Chapter 13 HEART 2004 Delmar Learning a Division

Chapter 13 HEART © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

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.

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.

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.

THE HEART © 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.

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.

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.

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.

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.

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.

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.

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.

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.

DISEASES OF THE HEART • Infectious diseases of the heart – Pericarditis – Myocarditis – Endocarditis – Rheumatic heart disease © 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.

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.

TYPES OF HEART SURGERY • • Angioplasty (balloon surgery) Coronary bypass Cardiac stints Transmyocardial laser revascularization (TMR) © 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.