front 1 Artery is to ________ as vein is to ________. A) efferent; afferent B) afferent; efferent C) toward; away D) afferent; away E) efferent; away | back 1 A) efferent; afferent (afferent arrives, efferent exits) |
front 2 The heart beats approximately ________ times each day. A) 1,000 B) 10,000 C) 100,000 D) 1,000,000 E) 10,000,000 | back 2 C) 100,000 |
front 3 The heart pumps approximately ________ liters of blood each day. A) 8,000 B) 15,000 C) 20,000 D) 50,000 E) 100,000 | back 3 A) 8,000 |
front 4 Excess fluid in the ________ causes cardiac tamponade. A) pericardial cavity B) visceral pericardium C) apex of heart D) left ventricle E) both atria | back 4 A) pericardial cavity (potential space between the parietal and visceral surfaces of the pericardial sac) |
front 5 What is normally found in the pericardial cavity?
| back 5 C. pericardial fluid |
front 6 Which of the following descriptions matches the term near the left fifth intercostal space? A) pericardial cavity B) visceral pericardium C) apex of heart D) aorta E) right atrium | back 6 C) apex of heart |
front 7 The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as A) cardiac tamponade. B) mitral valve prolapse. C) pleural effusion. D) cardiomyopathy. E) pericarditis. | back 7 A) cardiac tamponade |
front 8 The interventricular sulci and coronary sulcus A) contain fat. B) contain arteries. C) contain veins. D) are grooves on the surface of the heart. E) All of the answers are correct. | back 8 E) All of the answers are correct. |
front 9 Blood leaves the right ventricle by passing through the A) aortic valve. B) pulmonary valve. C) mitral valve. D) tricuspid valve. E) bicuspid valve. | back 9 B) pulmonary valve (dirty blood on way to lungs) |
front 10 Intercalated discs serve to transfer ________ from cell to cell. A) ionic currents B) action potentials C) the force of contraction D) electrical signals E) All of the answers are correct. | back 10 E) All of the answers are correct. |
front 11 Why is it important for impulses from the atria to be delayed at the AV node before they pass into the ventricles?
| back 11 B. So the ventricles can finish filling |
front 12 The coronary sulcus is a groove that A) marks the border between the atria and ventricles. B) marks the boundary line between the right and left ventricles. C) marks the boundary line between the right and left atria. D) separates the atrioventricular valves from the atria. E) separates the coronary arteries from the coronary veins. | back 12 A) marks the border between the atria and ventricles (the big sulcus) |
front 13 In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the A) pleural space. B) pericardial space. C) mediastinum. D) cardiac notch. E) ventral cavity. | back 13 C) mediastinum. |
front 14 Contractions of the papillary muscles A) close the atrioventricular valves. B) close the semilunar valves. C) eject blood from the ventricles. D) prevent the atrioventricular valves from reversing into the atria. E) eject blood from the atria into the ventricles. | back 14 D) prevent the atrioventricular valves from reversing into the atria (the chordae tendineae fibers originate at the papillary muscles) |
front 15 The visceral pericardium is the same as the A) mediastinum. B) parietal pericardium. C) epicardium. D) myocardium. E) endocardium. | back 15 C) epicardium. |
front 16 The right atrium receives blood from the A) coronary sinus. B) superior vena cava. C) inferior vena cava. D) systemic circuit. E) All of the answers are correct. | back 16 E) All of the answers are correct. |
front 17 When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n) A) coronary spasm. B) myocardial infarction. C) coronary thrombosis. D) angina pectoris. E) pulmonary embolism. | back 17 C) coronary thrombosis (clotting) |
front 18 When the left ventricle contracts, the distance from the apex to the base A) increases. B) decreases. C) remains unchanged. | back 18 B) decreases. |
front 19 When the left ventricle contracts, the diameter of the ventricular chamber A) increases. B) decreases. C) remains the same. | back 19 decreases |
front 20 Cardiac cells damaged by infarction will show which of the following? A) switch to anaerobic metabolism B) release of enzymes into the circulation C) release of troponin T and I into the circulation D) release of CK-MB into the circulation E) All of the answers are correct. | back 20 E) All of the answers are correct. |
front 21 Blood flowing into the heart from the venae cavae flows next through the ________ valve. A) mitral B) bicuspid C) tricuspid D) pulmonary semilunar E) aortic semilunar | back 21 C) tricuspid (found between the right atrium and the right vetnricle |
