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Chapter 14
The Cardiovascular System
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Introduction
• Cardiovascular system - heart, blood and blood vessels
• Cardiac muscle– makes up bulk of heart– provides force to pump blood
• Function - transports blood
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Anatomy of the Heart
• Located in the mediastinum• Surrounded by pericardial sac
– fibrous pericardium - outer layer– serous pericardium - inner layer
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Layers of the Heart Wall
• Epicardium - outermost layer• Pericardial cavity - separates epicardium
and serous pericardium• Myocardium - middle muscular layer• Endocardium - lines the heart
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Chambers of the Heart
• Upper chambers - right and left atria • Lower chambers - right and left ventricles• Chambers separated internally by septum• External separations
– coronary sulcus - separates atria and ventricles
– interventricular sulci - separate ventricles
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Great Vessels of the Heart
• Superior vena cava– receives blood from upper body
• Inferior vena cava– receives blood from lower body
• Coronary sinus - drains blood from heart
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Great Vessels of the Heart
• Pulmonary trunk - right and left artery– carries deoxygenated blood to lungs
• Pulmonary veins (four) - return oxygenated blood to heart
• Ascending Aorta - oxygenated blood out to body– aortic arch, descending thoracic, abdominal
The Valves of the Heart(Preventing Backflow)
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Atrioventricular Valves
• Tricuspid (three cusps)– between right atrium and right ventricle
• Bicuspid (two cusps)– between left atrium and right ventricle
• Cusps attach to ventricles by chordaetendineae
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Semilunar Valves
• Pulmonary– right ventricle– pulmonary trunk exits the heart
• Aortic– left ventricle– ascending aorta leaves the heart
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Blood Flow Through the Heart
The Conduction System of the Heart
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Distribution of Electrical Impulses Through the Heart
• Sinoatrial (SA) node - pacemaker, initiates impulse →
• Atrioventricular (AV) node - sends impulse to AV bundle→
• Bundle of His - sends impulses to both sides of system→
• Purkinje’s fibers - send impulse to myocardial cells
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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A Cardiac Cycle
• One cycle– atria contract / ventricles relax– ventricles contract / atria relax
• Systole - contraction phase• Diastole - relaxation phase
Some Major Blood Circulatory Routes
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Systemic Circulation
• All blood leaving left ventricle (oxygenated)
• All blood returning to right atrium (deoxygenated)
• Subdivisions– coronary circulation– hepatic portal circulation
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Other Circulatory Routes
• Pulmonary - blood flow to lungs for gas exchange
• Cerebral - route to the brain• Fetal - between developing fetus and
mother
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Anatomy of Blood Vessels
• Arteries and veins have three layers– tunica intima - innermost layers– tunica media - middle layer– tunica adventitia - outer layer
• Lumen - blood vessel cavity
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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The Anatomy of Blood Vessels
• Arteries - thicker and stronger than veins• Arterioles - small arteries attach to
capillaries• Capillaries - gas nutrient and waste
exchange• Venules - connect capillaries to veins• Veins - less elastic than arteries, contain
valves
Major Arteries and Veins
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Aorta and Its Branches
• Ascending Aorta - right and left coronary arteries
• Aortic Arch– brachiocephalic, left common carotid artery,
left subclavian artery• Thoracic Aorta• Abdominal Aorta
©2006 by Thomson Delmar Learning, a part of the Thomson Corporation. ALL RIGHTS RESERVED.
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Veins
• Found closer to surface than arteries• Converge with
– superior vena cava– inferior vena cava
• Veins are often named identically to arteries
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