and 80 ml of blood on average © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. STRUCTURE OF THE HEART Lubb dupp sounds - Sounds made by the valves during the cardiac cycle Lubb - sound made when the tricuspid and bicuspid valves close between the atria and ventricles Dupp - Caused by semilunar valves in the aorta and the pulmonary artery closing © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

CONTROL OF HEART CONTRACTIONS Pacemaker (sinoatrial node) Conducting cells found at the opening of the superior vena cava that control heart muscle contractions Sends out electrical impulses that begin and regulate the heart Electrocardiogram (ECG or EKG) Records electrical activity of heart © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

DIAGNOSTIC TESTS FOR HEART AND CIRCULATORY FUNCTION Cardiac catheterization is the insertion of a catheter into the femoral artery or vein Dye is inserted and pictures are taken as fluid moves through the heart Stress tests determine how physiological stress and exercise affect the heart © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. DISEASES OF THE HEART Common symptoms of heart disease Arrhythmia Bradycardia Tachycardia Murmurs Mitral valve prolapse © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. DISEASES OF THE HEART Coronary Artery disease (CAD) Narrowing of the arteries that supply oxygen and nutrients to the heart Angina pectoris - severe chest pain from inadequate oxygen to heart Myocardial infarction (heart attack) - caused by lack of blood supply to heart © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. DISEASES OF THE HEART Infectious diseases of the heart Pericarditis Myocarditis Endocarditis Rheumatic heart disease © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. DISEASES OF THE HEART Prevention of heart disease Not smoking Regular exercise Maintaining ideal weight Estrogen replacement therapy Reduction of triglyceride and cholesterol levels Maintaining normal blood pressure © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. DISEASES OF THE HEART Congestive heart failure is similar to heart failure but includes edema in lower extremities Rhythm/Conduction defects Heart block Premature contractions Fibrillation © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. TYPES OF HEART SURGERY Angioplasty (balloon surgery) Coronary bypass Cardiac stints Transmyocardial laser revascularization (TMR) © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

© 2004 Delmar Learning, a Division of Thomson Learning, Inc. HEART TRANSPLANTS Heart transplant is needed when individual’s heart can no longer function properly Organ rejection may occur even when tissue type is matched Immunosuppressants are drugs used to suppress recipient’s immune system from rejecting donor organ © 2004 Delmar Learning, a Division of Thomson Learning, Inc.