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Heart
Figure 22.02b
Heart
Functions of the Heart
Ensures unidirectional flow of blood
Pumps blood to lungs and body
Develops blood pressure for nutrient and waste exchange
Figure 22.01
Heart-Anatomical Location and Orientation
Heart Anatomical Orientation and Location
Chambers of the Heart
• Atria • (Left and
Right)
• Ventricles (Left and Right)
Heart Valves
• Atrioventricular (AV) valves – between atria and ventricles
• Semilumar Valves– between ventricles and great arteries
Valves of the Heart
Heart Valves
Figure 18.8a
Atrioventricular Valves (Open)
Atrioventricular Valves (Closed)
Figure 18.9b
Semilunar Valves (Open vs Closed)
Figure 18.10a, b
Pericardium
Layers of the Heart
Layers of the Heart
Figure 18.3
EpicardiumMyocardiumEndocardium
Cardiac Muscle Cells
Cardiac Muscle Cells
Blood Flow Through the Heart
Figure 22.06ab
Conduction System
• Cardiac muscle tissue has intrinsic ability to:
• Generate and conduct impulses
• Signal these cells to contract rhythmically
• Conducting system
• A series of specialized cardiac muscle cells
• Sinoatrial (SA) node sets the inherent rate of contraction
Conducting System
Figure 18.12
Conduction System
Conduction System and ECGs
Conduction System of Heart
Disorders of the Heart
• Coronary artery disease
• Atherosclerosis – fatty deposits
• Angina pectoris – chest pain
• Myocardial infarction – blocked coronary artery
• Silent ischemia – no pain or warning
Disorders of the Heart
• Heart failure• Progressive weakening of the heart• Cannot meet the body’s demands for
oxygenated blood
• Congestive heart failure – heart enlarges• Pumping efficiency declines
• Cor pulmonale • Enlargement and potential failure of the right
ventricle
Disorders of Conduction
• Ventricular fibrillation
• Rapid, random firing of electrical impulses in the ventricles
• Atrial fibrillation
• Multiple waves of impulses randomly signal the AV node
• Signals ventricles to contract quickly and irregularly