front 22 As blood leaves the right ventricle, it passes through the ________ and then into the pulmonary trunk. A) pulmonary veins B) conus arteriosus C) aorta D) inferior vena cava E) superior vena cava | back 22 B) conus arteriosus (where the right ventricle tapers before the pulmonary valve) |
front 23 Coronary veins empty into the A) left atrium. B) left ventricle. C) right atrium. D) right ventricle. E) conus arteriosus. | back 23 C) right atrium (these are the veins bringing dirty blood back from the heart walls to the coronary sulcus) |
front 24 There are ________ pulmonary veins. A) 2 B) 4 C) 6 D) 8 E) 12 | back 24 B) 4 (2 left and 2 right pulmonary veins) |
front 25 Rupture of the papillary muscles in the left ventricle may result in A) mitral regurgitation. B) mitral valve prolapse. C) bicuspid regurgitation. D) bicuspid prolapse. E) All of the answers are correct. | back 25 E) All of the answers are correct (mitral and bicuspid are the same thing; regurgitation is backflow; prolapse is when valves don't close properly and are pushed back into the atria) |
front 26 When the semilunar valves close, the AV valves then A) close. B) open. C) make the third heart sound. D) contract. E) prolapse. | back 26 B) open. |
front 27 The ________ deliver(s) blood to the myocardium. A) coronary arteries B) cardiac veins C) superior vena cava D) carotid arteries E) coronary sinus | back 27 A) coronary arteries (in systemic circuit arteries have clean blood moving away from heart, veins have dirty blood moving towards the heart) |
front 28 The connective tissue fibers of the myocardium A) add strength and prevent overexpansion of the heart. B) help distribute the forces of contraction. C) provide elasticity to help return the heart to its normal size. D) provide physical support for cardiac muscle. E) All of the answers are correct. | back 28 E) All of the answers are correct (myocardium is muscular tissue of the heart) |
front 29 Blood is supplied to the muscular wall of the left atrium by the A) brachiocephalic artery. B) right coronary artery. C) left coronary artery. D) phrenic arteries. E) pulmonary arteries. | back 29 C) left coronary artery (supplies blood to the left ventricle, left atrium, and interventricular septum) |
front 30 The pulmonary semilunar valve prevents backward flow into the A) aorta. B) pulmonary trunk. C) pulmonary veins. D) right ventricle. E) left atrium. | back 30 D) right ventricle (in between the right ventricle and the pulmonary trunk) |
front 31 The bicuspid or mitral valve is located A) in the opening of the aorta. B) in the opening of the pulmonary trunk. C) where the venae cavae join the right atrium. D) between the right atrium and right ventricle. E) between the left atrium and left ventricle. | back 31 E) between the left atrium and left ventricle. |
front 32 The ________ valve prevents backward flow into the left atrium. A) semicaval B) semilunar C) bicuspid D) tricuspid E) pulmonic | back 32 C) bicuspid (left atrioventricular valve) |
front 33 The function of an atrium is to A) collect blood. B) pump blood to the lungs. C) pump blood into the systemic circuit. D) pump blood to the ventricle. E) collect blood then pump it to the ventricle. | back 33 E) collect blood then pump it to the ventricle. |
front 34 Compared to the right ventricle, the left ventricle has all the following characteristics except A) has a thicker wall. B) is round in cross section. C) pumps a greater volume. D) works harder. E) produces about four to six times more pressure when it contracts. | back 34 C) pumps a greater volume (ventricles hold and pump equal amounts of blood) |
front 35 Which of the following are involved in the pulmonary circuit? A) superior vena cava, right atrium, left ventricle B) right ventricle, pulmonary veins, aorta C) right ventricle, pulmonary trunk, left atrium D) inferior vena cava, right atrium, aorta E) left ventricle, pulmonary veins, right atrium | back 35 C) right ventricle, pulmonary trunk, left atrium |
front 36 The right pulmonary veins carry ________ blood to the ________. A) deoxygenated; left atrium B) oxygenated; right lung C) deoxygenated; superior vena cava D) deoxygenated; right atrium E) oxygenated; left atrium | back 36 E) oxygenated; left atrium |
front 37 The following is a list of vessels and structures that are associated with the heart. What is the correct order for the flow of blood entering from the systemic circulation?
