Ch 19A_ Anatomy of the Heart PDF

Two Circuits takes to 1 min about Pump RBC Heart is transport system – 2 side by side pumps – Right side – receives deoxygenated blood from ↑ low the tissues and pumps it jeviger to the lungs via the pulmonary circuit – Left side – receives oxygenated blood from the lungs and pumps it to e nighe the...

Two Circuits takes to 1 min about Pump RBC Heart is transport system – 2 side by side pumps – Right side – receives deoxygenated blood from ↑ low the tissues and pumps it jeviger to the lungs via the pulmonary circuit – Left side – receives oxygenated blood from the lungs and pumps it to e nighe the tissues via the systemic circuit ↑ lungs ↑ Tissues deoxygenated Oxygenated Heart Roughly fist sized Located in the mediastinum – Between 2nd rib & 5th intercostal space – Apex sits on the diaphragm – 2/3 of mass is left of center – Anterior to vertebral column – Posterior to the sternum Pericardium Double walled serous membrane – pericardium – Fibrous layer – most superficial, tough, anchoring – Parietal layer of serous layer – Visceral layer of serous layer Continuous with outermost layer of the heart wall – epicardium – Pericardial cavity – filled with serous fluid Heart Wall Three layers of the heart wall – Epicardium – continuous with visceral pericardium – Myocardium – cardiac muscle, variable thickness – Endocardium – continuous with endothelial lining of vessels Cardiac Skeleton Dense network of connective tissue – Support – Anchor – Insulation Heart Chambers Four chambers – Two atria – receiving chambers Right atrium receives blood from superior & inferior vena cava & coronary sinus Left atrium receives blood from the pulmonary veins Thin walled, pectinate muscles Seen anteriorly as auricles Separated by interatrial septum – Two ventricles – pumps Thicker walls Separated by thick interventricular septum Walls contain trabeculae carneae & papillary muscles Right ventricle pumps into the pulmonary trunk Left ventricle pumps into the aorta Heart Chambers Blood Flow Through the Heart Heart Valves Four valves – open & close due solely to pressure changes – Two atrioventricular valves Located at the atrioventricular junction Right – tricuspid; left – bicuspid (mitral) Attached to chordae tendineae – Two semilunar valves Found at the base of the large arteries coming from the base of the heart Right – pulmonary; left – aortic Atrioventricular Valves Semilunar Valves Coronary Circulation Supplies the heart with functional blood Right and left coronary arteries branch from the aorta – Right coronary artery Anterior – marginal artery Posterior – posterior interventricular artery – Left coronary artery Anterior – anterior interventricular artery Around – circumflex artery Posterior – marginal – Venous supply Anterior – great cardiac vein Posterior – coronary sinus