1. The Heart
Chapter 20

2. Human Anatomy, 3rd edition
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

3. 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

4. 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

5. 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

6. Structure of the Heart Wall
Epicardium = “upon the heart”
Myocardium is the middle layer
Cardiac muscle
Papillary muscles
Chordae tendinae attach AV valves to the papillary muscles
Endocardium = “inside the heart”
Human Anatomy, 3rd edition
Prentice Hall, © 2001

7. Human Anatomy, 3rd edition
The Great Vessels
Superior & inferior vena cava
Return blood from body to right atrium
Coronary Sinus
Returns blood from heart wall to right atrium
Human Anatomy, 3rd edition
Prentice Hall, © 2001

8. Human Anatomy, 3rd edition
The Great Vessels
Pulmonary veins
Return blood (oxygenated) from lungs to left atrium
Aorta
Takes blood from left ventricle to body
Pulmonary artery
Takes blood (deoxygenated) from right ventricle to lungs
Human Anatomy, 3rd edition
Prentice Hall, © 2001

9. Human Anatomy, 3rd edition
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

10. Valves of the Heart (Ventricular Diastole)
FG21_07A.JPG
Title: Valves of the Heart
Notes: (a)Valve position during ventricular diastole; AV valves open, semilunar valves closed. (b)Cardiac valves during ventricular systole; AV valves closed, semilunar valves open. Note how chordae tendineae and papillary muscles affect movement of AV valve.
Keywords: heart, valves, ventricular systole, tricuspid, fibrous skeleton, mitral valve, aortic semilunar, pulmonary semilunar, chordae tendineae, ventricle, papillary muscles
Human Anatomy, 3rd edition
Prentice Hall, © 2001

11. Valves of the Heart (Ventricular Systole)
FG21_07B.JPG
Title: Valves of the Heart
Notes: (c)Superior view of heart valves. (d)Proper placement of a stethoscope varies depending on which heart sounds and valves are of interest.
Keywords: heart, valves, pulmonary valve, aortic valve, mitral, atrium, vena cava, aorta, pulmonary trunk, heart sounds, stethoscope, aortic semilunar, pulmonary semilunar, mitral, tricuspid
Human Anatomy, 3rd edition
Prentice Hall, © 2001

12. Human Anatomy, 3rd edition
Coronary Circulation
Vessels that supply the myocardium itself
Right coronary artery
Left coronary artery
Cardiac veins
Human Anatomy, 3rd edition
Prentice Hall, © 2001

13. Cast of Coronary Vessels
FG21_09C.JPG
Title: Coronary Circulation
Notes: (a)Vessels supplying anterior surface of heart. (b)Coronary vessels supplying posterior surface of heart. (c)Cast of coronary vessels. (d)Coronary angiogram, left lateral projection.
Keywords: coronary, circulation, anterior, artery, vein, circumflex branch, anterior interventricular branch, great cardiac vein, marginal branch, posterior interventricular branch, middle cardiac vein, right coronary artery, small cardiac vein, coronary sinus
Human Anatomy, 3rd edition
Prentice Hall, © 2001

14. Human Anatomy, 3rd edition
The Cardiac Cycle
Contraction pattern of the myocardium
Determined by the conduction system
Systole = contraction
Diastole = relaxation
Both atria contract
Both ventricles contract
Atria alternate with ventricles
Human Anatomy, 3rd edition
Prentice Hall, © 2001

15. Conduction System of the Heart
The average heart rate is 72 beats/min.
Depolarization stimulates contraction
Human Anatomy, 3rd edition
Prentice Hall, © 2001

16. Conducting System of the Heart
Depolarization begins in the sinoatrial (SA) node
Pacemaker
FG21_12B.JPG
Title: The Conducting System of the Heart
Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction.
Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers
Human Anatomy, 3rd edition
Prentice Hall, © 2001

17. Conduction System of the Heart
Depolarization spreads through atria, atria contract
FG21_12C.JPG
Title: The Conducting System of the Heart
Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction.
Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers

18. Conducting System of the Heart
Atrioventricular (AV node) depolarizes
Depolarization travels down the AV bundle (bundle of His)
FG21_12E.JPG
Title: The Conducting System of the Heart
Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction.
Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers
Human Anatomy, 3rd edition
Prentice Hall, © 2001

19. Conducting System of the Heart
Depolarization spreads up the ventricular walls via Purkinje fibers.
Ventricles contract
FG21_12F.JPG
Title: The Conducting System of the Heart
Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction.
Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers
Human Anatomy, 3rd edition
Prentice Hall, © 2001

20. Disorders Abnormal heart rates Angina pectoris Myocardial infarction
Bradycardia
Tachycardia
Fibrillation
Angina pectoris
Myocardial infarction