A) 1, 2, 7, 8, 3, 4, 6, 5 B) 1, 7, 3, 8, 2, 4, 6, 5 C) 5, 1, 3, 7, 8, 2, 4, 6 D) 5, 3, 1, 7, 8, 4, 2, 6 E) 5, 1, 3, 8, 7, 2, 4, 6 | back 37 C) 5, 1, 3, 7, 8, 2, 4, 6 |
front 38 The pulmonary arteries carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver. | back 38 B) lungs. |
front 39 The pulmonary veins carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver. | back 39 A) heart. |
front 40 The foramen ovale in the fetal heart is located in the A) right atrium. B) left atrium. C) right ventricle. D) left ventricle. E) interatrial septum. | back 40 E) interatrial septum (because the foramen ovale connected the 2 atrium in the fetus, therefore has to be in the septum not the atrium) |
front 41 Blood is supplied to the myocardium by A) the coronary sinus. B) contact with blood in the pumping chambers. C) the coronary arteries. D) arteries that branch from the pulmonary arteries. E) arteries that branch off the subclavian arteries. | back 41 C) the coronary arteries (to feed to heart walls oxygenated blood) |
front 42 The first blood vessels to branch from the aorta are the ________ arteries. A) pulmonary B) coronary C) circumflex D) carotid E) subclavian | back 42 B) coronary (feeds itself first) |
front 43 The marginal branch and posterior interventricular branch are branches of the A) right coronary artery. B) left coronary artery. C) circumflex artery. D) coronary sinus. E) aorta. | back 43 A) right coronary artery. |
front 44 The circumflex branch and the anterior interventricular artery are branches of the A) right coronary artery. B) left coronary artery. C) interventricular artery. D) coronary sinus. E) aorta. | back 44 B) left coronary artery. |
front 45 The great and middle cardiac veins drain blood into the A) superior vena cava. B) inferior vena cava. C) coronary sinus. D) coronary sulcus. E) aorta. | back 45 C) coronary sinus. |
front 46 In cardiac muscle, the fast depolarization phase of the action potential is the result of A) increased membrane permeability to sodium ions. B) increased membrane permeability to potassium ions. C) decreased membrane permeability to calcium ions. D) decreased membrane permeability to sodium ions. E) increased membrane permeability to chloride ions. | back 46 A) increased membrane permeability to sodium ions. |
front 47 The long plateau phase of the cardiac muscle action potential is due to A) movement of fewer sodium ions across the cell membrane. B) calcium channels remaining open. C) increased membrane permeability to potassium ion. D) decrease in the amount of calcium diffusing across the membrane. E) increased membrane permeability to sodium ions. | back 47 B) calcium channels remaining open (calcium coming in) |
front 48 In cardiac muscle A) calcium ions are not released from the sarcoplasmic reticulum. B) calcium ions do not bind to troponin molecules. C) calcium ions play no role in the process of contraction. D) about 20 percent of the calcium ion required for contraction comes from outside the cell. E) calcium ions play an important role in repolarizing the membrane after the depolarization phase. | back 48 D) about 20 percent of the calcium ion required for contraction comes from outside the cell. |
front 49 The normal pacemaker of the heart is located in A) the Purkinje fibers. B) the sinoatrial node. C) the atrioventricular node. D) the wall of the left ventricle. E) both the left and right ventricles. | back 49 B) the sinoatrial node. |
front 50 Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing. A) P wave B) T wave C) QRS complex D) P-R interval E) R-T interval | back 50 C) QRS complex |
front 51 As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit A) tonus. B) treppe. C) tetany. D) recruitment. E) fatigue. | back 51 C) tetany (tetany is spasms or cramps; refractory period is time it takes for muscle to respond to second stimulus/action potential) |
