HEARTHEART

Chapter 13

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

FUNCTIONS OF THE FUNCTIONS OF THE CIRCULATORY SYSTEMCIRCULATORY 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

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ORGANS OF THE ORGANS OF THE CIRCULATORY SYSTEMCIRCULATORY SYSTEM

• Heart• Arteries• Veins• Capillaries• Blood• Lymphatic system

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MAJOR BLOOD CIRCUITSMAJOR 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

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THE HEARTTHE HEART

• The heart is the main organ responsible for circulating the blood throughout the body efficiently

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THE HEARTTHE HEART

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STRUCTURE OF THE HEARTSTRUCTURE 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

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STRUCTURE OF THE HEARTSTRUCTURE OF THE HEART

• Structures leading to and from the heart:– Vena cava

•superior and inferior

– Coronary sinus– Pulmonary artery– Pulmonary veins– Aorta

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STRUCTURE OF THE HEARTSTRUCTURE OF THE HEART

• Four chambers of the heart– Right atrium– Left atrium – Right ventricle– Left ventricle

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STRUCTURE OF THE HEARTSTRUCTURE 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 HEARTSTRUCTURE 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

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STRUCTURE OF THE HEARTSTRUCTURE 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

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STRUCTURE OF THE HEARTSTRUCTURE 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

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CONTROL OF HEART CONTROL OF HEART CONTRACTIONSCONTRACTIONS

• 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

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DIAGNOSTIC TESTS FOR HEART DIAGNOSTIC TESTS FOR HEART AND CIRCULATORY FUNCTIONAND 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

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DISEASES OF THE HEARTDISEASES OF THE HEART

• Common symptoms of heart disease– Arrhythmia– Bradycardia– Tachycardia– Murmurs– Mitral valve prolapse

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DISEASES OF THE HEARTDISEASES 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

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DISEASES OF THE HEARTDISEASES OF THE HEART

• Infectious diseases of the heart– Pericarditis– Myocarditis– Endocarditis– Rheumatic heart disease

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DISEASES OF THE HEARTDISEASES 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

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DISEASES OF THE HEARTDISEASES 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

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TYPES OF HEART SURGERYTYPES OF HEART SURGERY

• Angioplasty (balloon surgery)• Coronary bypass• Cardiac stints• Transmyocardial laser

revascularization (TMR)

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HEART TRANSPLANTSHEART 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