29ANATOMY OF CARDIOVASCULAR SYSTEM Anatomy of Cardiovascular System Cavities Serous membrane = Serosa 2 Layers Between them = Serous Cavity containing Serous Fluid Serous fluid is blood filtrate + secretions by 2 layers of membrane Allows movement of organs with reduced friction Types of Serous Membranes * Pleural Cavities Pleural Cavities holds layers together superior surface of diaphragm lateral surface of mediastinum external surface of lungs Mediastinum DIVISIONS Superior Inferior Anterior = ventral parietal pleura Posterior = dorsal parietal pleura Inferior = diaphragmatic pleura The Diaphragm Skeletal Muscle Dome-shaped (relaxed) Flattens (contracts) I: Central tendon Superior View Action of the Diaphragm Contraction during inspiration Air moves into lungs (highlow pressure) Forced contraction (voluntary) Pushes on abdominal organs to move contents out * Openings of Diaphragm 2 = Esophageal Hiatus for Esophagus and Vagus nerve 3 = Foramen in Central Tendon for Inferior Vena Cava 1 2 3 Parts and regions of the thorax Boundaries Superiorlyjugular notch, sternoclavicular joint, superior border of clavicle, acromion, spinous processes of C7 Inferiorlyxiphoid process, costal arch, 12th and 11th ribs, vertebra T12 Regions Landmarks of thorax Jugular notch corresponds with The 2th thoracic vertebra in male, the 3th thoracic vertebra in female Sternal angle corresponds with The lower border of 4th thoracic vertebra The bifurcation of trachea in the adult The beginning of aortic arch which ends posteriorly at the same level The esophagus is crossed by the left main bronchus * Landmarks of thorax Xiphoid processxiphisternal synchondrosis lies opposite the body of the 9th thoracic vertebra Clavicle Thoracic wall Superficial structures * Thoracic wall Deep structures Deep fascia Superficial layer Intercostal space Internal thoracic vessels Descends into thorax 1.2cm lateral to edge of sternum Ends at the sixth costal cartilage by dividing musculophrenic and superior epigastric arteries Parasternal ln. Heart Anatomy Location * Heart Anatomy Figure 18.1 Coverings of the Heart: Anatomy Pericardium – a double-walled sac around the heart composed of: A superficial fibrous pericardium A deep two-layer serous pericardium The parietal layer lines the internal surface of the fibrous pericardium The visceral layer or epicardium lines the surface of the heart They are separated by the fluid-filled pericardial cavity * Coverings of the Heart: Physiology The pericardium: Prevents overfilling of the heart with blood * Pericardial Layers of the Heart Figure 18.2 Heart Wall Myocardium – cardiac muscle layer forming the bulk of the heart Fibrous skeleton of the heart – crisscrossing, interlacing layer of connective tissue Endocardium – endothelial layer of the inner myocardial surface * Vessels returning blood to the heart include: Superior and inferior venae cavae Right and left pulmonary veins Vessels conveying blood away from the heart include: Pulmonary trunk, which splits into right and left pulmonary arteries Ascending aorta (three branches) – brachiocephalic, left common carotid, and subclavian arteries External Heart: Major Vessels of the Heart (Anterior View) * * External Heart: Anterior View Vessels returning blood to the heart include: Right and left pulmonary veins Superior and inferior venae cavae Vessels conveying blood away from the heart include: Aorta External Heart: Major Vessels of the Heart (Posterior View) * Arteries – right coronary artery (in atrioventricular groove) and the posterior interventricular artery (in interventricular groove) Veins – great cardiac vein, posterior vein to left ventricle, coronary sinus, and middle cardiac vein External Heart: Vessels that Supply/Drain the Heart (Posterior View) * External Heart: Posterior View Gross Anatomy of Heart: Frontal Section Figure 18.4e Atria of the Heart Each atrium has a protruding auricle Pectinate muscles mark atrial walls Blood enters right atria from superior and inferior venae cavae and coronary sinus Blood enters left atria from pulmonary veins * Ventricles of the Heart Papillary muscles and trabeculae carneae muscles mark ventricular walls Right ventricle pumps blood into the pulmonary trunk Left ventricle pumps blood into the aorta * Pathway of Blood Through the Heart and Lungs Right atrium tricuspid valve right ventricle Right ventricle pulmonary semilunar valve pulmonary arteries lungs Lungs pulmonary veins left atrium Left atrium bicuspid valve left ventricle Left ventricle aortic semilunar valve aorta Aorta systemic circulation * Pathway of Blood Through the Heart and Lungs Figure 18.5 Coronary Circulation * Coronary Circulation Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings coronary veins coronary sinus right atrium (inferior to opening Coronary Circulation: Arterial Supply Coronary Circulation: Venous Supply Heart Valves Atrioventricular (AV) valves lie between the atria and the ventricles AV valves prevent backflow into the atria when ventricles contract Chordae tendineae anchor AV valves to papillary muscles * Heart Valves Aortic semilunar valve lies between the left ventricle and the aorta Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk Semilunar valves prevent backflow of blood into the ventricles * Heart Valves Heart Valves Atrioventricular Valve Function Semilunar Valve Function Microscopic Anatomy of Heart Muscle Cardiac muscle is striated, short, fat, branched, and interconnected The connective tissue endomysium acts as both tendon and insertion Intercalated discs anchor cardiac cells together and allow free passage of ions Heart muscle behaves as a functional syncytium InterActive Physiology®: PLAY Vena Cava Receives blood from regions above diaphragm Formed from Rt + Lft Brachiocephalic Veins cranially Azygos Vein empties into it just superior to heart Empties into Right Atrium Formed from Rt + Lft Common Iliac Veins Empties into Right Atrium * Veins of Mediastinum runs superiorly * THANK YOU