front 52 If the pacemaker cells in the SA node become more permeable to potassium ions, the A) heart rate will increase. B) heart rate will decrease. C) cells will depolarize. D) cells will hyperpolarize. E) heart rate will decrease and cells will hyperpolarize. | back 52 D) cells will hyperpolarize (K+/potassium causes hyperpolarization) |
front 53 If the connection between the SA node and AV node becomes blocked, A) the ventricles will beat faster. B) the ventricles will beat more slowly. C) the ventricular beat will remain unchanged. D) cardiac output will increase. E) the atria will contract more forcefully. | back 53 B) the ventricles will beat more slowly (electrical cannot get through to stimulate the ventricles to contract) |
front 54 The following are structural components of the conducting system of the heart.
The sequence in which excitation would move through this system is A) 1, 4, 3, 2, 5. B) 3, 2, 4, 5, 1. C) 3, 5, 4, 2, 1. D) 4, 3, 2, 5, 1. E) 4, 2, 3, 5, 1. | back 54 D) 4, 3, 2, 5, 1. |
front 55 The P wave of the electrocardiogram is a signal from A) the SA node. B) depolarization of the AV node. C) depolarization of the atria. D) repolarization of the atria. E) depolarization of the ventricles. | back 55 C) depolarization of the atria. |
front 56 If there is a complete block between the SA node and the AV node, how would the ECG be affected? A) The P-R interval will be shorter. B) The QRS duration will be longer. C) There will be much bigger P waves. D) The ventricles will stop beating. E) The rate of P waves will be faster than the rate of QRS complexes. | back 56 E) The rate of P waves will be faster than the rate of QRS complexes. |
front 57 Depolarization of the ventricles is represented on an electrocardiogram by the A) P wave. B) T wave. C) S wave. D) QRS complex. E) PR complex. | back 57 D) QRS complex. |
front 58 The T wave on an ECG tracing represents A) atrial depolarization. B) atrial repolarization. C) ventricular depolarization. D) ventricular repolarization. E) ventricular contraction. | back 58 D) ventricular repolarization. |
front 59 Analysis of the electrocardiogram can reveal all of the following except A) heart rate. B) stroke volume. C) the condition of the conducting system. D) the effects of drugs and poisons. E) the duration of the ventricular action potential. | back 59 B) stroke volume (amount of blood ejected from the ventricles) |
front 60 During the T wave of the electrocardiogram, the ventricles are A) depolarizing. B) repolarizing. C) contracting. D) relaxing. E) both repolarizing and relaxing. | back 60 E) both repolarizing and relaxing. |
front 61 Pacemaker cells in the SA node A) have a well-defined resting potential. B) can spontaneously depolarize. C) also contract with the rest of the cells in the heart wall. D) are special neurons that convey signals from the brain to the heart. E) All of the answers are correct. | back 61 B) can spontaneously depolarize. |
front 62 Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute. A) 20-40 B) 40-60 C) 80-100 D) 100-140 E) 140-180 | back 62 C) 80-100 |
front 63 Depolarization of the atria corresponds to the EKG's A) P wave. B) QRS complex. C) QT interval. D) T wave. E) S-T segment. | back 63 A) P wave. |
front 64 The first heart sound is heard when the A) AV valves open. B) AV valves close. C) semilunar valves close. D) atria contract. E) blood enters the aorta. | back 64 B) AV valves close ("lubb" when mitral and tricuspid valves close) |
front 65 The first heart sound ("lubb") is associated with A) atrial systole. B) closing of the atrioventricular valves. C) opening of the atrioventricular valves. D) closing of the semilunar valves. E) opening of the semilunar valves. | back 65 B) closing of the atrioventricular valves (tricuspid/mitral valves) |
