The Heart Happy Friday! #takeoutyournotes #testnotgradedyet
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
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
Chambers of the heart Internal Anatomy of the Heart Right & left atrium Separated by the interatrial septum Right & left ventricle Separated by the interventricular septum
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
The Great Vessels Superior & inferior vena cava Return blood from body to right atrium Coronary Vessels Supplies blood to heart tissue
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 The Great Vessels
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 Valves of the Heart
Valves of the Heart (Ventricular Diastole)
Valves of the Heart (Ventricular Systole)
Coronary Circulation Vessels that supply the myocardium itself Right coronary artery Left coronary artery Cardiac veins
Cast of Coronary Vessels
Pathway of blood flow 1. Deoxygenated blood enters the right atrium 2. Right AV valves opens and blood flows into right ventricle 3. Right AV valve shuts, Right ventricle pumps and blood moves through pulmonary semilunar valve into pulmonary artery 4. Pulmonary semilunar valve shuts blood moves to lungs 5. Oxygenated blood moves through pulmonary vein back to left atrium 6. Left AV valve opens and blood moves into left ventricle 7. Left AV valve shuts and left ventricle contracts 8. Blood moves through aortic semilunar valve into aorta 9. Aortic semilunar valve shuts- oxygenated blood is pumped out to the body
Contraction pattern of the myocardium Determined by the conduction system Systole = contraction Diastole = relaxation Both atria contract Both ventricles contract Atria alternate with ventricles The Cardiac Cycle
Conduction System of the Heart The average heart rate is 72 beats/min. Depolarization stimulates contraction
Conducting System of the Heart Depolarization begins in the sinoatrial (SA) node Pacemaker
Conduction System of the Heart Depolarization spreads through atria, atria contract
Conducting System of the Heart Atrioventricular (AV node) depolarizes Depolarization travels down the AV bundle (bundle of His)
Conducting System of the Heart Depolarization spreads up the ventricular walls via Purkinje fibers. Ventricles contract
Abnormal heart rates Bradycardia Tachycardia Fibrillation Disorders Angina pectoris Myocardial infarction