1 All of the following are true regarding a normal cardiac cycle exceptA) the ventricles receive 70% of the blood from the atria passively during ventricular diastole B) the aortic valve closes when left ventricular pressure falls below aortic pressure C) there is a point where the atrioventricular and semilunar valves are open at the same time D) the atria and ventricles are both in diastole for a brief period of the cardiac cycle 2 The two major heart sounds are a result ofA) blood entering the atria in large volumes B) closing of heart valves C) contraction of the myocardium D) changes in the blood flow rate through the chambers of the heart 3 A mass of merging cells that act as a unit, 2 of which are found in the heart, is calledA) smooth muscle B) a functional syncytium C) the sinoatrial node D) the cardiac conduction system 4 The cells that initiate the stimulus for contraction of the heart muscle are located in theA) sinoatrial node B) atrioventricular node C) Purkinje fibers D) Bundle of His (AV Bundle) 5 Which of the following sequences correctly describes the conduction pathway of cardiac impulses?A) SA node, AV node, Purkinje fibers, AV bundle, Bundle branches B) AV node, Bundle branches, SA node, AV bundle, Purkinje fibers C) AV bundle, Purkinje fibers, Bundle branches, AV node, SA node D) SA node, AV node, AV bundle, Bundle branches, Purkinje fibers 6 The P wave on an ECG representsA) atrial depolarization B) atrial contraction C) atrial repolarization D) impulse transmission at the AV node 7 Ventricular repolarization is represented by theA) PR interval B) S wave C) R wave D) T wave 8 Concentrations of which of the following electrolytes have direct effects on the myocardium?A) calcium and potassium B) potassium and bicarbonate C) calcium and chloride D) sodium and chloride 9 The middle layer of arterial walls is composed ofA) endothelial tissue B) myocardium C) smooth muscle and elastic connective tissue D) fibrous connective tissue 10 The blood vessel that participates directly in the exchange of substances between body cells and the blood is theA) arteriole B) artery C) capillary D) venule 11 The amount of blood that flows into capillaries is regulated byA) constriction and dilation of capillaries B) arterioles C) the amount of extracellular tissue D) precapillary sphincters 12 Deposits of fatty materials on the inside of arterial walls are calledA) scars B) plaques C) stents D) tumors 13 Plasma proteins help retain water in the blood by maintainingA) osmotic pressure B) hydrostatic pressure C) a vacuum D) filtration 14 The middle layer of the walls of veins differs from arteries in thatA) it contains less fibrous connective tissue B) it contains less smooth muscle C) it is thicker in veins D) it contains some striated muscle 15 Systolic pressure is theA) lowest pressure in the arteries when the heart is relaxed B) highest pressure in the arteries, which occurs during contraction of the heart C) pressure that forces fluid out of the capillaries into the tissue D) pressure generated in each atrium during contraction 16 Which of the following will cause blood pressure to increase?A) a decrease in arteriole diameter B) a decrease in stroke volume C) increased parasympathetic activity D) severe bleeding 17 The Frank-Starling law is related to which of the following cardiac structures?A) interventricular septum B) conduction system C) muscle fibers D) heart valves 18 The right and left ___________ veins merge to form the superior vena cava.A) brachiocephalic B) subclavian C) internal carotid D) external carotid 19 Which of the following vessels carries oxygen-rich blood?A) pulmonary arteries B) pulmonary veins C) coronary sinus D) inferior vena cava 20 Which vessel supplies blood to the liver, stomach and spleen?A) inferior mesenteric artery B) renal artery C) superior mesenteric artery D) celiac artery 21 Tissues depend on a functional circulatory system to supply nutrients and oxygen and to remove accumulated wastes.A) True B) False 22 The pericardial cavity contains fluid that reduces the friction produced by the motion of the heart as it contracts.A) True B) False 23 The ventricles are the upper chambers of the heart; the atria are the lower chambers.A) True B) False 24 When the papillary muscles contract, they pull the cusps of the mitral and tricuspid valves down into the ventricles.A) True B) False 25 The wall of the right ventricle is thicker than that of the left ventricle.A) True B) False 26 The skeleton of the heart is composed of dense connective tissue, which provides sites of attachment for heart valves and muscle fibers.A) True B) False 27 Blood is supplied to the myocardium by the coronary arteries, the first branches of the aorta.A) True B) False 28 Most of the blood from the atria enters the ventricles during atrial contraction.A) True B) False 29 The AV node is the pacemaker of the heart under normal conditions.A) True B) False 30 Atrial repolarization is not seen as a separate wave on the ECG.A) True B) False 31 Increasing temperature slows the heart rate.A) True B) False 32 The right and left brachiocephalic arteries supply blood to the head and upper limbs.A) True B) False 33 The superior mesenteric vein drains directly into the inferior vena cava.A) True B) False