Bio 169 Questions and Answers Already Passed

Bio 169 Questions and Answers Already Passed How are papillary muscles situated in the heart? Papillary muscles extend from the inner lining of both ventricles and attach to the valve cusps on both the right and left sides. What role does the right bundle branch play in the heart’s conduction system? The right bundle branch is a split in the heart’s conduction network at the interventricular septum that carries signals from the AV bundle to the right ventricle. What defines atrial tachycardia? Atrial tachycardia is an arrhythmia with a heart rate typically ranging from 150 to 250 beats per minute, caused by rapid ectopic atrial beats or a reentry loop within the AV node. What does an electrocardiogram (ECG) assess? An ECG measures the electrical signals produced by the Purkinje fibers in the heart. 2 What proportion of the body’s weight is made up by the heart, and how much of the body's oxygen does it consume? The heart accounts for 0.5% of the body’s weight and utilizes 5% of the oxygen. Which veins contribute 20% of the venous return in the coronary circulation to the heart? The small coronary veins are responsible for returning 20% of the coronary venous blood to the right ventricle. Which valve prevents the reverse flow of blood from the right ventricle to the right atrium during ventricular contraction? The tricuspid valve prevents backflow into the right atrium during right ventricular systole. What are the specialized muscle structures found in the ventricles called? The ventricles contain trabeculae carnae, which are specialized muscle structures. What fluid is secreted into the pericardial sac by the epicardium and the parietal pericardium? These layers secrete serous fluid into the pericardial sac. 3 What is the sound produced by the closure of the left and right atrioventricular valves? The closure of these valves creates