PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 18 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Heart PART 1
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Heart A muscular double pump Pulmonary circuit – takes blood to and from the lungs Systemic circuit – vessels transport blood to and from body tissues Atria – receive blood from the pulmonary and systemic circuits Ventricles – the pumping chambers of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Pulmonary and Systemic Circuits Figure 18.1
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Location and Orientation within the Thorax Heart – typically weighs 250–350 grams (healthy heart) Largest organ of the mediastinum Located between the lungs Apex lies to the left of the midline Base is the broad posterior surface
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Location and Orientation within the Thorax Figure 18.2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Four “Corners” of the Heart Superior right At costal cartilage of third rib and sternum Inferior right At costal cartilage of sixth rib lateral to the sternum Superior left At costal cartilage of second rib lateral to the sternum Inferior left Lies in the fifth intercostal space at the midclavicular line
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Location and Orientation within the Thorax Figure 18.2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Coverings Pericardium – two primary layers Fibrous pericardium Strong layer of dense connective tissue Serous pericardium Formed from two layers Parietal pericardium Visceral pericardium
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Coverings Figure 18.3
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Layers of the Heart Wall Epicardium Visceral layer of the serous pericardium Myocardium Consists of cardiac muscle Muscle arranged in circular and spiral patterns Endocardium Endothelium resting on a layer of connective tissue Lines the internal walls of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Layers of the Heart Wall Figure 18.4
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings PLAY Rotatable Heart Heart Chambers Right and left atria Superior chambers Right and left ventricles Inferior chambers Internal divisions Interventricular septa Interatrial septa External markings Coronary sulcus Anterior interventricular sulcus posterior interventricular sulcus
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Chambers Figure 18.5b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Right Atrium Forms right border of heart Receives blood from systemic circuit Pectinate muscles Ridges inside anterior of right atrium Crista terminalis Landmark used to locate veins entering right atrium Fossa ovalis Depression in interatrial septum Remnant of foramen ovale
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Right Ventricle Receives blood from right atrium through the tricuspid valve Pumps blood into pulmonary circuit via Pulmonary trunk Internal walls of right ventricle Trabeculae carneae Papillary muscles Chordae tendineae
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Left Atrium Makes up heart’s posterior surface Receives oxygen-rich blood from lungs Opens into the left ventricle through Mitral valve (left atrioventricular valve)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Left Ventricle Forms apex of the heart Internal walls of left ventricle Trabeculae carneae Papillary muscles Chordae tendineae Pumps blood through systemic circuit via Aortic semilunar valve (aortic valve) PLAY Rotatable Heart Section
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Chambers Figure 18.5e
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Inferior View of the Heart Figure 18.5d
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pathway of Blood Through the Heart Beginning with oxygen-poor blood in the superior and inferior venae cavae Go through pulmonary and systemic circuits A blood drop passes through all structures sequentially Atria contract together Ventricles contract together
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Blood Flow Through the Heart Figure 18.6
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pathway of Blood Through the Heart Figure 18.6b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heartbeat 70 – 80 beats per minute at rest Systole – contraction of a heart chamber Diastole – expansion of a heart chamber Systole and diastole also refer to Stage of heartbeat when ventricles contract and expand
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Heart Wall Walls differ in thickness Atria – thin walls Ventricles – thick walls Systemic circuit Longer than pulmonary circuit Offers greater resistance to blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Heart Wall Left ventricle – three times thicker than right Exerts more pumping force Flattens right ventricle into a crescent shape Figure 18.7
PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 18 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Heart PART 2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Heart A muscular double pump Pulmonary circuit – takes blood to and from the lungs Systemic circuit – vessels transport blood to and from body tissues Atria – receive blood from the pulmonary and systemic circuits Ventricles – the pumping chambers of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Pulmonary and Systemic Circuits Figure 18.1
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Location and Orientation within the Thorax Heart – typically weighs 250–350 grams (healthy heart) Largest organ of the mediastinum Located between the lungs Apex lies to the left of the midline Base is the broad posterior surface
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Location and Orientation within the Thorax Figure 18.2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Four “Corners” of the Heart Superior right At costal cartilage of third rib and sternum Inferior right At costal cartilage of sixth rib lateral to the sternum Superior left At costal cartilage of second rib lateral to the sternum Inferior left Lies in the fifth intercostal space at the midclavicular line
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Location and Orientation within the Thorax Figure 18.2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Coverings Pericardium – two primary layers Fibrous pericardium Strong layer of dense connective tissue Serous pericardium Formed from two layers Parietal pericardium Visceral pericardium
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Coverings Figure 18.3
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Layers of the Heart Wall Epicardium Visceral layer of the serous pericardium Myocardium Consists of cardiac muscle Muscle arranged in circular and spiral patterns Endocardium Endothelium resting on a layer of connective tissue Lines the internal walls of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Heart – Layers of the Heart Wall Figure 18.4
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings PLAY Rotatable Heart Heart Chambers Right and left atria Superior chambers Right and left ventricles Inferior chambers Internal divisions Interventricular septa Interatrial septa External markings Coronary sulcus Anterior interventricular sulcus posterior interventricular sulcus
