Chapter Thirteen

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Chapter Thirteen
Unit ThreeCardiovascular Alterations
Fourth Edition Linda D. UrdenKathleen M.
StacyMary E. Lough

• Cardiovascular Anatomy and Physiology

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Anatomy Macroscopic Structure of the Heart

• Structures of the heart
• Position and rotation
• Size and weight
• Layers of the heart
• Pericardium
• Epicardium
• Myocardium
• Endocardium

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Cardiac Chambers

• Atria thin-walled, low pressure chambers
• Contribute 30 of ventricular filling
• Atrial kick
• Ventricles primary pumping forces of the heart
• Thicker stronger left ventricle is the power
  pump
• Thinner right ventricle is the low pressure pump

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Cardiac Valves

• Atrioventricular valves
• Tricuspid and mitral
• Papillary muscles
• Chordae tendineae
• Semilunar valves
• Pulmonic and aortic
• Outflow tracts to great vessels

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Coronary Blood Supply

• Coronary Arteries
• Penetrate epicardium to endocardium
• Left coronary artery divides into left anterior
  descending and left circumflex arteries
• Right coronary artery perfuses the right side of
  the heart and, in most people, the SA and AV
  nodes

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Venous Return from the Heart

• Coronary sinus
• A large vein draining into the right atrium

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Systemic Circulation

• Arterial system resistance vessels
• Blood flow and blood pressure
• Arterioles and vascular resistance
• Capillary bed tissue perfusion
• Single cell endothelium
• Post capillary venules
• Venous system
• 70 of blood volume is in venous system

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Microscopic Structure

• Cardiac fibers
• Myofibrils connected by intercalated discs
• Cardiac cells
• Actin and myosin filaments
• Sarcomere and sarcoplasmic reticulum
• T tubules to enhance conduction
• Increased numbers of mitochondria to provide
  energy

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Physiology

• Properties of Cardiac Tissue
• Excitability
• Conductivity
• Automaticity
• Rhythmicity
• Contractility
• Refractoriness

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Cardiac Cycle

• Ventricular systole
• Isovolumic contraction
• Stroke volume
• Residual or end-systolic volume
• Ejection fraction (EF)
• Ventricular diastole
• Atrial kick

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The Heart and Vessels Cardiac Output

• Cardiac output (CO) the volume of blood ejected
  from the heart over 1 minute
• Stroke volume X heart rate
• Preload
• -LVEDP
• --wedge pressure
• Afterload
• --vasoconstriction

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Regulation of Heartbeat

• Nervous control
• Sympathetic nervous system
• Parasympathetic nervous system
• Intrinsic regulation
• Baroreceptors
• Chemoreceptors
• Bainbridge reflex (atrial stretch)
• Atrial natriuretic factor
• Changes in intrathoracic pressure

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Control of Peripheral Circulation

• Intrinsic control
• Extrinsic control
• Autonomic nervous system
• Vascular reflexes
• Emotions
• Hormones
• Temperature