Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings C h a p t e r 20 The Heart Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Background Knowledge Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Introduction to Cardiovascular System  Pulmonary Circuit vs Systemic Circuit  Four Chambers of the Heart Right atrium Left atrium Right ventricleLeft ventricle

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Introduction to Cardiovascular System  Three Types of Blood Vessels  Arteries  Carry blood away from heart  Veins  Carry blood to heart  Capillaries  Networks between arteries and veins Are all arteries red? Are all veins blue?

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Figure 20–2c Anatomy of the Heart  Pointed tip is apex  Surrounded by protective “bag” (pericardium)  Sits between two pleural cavities in the mediastinum (cavity)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart Figure 20–3c The Superficial Anatomy of the Heart

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart Figure 20–3b The Superficial Anatomy of the Heart

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  The Heart Wall  Pericardium outside layer  Epicardium (outer layer)  Myocardium (middle layer)  Endocardium (inner layer)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  Cardiac Muscle Tissue  Intercalated discs  Interconnect cardiac muscle cells (SMALL, 1 NUCLEUS)  Secured by desmosomes (force of Contraction)  Linked by gap junctions (pass Action Potentials)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart Figure 20–5 Cardiac Muscle Cells

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  Internal Anatomy and Organization  Septum: wall to separate compartments  Atrioventricular (AV) valves  The fibrous flaps that form bicuspid (2) and tricuspid (3) valves  Permit blood flow in one direction: atria to ventricles The Heart: Valves

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  The Right Atrium (contact with)  Superior vena cava  Receives from head, neck, upper limbs, and chest  Inferior vena cava  Receives from trunk, viscera, and lower limbs

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  The Right Ventricle  chordae tendinae attach to papillary muscles of ventricle  Right atrioventricular (AV) Valve (Tricuspid)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  The Left Atrium  Pulmonary veins deliver to left atrium  Blood from left atrium passes to left ventricle through Bicuspid or left atrioventricular (AV) valve

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  The Left Ventricle  Holds same volume as right ventricle  muscle is thicker and more powerful  Systemic circulation  Blood leaves through semilunar valve to aortic arch

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart Figure 20–7 Structural Differences between the Left and Right Ventricles

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Anatomy of the Heart  The Heart Valves  Semilunar valves  Pulmonary and aortic tricuspid valves  Prevent backflow from pulmonary trunk and aorta into ventricles Figure 20–8 #TAVRmichigan

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Conducting System  The Cardiac Cycle  Begins with action potential at SA node  To AV Node  To Purkinje Fibers  To Cardiac Muscle  Electrocardiogram (ECG)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Conducting System Figure 20–13 Impulse Conduction through the Heart

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Cardiac Cycle Figure 20–18 Heart Sounds  Systole vs Diastole

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Cardiodynamics  Hormonal Effects on Heart Rate  Increase heart rate (stimulation of SA node)  Epinephrine (E)  Norepinephrine (NE)  Thyroid hormone

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Click on Image for Animation

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Heart Conditions  Heart Murmur (Stenotic)  Tachycardia  Myocardial Infarction (Heart Attack)  Ischemic (stroke)  VSD or ASD (septal defect)  Cardiac Arrhythmia  Hemophilia

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Heart Conditions  Heart Murmur (Stenotic)  Sounds produced by regurgitation through valves, leaks  Tachycardia  Abnormally high heart rate  Myocardial Infarction (Heart Attack)  Cut off blood supply to heart  Ischemic (stroke)  Blood flow to brain interrupted  VSD or ASD (septal defect)  Patch hole within 2 years of age, if necessary.  Cardiac Arrhythmia  Irregular heartbeats, once a month or continuous (anxiety, alcohol, drug, medications)  Hemophilia  Fibrin affected by this sex linked trait, prevents proper clotting