front 66 Considering the left ventricle, why does isovolumetric ventricular contraction occur during ventricular systole? A) The ventricle needs to pressurize the blood to close the aortic valve. B) Ventricular pressure is greater than atrial pressure so the ventricle cannot eject blood. C) The bicuspid valve needs time to shut before the ventricle can eject blood. D) Aortic pressure is higher than ventricular pressure and the ventricle must pressurize the blood to open the aortic valve. E) The ventricle is still filling with blood and therefore cannot eject blood during this time. | back 66 D) Aortic pressure is higher than ventricular pressure and the ventricle must pressurize the blood to open the aortic valve (even though the ventricles contract they do not eject blood; all valves closed; pressure in pulmonary trunk and atria is still greater) |
front 67 The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the A) atrial systole. B) early diastolic filling phase. C) late diastolic filling phase. D) systolic ejection phase. E) dicrotic phase. | back 67 D) systolic ejection phase. |
front 68 A heart murmur might be caused by A) aortic valve insufficiency. B) mitral valve insufficiency. C) pulmonic valve insufficiency. D) swirling of blood in the ventricle. E) All of the answers are correct. | back 68 E) All of the answers are correct. |
front 69 At a heart rate of 60 beats/minute, a cardiac cycle lasts A) 60 seconds. B) 60 milliseconds. C) 1 second. D) 370 milliseconds. E) 630 milliseconds. | back 69 C) 1 second. |
front 70 During ventricular systole, the A) atria are contracting. B) blood is entering the ventricles. C) AV valves are closed. D) pressure in the ventricles remains constant. E) pressure in the aorta remains constant. | back 70 C) AV valves are closed. |
front 71 With each ventricular systole, A) blood pressure remains steady. B) the ventricles fill with blood. C) blood pressure decreases. D) cardiac output decreases. E) blood pressure increases. | back 71 E) blood pressure increases. |
front 72 An increase in the rate of action potentials from baroreceptors will trigger a reflex to A) increase heart rate. B) decrease heart rate. C) decrease blood pressure. D) both decrease heart rate and decrease pressure. E) both increase heart rate and increase pressure. | back 72 D) both decrease heart rate and decrease pressure. |
front 73 The volume of blood ejected from each ventricle during a contraction is called the A) end-diastolic volume. B) end-systolic volume. C) stroke volume. D) cardiac output. E) cardiac reserve. | back 73 C) stroke volume. |
front 74 Each of the following factors will increase cardiac output except increased A) venous return. B) parasympathetic stimulation. C) sympathetic stimulation. D) heart rate. E) force of contraction. | back 74 B) parasympathetic stimulation. |
front 75 "An increase in end-diastolic volume increases the stroke volume" is a way of stating ________ law of the heart. A) Robin's B) Finch's C) Starling's D) Sparrow's E) Hawking's | back 75 C) Starling's |
front 76 Which of the following would increase heart rate? A) increased sympathetic stimulation of SA node B) decreased parasympathetic stimulation of nodal fibers C) increased levels of epinephrine D) faster depolarization of the pacemaker potential E) All of the answers are correct. | back 76 E) All of the answers are correct. |
front 77 The heart is innervated by ________ nerves. A) parasympathetic B) sympathetic C) both parasympathetic and sympathetic D) neither parasympathetic nor sympathetic E) somatomotor | back 77 C) both parasympathetic and sympathetic (in the cardiac plexus) |
front 78 Stroke volume depends on A) end diastolic volume. B) the contractility of the ventricle. C) the pressure required to pump blood into the aorta. D) venous return of blood to the heart. E) All of the answers are correct. | back 78 E) All of the answers are correct. |
front 79 Cardiac output can be increased by all of the following except A) decreasing ejection fraction. B) decreasing end systolic volume. C) increasing stroke volume. D) increasing ejection fraction. E) increasing heart rate. | back 79 A) decreasing ejection fraction. |