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Chambers Figure 18.5b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Right Atrium Forms right border of heart Receives blood from systemic circuit Pectinate muscles Ridges inside anterior of right atrium Crista terminalis Landmark used to locate veins entering right atrium Fossa ovalis Depression in interatrial septum Remnant of foramen ovale
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Right Ventricle Receives blood from right atrium through the tricuspid valve Pumps blood into pulmonary circuit via Pulmonary trunk Internal walls of right ventricle Trabeculae carneae Papillary muscles Chordae tendineae
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Left Atrium Makes up heart’s posterior surface Receives oxygen-rich blood from lungs Opens into the left ventricle through Mitral valve (left atrioventricular valve)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Left Ventricle Forms apex of the heart Internal walls of left ventricle Trabeculae carneae Papillary muscles Chordae tendineae Pumps blood through systemic circuit via Aortic semilunar valve (aortic valve) PLAY Rotatable Heart Section
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Chambers Figure 18.5e
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Inferior View of the Heart Figure 18.5d
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pathway of Blood Through the Heart Beginning with oxygen-poor blood in the superior and inferior venae cavae Go through pulmonary and systemic circuits A blood drop passes through all structures sequentially Atria contract together Ventricles contract together
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Blood Flow Through the Heart Figure 18.6
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pathway of Blood Through the Heart Figure 18.6b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heartbeat 70 – 80 beats per minute at rest Systole – contraction of a heart chamber Diastole – expansion of a heart chamber Systole and diastole also refer to Stage of heartbeat when ventricles contract and expand
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Heart Wall Walls differ in thickness Atria – thin walls Ventricles – thick walls Systemic circuit Longer than pulmonary circuit Offers greater resistance to blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Heart Wall Left ventricle – three times thicker than right Exerts more pumping force Flattens right ventricle into a crescent shape Figure 18.7
PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 18 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Heart PART 3
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Valves – Valve Structure Each valve composed of Endocardium with connective tissue core Atrioventricular (AV) valves Between atria and ventricles Aortic and pulmonary valves At junction of ventricles and great arteries
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Fibrous Skeleton Surrounds all four valves Composed of dense connective tissue Functions Anchors valve cusps Prevents overdilation of valve openings Main point of insertion for cardiac muscle Blocks direct spread of electrical impulses
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Valves – Valve Structure Figure 18.8a
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Function of the Atrioventricular Valves Figure 18.9a
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Function of the Atrioventricular Valves Figure 18.9b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Function of the Semilunar Valves Figure 18.10a, b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Sounds “Lub-dup” – sound of valves closing First sound “lub” The AV valves closing Second sound “dup” The semilunar valves closing
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Sounds Figure 18.8a
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Sounds Each valve sound – best heard near a different heart corner Pulmonary valve – superior left corner Aortic valve – superior right corner Mitral (bicuspid) valve– at the apex Tricuspid valve – inferior right corner
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Heart Sounds Figure 18.11
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Forms a thick layer called myocardium Striated like skeletal muscle Contractions pump blood through the heart and into blood vessels Contracts by sliding filament mechanism
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Cardiac muscle cells Short Branching Have one or two nuclei Not fused colonies like skeletal muscle
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Cells join at intercalated discs Complex junctions Form cellular networks Cells are separated by delicate endomysium Binds adjacent cardiac fibers Contains blood vessels and nerves
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Intercalated discs – complex junctions Adjacent sarcolemmas interlock Possess three types of cell junctions Desmosomes Fasciae adherans – long desmosome-like junctions Gap junctions
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Anatomy of Cardiac Muscle Figure 18.12a, b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Figure 18.12c, d
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Triggered to contract by Ca 2+ entering the sarcoplasm Signals sarcoplasmic reticulum to release Ca 2+ ions Ions diffuse into sarcomeres Trigger sliding filament mechanism
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cardiac Muscle Tissue Not all cardiac cells are innervated Will contract in rhythmic manner without innervation Inherent rhythmicity Is the basis for rhythmic heartbeat
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Conducting 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
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Conducting System Figure 18.14
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Innervation Heart rate is altered by external controls Nerves to the heart include Visceral sensory fibers Parasympathetic branches of the vagus nerve Sympathetic fibers – from cervical and upper thoracic chain ganglia Figure 18.15
PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 18 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Heart PART 4
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Blood Supply to the Heart Functional blood supply Coronary arteries Arise from the aorta Located in the coronary sulcus Main branches Left and right coronary arteries
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Blood Supply to the Heart Figure 18.16
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Disorders of the Heart Coronary artery disease Atherosclerosis – fatty deposits Angina pectoris – chest pain Myocardial infarction – blocked coronary artery Heart attack Silent ischemia – no pain or warning
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Disorders of the Heart Heart failure Progressive weakening of the heart Cannot meet the body’s demands for oxygenated blood Congestive heart failure (CHF) Heart enlarges Pumping efficiency declines Cor pulmonale Enlargement and potential failure of right ventricle