ALU 301, CH 7 POSSIBLE QUESTIONS With VERIFIED ANSWERS

What is the purpose of the cardiovascular system? - ANSWER-To meet the oxygen demands of the body and to transport waste products away from tissues for excretion What must exist for the heart to function effectively? - ANSWER-The contraction of the muscle cells must occur at regular intervals and be synchronized. Ventricular contractions must be forceful. Heart valves must be competent and allow one-directional flow of blood. The ventricles must fill adequately during diastole. The conduction system is composed of what type of cells that provide the electrical stimulus necessary to initiate contraction of in a coordinated manner at appropriate intervals. - ANSWER-Pacemaker Cells and myocardial cells Located in the superior and posterior wall of the right atrium and initiates electrical impulse and governs heart rate. This impulse travels through intermodal pathways to the right and left atria to AV node - ANSWER-The sinoatrial, SA- node Located at the AV junction, just above the interventricular septum, the bundle of HIS is delayed allowing Mitral and tricuspid valves to open. The ventricular walls to relax and the atria to contract necessary to maximize blood filling the ventricles. - ANSWER-The Atrioventricular -AV- Node Located in the septum and divides into the right bundle branch and the left bundle branch. Left bundle divides again into the left anterior and posterior fascicles allowing the impulse to be rapidly transmitted throughout the ventricles - ANSWER-The Bundle of HIS A network of conducting strands that lie beneath the ventricular endocardium, responsible for the conduction of impulses to the myocardial cells. - ANSWER-The Purkinje fibers What is the p-wave caused by? - ANSWER-Atrial depolarization The PR Interval - ANSWER-Represents the time required for depolarization of the atria to the onset of depolarization of the ventricles. QRS represents - ANSWER-Ventricular depolarization ST Segment - ANSWER-Indicates that ventricle depolarization is complete and that repolarization is about to begin. Is isoelectric on EKG. QT Interval - ANSWER-Total time of ventricular depolarization and repolarization The T Wave on EKG represents : - ANSWER-Ventricular repolarization