front 80 Drugs known as calcium channel blockers such as nifedipine can be used to A) decrease the force of cardiac contraction. B) decrease blood pressure. C) dilate the coronary arteries. D) produce a negative inotropic effect. E) All of the answers are correct. | back 80 E) All of the answers are correct. |
front 81 Heart rate is controlled by neurons of the cardiovascular center located in the A) pons. B) thalamus. C) medulla oblongata. D) hypothalamus. E) higher centers. | back 81 medulla oblongata. |
front 82 The cardioacceleratory center activates sympathetic neurons and the cardioinhibitory center controls parasympathetic neurons. A) The first part of the statement is true but the second part is false. B) The first part of the statement is false but the second part is true. C) Both parts of the statement are true. D) Both parts of the statement are false. E) The first part is always true, but the second part is sometimes true. | back 82 C) Both parts of the statement are true. |
front 83 Which of the following is true about the atrial reflex? A) also called Bainbridge reflex B) triggered by atrial stretch receptors C) triggered by increasing venous return D) depends on sympathetic innervation E) All of the answers are correct. | back 83 E) All of the answers are correct. |
front 84 Which of the following would cause stroke volume to increase? A) when venous return is decreased B) when ventricular contraction is reduced C) when diastolic blood pressure is decreased D) decrease in heart rate E) All of the answers are correct. | back 84 C) when diastolic blood pressure is decreased |
front 85 Cardiac output is increased by A) sympathetic stimulation. B) increased end systolic volume. C) decreased end diastolic volume. D) decreased venous return. E) inhibiting the atrial reflex. | back 85 A) sympathetic stimulation. |
front 86 Activation of which kind of receptor causes heart rate to increase? A) alpha-one B) beta-one C) muscarinic D) beta-two E) preganglionic | back 86 B) beta-one |
front 87 Drugs that block the beta-one adrenergic receptors will A) increase heart rate. B) decrease heart rate. C) increase contractility. D) increase cardiac output. E) decrease the end-systolic volume. | back 87 B) decrease heart rate. |
front 88 If the force of ventricular contraction increases, what will happen to the end-systolic volume? A) increase B) fluctuate rapidly C) remain the same D) decrease E) reduced to zero | back 88 D) decrease (ventricle won't have chance to fill as much) |
front 89 End-systolic volume is defined as the A) amount of blood a ventricle ejects per cycle. B) amount of blood which backflows into a ventricle. C) amount of blood remaining in an atrium after atrial systole. D) amount of blood remaining in a ventricle after contraction. E) stroke volume multiplied by the heart rate. | back 89 D) amount of blood remaining in a ventricle after contraction. |
front 90 A patient has an end-diastolic volume of 125 ml. A heart attack has weakened her left ventricle so it can pump a stroke volume of only 40 ml. Calculate her end-systolic volume. A) 85 ml B) 3.1 ml C) 5000 ml D) 165 ml E) There is not enough data given to calculate the end-systolic volume. | back 90 A) 85 ml (SV = EDV - ESV or 40 = 125 - x) |
front 91 Calculate cardiac output if the heart rate is 125 beats/minute, the end-diastolic volume is 130 ml, and the end-systolic volume is 40 ml. A) 21,250 ml / min B) 16,250 ml / min C) 11,250 ml / min D) 195 ml / min E) 200 ml / min | back 91 C) 11,250 ml / min (CO = HR x SV or 125 x 90 = 11250) |
front 92 Calculate the cardiac output of a patient with a heart rate of 100 beats/minute and a stroke volume of 75 ml. A) 0.75 ml / min B) 750 ml / min C) 7500 ml / min D) 175 ml / min E) 25 ml / min | back 92 C) 7500 ml / min (CO = HR x SV) |
