Biology 2122 – Review – The Heart and Cardiovascular System (Chapter 18) Vocabulary: pericardium; epicardium; myocardium; endocardium; atria; ventricles; septum; auricles; fossa ovalis; vena cava; myocardial infarction; arrhythmias; fibrillation; electrocardiograph; electrocardiogram; systole; diastole; cardiac output; stroke volume; cardiac reserve; Frank-Starling law of the heart; tachycardia; bradycardia Important Concepts I. Anatomy of the Heart 1. Size and Location Know the size, weight, and specific location (mediastinum) Compare the base and apex 2. Covering and Layers Know the layers of the pericardium (fibrous, serous) Distinguish between the layers of the serous pericardium (parietal, visceral) Pericardial cavity contains serous fluid; know function of serous fluid Distinguish between the epicardium, myocardium and the endocardium o Myocardium and bundle formation o Significance of the fibrous skeleton 3. Chambers and Great Vessels of Heart Distinguish between the interatrial and interventricular septum Know the following structural parts (coronary sulcus; anterior and posterior interventricular sulcus Distinguish between the atria and ventricles of the heart Know the following about the atria o Features: auricles; pectinate muscles; fossa ovalis o Function of the atria o Role of the Superior and Inferior Vena Cava o Know the three veins from which blood enters the heart from the right side (vena cava and coronary sinus) o Know the blood vessels that returns blood to the left side of the heart (pulmonary veins) Know the following about the ventricles o Know the function of the ventricles o Know the internal features: trabeculae carnea and papillary muscles o Know that the right ventricle contracts and sends blood to the pulmonary arteries(pulmonary trunk)relate to the pulmonary circuit; Left ventricle pumps blood into the aorta which sends blood to all parts of the body (except for the lungs) 4. Circulation Distinguish between the pulmonary and systemic circulation pathways 5. Coronary Circulation Left Coronary artery o Major branches: anterior interventricular artery (left descending) and Circumflex artery Left Descending: Supplies blood to the interventricular sulcus and septum, and anterior ventricular walls; Circumflex supplies blood to left atrium and posterior wall of left ventricle Right Coronary artery o Divides into marginal artery (serves myocardium of lateral right side) and posterior interventricular artery (supplies posterior ventricular walls) Veins-Venous Circulation o Know the location and functions of the following: cardiac veins, coronary sinus; great, middle and small cardiac veins; anterior cardiac veins 6. Valves Know the locations, features and functions of the following valves o Atrioventricular Valves Distinguish between the tricuspid and mitral valve Know the function of the chordae tendineae Know how the valves open and close during the beating of the heart o Semilunar Valves Know how these valves open and close during the beating of the heart 7. 8. 9. II. Microscopic Anatomy Histology of Cardiac muscle tissue o Striated, intercalated discs and gap junctions; functional syncytium o High mitochondria content Contraction of Heart Tissue Self-excitable or autorhythmic cells Contraction as a ‘unit’ Longer absolute refractory periods than skeletal muscle Know the following: o Minor differences between skeletal and cardiac depolarization except for how SR is stimulated to release calcium to cause a contraction o Greater concentration of mitochondria – more oxygen requirements; relies on aerobic respiration Heart Conditions and Disorders Know the causes, characteristics and effects of the following conditions: Pericarditis; Angina pectoris; Stenosis Physiology of the Heart 1. Intrinsic Conduction System – Know the following Know the function of the intrinsic conduction system Know the role of the autorhythmic cells (pacemaker) Know the sequence of excitation (sinoatrial node ---- Atrioventricular node --- Atrioventricular bundle -- bundle branches ---- Purkinje fibers o Know how each is started, time period, location and any specific characteristics 2. Extrinsic Innervation Know the overall function of the extrinsic controls Know the location and function(s) of the cardioacceleratory center and the cardioinhibitory center Distinguish between the parasympathetic and sympathetic fibers and their effects on the beating of the heart 3. Electrocardiography Know how an electrocardiogram is produced Know how to interpret a simple ECG; distinguish between the specific waves o Know what produces the waves and how long they last; what part of the heart they are associated with, etc. 4. Heart Sounds Know how the sounds of the heart are produced 5. Cardiac Cycle Distinguish between systole and diastole Define ‘cardiac cycle’ Know the events associated with each part of the cycle o Ventricular filling; ventricular systole; isovolumetric relaxation 6. Cardiac Output Define ‘cardiac output’ and ‘stroke volume’ ; know the heart rates for both Know the normal blood volume for adults Define ‘cardiac reserve’ Know the following about the regulation of Stroke Volume o Distinguish between EDV and ESV and its relation to stroke volume o How much blood the ventricle pumps out with each beat; 60% of total chamber volume o EDV is major intrinsic factor that influences stroke volume Know the following about Preload and the Frank-Starling Law of the heart o Know the Frank-Starling Law and its effect on stroke volume, stretching of heart fibers, effect on venous return, etc. Know the following about Contractility o Independent of muscle stretch and EDV o Effects of Ca++ on contractility Know the following about Afterload o Define ‘afterload’ o Effect(s) on stroke volume 7. 8. Regulation of Heart Rate Know how the ANS regulates heart rate o Parasympathetic and sympathetic effects Norepinephrine – sympathetic Opposition of the parasympathetic Vagal tone Chemical Regulation o Know the effects of the hormones epinephrine and thyroxine on heart rate o Know how ion imbalances affect heart rate: hypo- and hypercalcemia; hyperkalemia and hypokalemia Disorders- Know the causes, characteristics and effects of the following disorders Tachycardia; Bradycardia Heart Murmurs Arrhythmias and fibrillation Congestive heart failure