Transcript Visceral pericardium

The Heart
Chapter 21
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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
An Overview of the Circulatory System
Human Anatomy, 3rd edition
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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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Orientation & Superficial Anatomy
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Anterior View of the Heart
Human Anatomy, 3rd edition
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Anterior View of the Heart
Human Anatomy, 3rd edition
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Posterior View of the Heart
Human Anatomy, 3rd edition
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Posterior View of the Heart
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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Pericardium
Human Anatomy, 3rd edition
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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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Structure of the Heart Wall
– 3 layers
• Epicardium = “upon the heart”
• Myocardium is the middle layer
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Thickest layer
Cardiac muscle
Has papillary muscles
Chordae tendinae attach flaps of the AV valves to the
papillary muscles
• Endocardium = “inside the heart”
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Organization of Muscle Tissue
Human Anatomy, 3rd edition
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Structure of the Heart Wall
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
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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Valves of the Heart (Ventricular Diastole)
Human Anatomy, 3rd edition
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Valves of the Heart (Ventricular Systole)
Human Anatomy, 3rd edition
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Heart Sounds
Human Anatomy, 3rd edition
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Coronary Circulation
Vessels that supply the myocardium itself
Right coronary artery
Left coronary artery
Cardiac veins
Human Anatomy, 3rd edition
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Coronary Circulation
Human Anatomy, 3rd edition
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Cast of Coronary Vessels
Human Anatomy, 3rd edition
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The Cardiac Cycle
– The contraction pattern of the myocardium
• Determined by the conduction system
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Systole = contraction
Diastole = relaxation
Both atria contract at the same time
Both ventricles contract at the same time
Atria alternate with ventricles
Human Anatomy, 3rd edition
Prentice Hall, © 2001
The Cardiac Cycle
Human Anatomy, 3rd edition
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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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Conducting System of the Heart
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Conducting System of the Heart
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Conduction System of the Heart
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Conducting System of the Heart
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Conducting System of the Heart
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Conducting System of the Heart
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
Human Anatomy, 3rd edition
Prentice Hall, © 2001
Electrocardiogram
Human Anatomy, 3rd edition
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Electrocardiogram
Human Anatomy, 3rd edition
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Disorders
– Abnormal heart rates
• Bradycardia
• Tachycardia
• Fibrillation
– Angina pectoris
– Myocardial infarction
Human Anatomy, 3rd edition
Prentice Hall, © 2001