front 93 The heart lies within the ________ cavity. A) peritoneal B) pleural C) orbital D) dorsal E) pericardial | back 93 E) pericardial |
front 94 The superior portion of the heart where major blood vessels enter and exit is the A) apex. B) hilum. C) base. D) septum. E) mediastinum. | back 94 C) base. |
front 95 The inferior point of the heart is called the A) apex. B) hilum. C) base. D) septum. E) mediastinum. | back 95 A) apex. |
front 96 Most of the mass of the heart lies A) left of midline. B) right of midline. C) on the sagittal plane. D) inferior to the midline. E) on the midline of the body. | back 96 A) left of midline. |
front 97 The wall of the ________ rests on the diaphragm. A) left atrium B) right ventricle C) left ventricle D) right atrium E) aorta | back 97 B) right ventricle |
front 98 The space between the pleural cavities is called the A) mediastinum. B) subcardium. C) endocardium. D) myocardium. E) epicardium. | back 98 A) mediastinum. |
front 99 Pericardial fluid A) provides oxygen to the heart muscle. B) is located between the myocardium and the endocardium. C) is a lubricant between the heart and the pericardial sac. D) consists of plasma that has leaked out of whole blood. E) flows through the four chambers of the heart. | back 99 C) is a lubricant between the heart and the pericardial sac. |
front 100 The ________ is shared by the two ventricles. A) vena cava B) bicuspid valve C) chordate tendinae D) interventricular septum E) trabeculae | back 100 D) interventricular septum |
front 101 Muscular ridges on the inner surface of the ventricles are called A) coronary sinuses. B) trabeculae carneae. C) intercalated discs. D) papillary muscles. E) chordate tendinae. | back 101 B) trabeculae carneae. |
front 102 The ________ circuit carries blood to and from the lungs. A) pulmonary B) systemic C) oxygen D) portal E) body | back 102 A) pulmonary |
front 103 The ________ circuit carries blood from the aorta to the right ventricle. A) pulmonary B) systemic C) oxygen D) portal E) body | back 103 B) systemic |
front 104 The ________ carry blood away from the heart. A) arterioles B) arteries C) veins D) venules E) capillaries | back 104 B) arteries |
front 105 The ________ carry blood toward the heart. A) arterioles B) arteries C) veins D) lacteals E) capillaries | back 105 C) veins |
front 106 The ________ covers the outer surface of the heart. A) epicardium B) myocardium C) endocardium D) parietal pericardium E) mediastinum | back 106 A) epicardium |
front 107 The muscle layer of the heart is the A) epicardium. B) myocardium. C) endocardium. D) parietal pericardium. E) mediastinum. | back 107 B) myocardium. |
front 108 The ________ lines the chambers of the heart, covers the heart valves, and is continuous with the endothelium. A) epicardium B) myocardium C) endocardium D) visceral pericardium E) mediastinum | back 108 C) endocardium |
front 109 Oxygen is added to blood as it flows through the ________ circuit. A) pulmonary B) systemic C) oxygen D) portal E) body | back 109 A) pulmonary |
front 110 The term ________ refers to blockage in the coronary circulation. A) congestive heart failure B) atherosclerosis C) coronary artery disease D) embolism E) phlebitis | back 110 C) coronary artery disease |
front 111 ________ is the symptom generally brought on by coronary ischemia. A) Angina pectoris B) Shortness of breath C) A rash D) Hematuria E) Fluid in the lungs | back 111 A) Angina pectoris (chest pain caused by reduced blood flow to the heart) (ischemia is inadequate blood supply) |
front 112 In a procedure known as ________, an inflatable balloon at the end of a catheter is used to press plaque back against the vessel wall. A) balloon angioplasty B) coronary arterial bypass graft C) intravenous catheterization D) ablation E) atherectomy | back 112 A) balloon angioplasty |
