NHA EKG Technician Certification Exam Study Guide-Question and Answers-Complete solution guide-A+ Rated

NHA EKG Technician Certification Exam Study Guide-Question and Answers-Complete solution guide-A+ Rated Where is the heart located? in the thoracic cavity, between the lungs, in the mediastinum cavity, above diaphragm, below sternum, in front of the spine Which ventricle has a thicker wall? left ventricle What are the semilunar valves? pulmonary and aortic What are the atrioventricular valves? tricuspid and bicuspid (mitral) What supports the atrioventricular valves to help prevent back flow of blood? chordae tendineae anchored to papillary muscles What is the S1 sound? "lub" and AV valves closing What is the S2 sound? "dub" and semilunar valves closing What is systole? when the ventricles contract and expel blood; between S1 and S2 beats What is diastole? when the ventricles relax and fill will blood; between S2 and the next S1 What is the blood flow through the heart? vena cava, right atrium, tricuspid valve, right ventricle, pulmonic valve, pulmonary artery, lungs, pulmonary veins, left atrium, bicuspid (mitral) valve, left ventricle, aortic valve, aorta, arteries, arterioles, capillaries, venules, veins What is the epicardium? the outermost layer of the heart where coronary arteries run along; visceral layer of pericardium What is the myocardium? the middle, thick, muscular layer of the heart that does the contracting; this is damaged during an MI What is the endocardium? the innermost layer of the heart that lines the heart chambers, folds back on itself to form heart valves, and is watertight to prevent leakage; the cardiac conduction system is here What is the pericardium? the double-walled sac that encloses the heart with two layers, the visceral layer and the parietal layer; it supports, protects, and anchors the heart to the diaphragm and great vessels and a small amount of pericardial fluid is between the layers to decrease friction What is the superior vena cava? a large vein that returns deoxygenated blood to the right atrium from the head, neck, upper chest, and arms What is the inferior vena cava? a large vein the returns deoxygenated blood to the right atrium from the lower chest, abdomen, and legs What is the aorta? the largest artery in the body that takes oxygenated blood from the left ventricle to systemic circulation to feed all organs of the body What are the five great vessels? superior vena cava, inferior vena cava, pulmonary artery, pulmonary veins, aorta What are the phases of diastole? 1. Rapid filling: atria is full of blood and high pressure, ventricles have just emptied and low pressure, pressure difference causes AV valves to open and flow from atria to ventricles; steady stream 2. Diastasis: the pressure in the atria and ventricles equalizes as blood flows to the ventricles; blood flow slows 3. Atrial Kick: the last phase, atria empty and contract to squeeze all blood out, high pressure in ventricles and low pressure in atria, AV valves pushed up and slam shut; S1 heard at this phase, provides 15-30% of ventricular filling, heart rhythm abnormalities in this phase result in decreased cardiac output What are the phases of systole? 1. Isovolumetric contraction: ventricles full, but not full enough to open semilunar valves, muscle contracts inward to increase pressure, no blood flow and valves are still closed; greatest consumption of myocardial oxygen 2. Ventricular ejection: semilunar valves open, blood pours out of ventricles to aorta and pulmonary artery, half of the blood empties fast, then blood flow slows 3. Protodiastole: blood flow slows as pressure in ventricles, aorta, and pulmonary artery equalizes 4. Isovolumetric relaxation: ventricles relax and pressure is low, aorta and pulmonary artery have high pressures, so semilunar valves slam shut; S2 sound heard at this phase What are the two kinds of heart cells? contractile cells and conduction system cells What part of the nervous system controls the heart?