front 113 A procedure in which a length of the patient's vein or artery is used to create a detour around an obstruction in a coronary artery is called A) balloon angioplasty. B) coronary arterial bypass graft. C) intravenous catheterization. D) ablation. E) atherectomy | back 113 B) coronary arterial bypass graft. |
front 114 Which of the following statements is true regarding cardiac muscle? A) Its main source of ATP production is glycogen. B) The actin and myosin myofilaments are not arranged in sarcomeres. C) Cardiac muscle preferentially metabolizes anaerobically. D) There are specialized gap junctions in cardiac muscle not found in skeletal or smooth muscles. E) Cardiac muscle goes into sustained contractions faster than skeletal muscle. | back 114 D) There are specialized gap junctions in cardiac muscle not found in skeletal or smooth muscles. |
front 115 A fine tubular wire mesh called a ________ may be inserted into a coronary vessel, holding it open. A) angioplast B) stent C) angiogram D) keyhole E) catheter | back 115 B) stent |
front 116 The coronary sinus drains the ________ into the ________ A) coronary arteries; left ventricle B) cardiac veins; right atrium C) interventricular artery; left ventricle D) right atrium; right ventricle E) cardiac vein; right ventricle . | back 116 B) cardiac veins; right atrium |
front 117 The ________ is a remnant of an important fetal blood vessel that once linked the pulmonary and systemic circuits. A) fossa ovalis B) ductus arteriosus C) foramen ovale D) ductus venosus E) ligamentum arteriosum | back 117 E) ligamentum arteriosum |
front 118 Which of the following statements is true concerning differences between the right and left ventricles? A) The right ventricle pumps with more force compared to the left. B) The left ventricles pumps twice as much blood as the right ventricle. C) The right ventricles pumps blood to the body, whereas the left ventricle pumps blood to the lungs. D) The right ventricle is conical-shaped while the left ventricle is half-moon shaped. E) The efficiency of the right ventricle is increased by the left ventricle because the wall of the left ventricle pushes into the right ventricle. | back 118 E) The efficiency of the right ventricle is increased by the left ventricle because the wall of the left ventricle pushes into the right ventricle. |
front 119 The two types of cardiac muscle cells involved in a normal heartbeat include specialized cells of the conducting system and ________ cells. A) contractile B) conductive C) intercalated D) pacemaker E) internodal | back 119 A) contractile |
front 120 The property of heart muscle to contract in the absence of neural or hormonal stimulation is called A) intrinsic. B) extrinsic. C) automaticity. D) self-replicating. E) self-starting. | back 120 C) automaticity (or autorhythmicity) |
front 121 Cells that spontaneously make action potentials make up ________ tissue. A) contractile B) conductive C) intercalated D) pacemaker E) internodal | back 121 D) pacemaker |
front 122 The structures responsible for distributing excitation to the contractile cells are A) contractile cells. B) conducting cells. C) intercalated cells. D) pacemaker cells. E) intermodal cells. | back 122 B) conducting cells. |
front 123 The contraction phase of the cardiac cycle is called A) depolarization. B) systole. C) diastole. D) hyperpolarization. E) asystole. | back 123 B) systole. |
front 124 The relaxation phase of the cardiac cycle is called A) depolarization. B) systole. C) diastole. D) hyperpolarization. E) asystole. | back 124 C) diastole. |
front 125 Which event occurs during ventricular systole? A) closing of the bicuspid and tricuspid valves B) closing of the semilunar valves C) the second heart sound D) release of an action potential from the sinoatrial node E) expansion of the ventricles | back 125 A) closing of the bicuspid and tricuspid valves |
front 126 Abnormal heart sounds caused by turbulent flow through faulty valves are called A) ectopic foci. B) murmurs. C) asystole. D) fibrillations. E) flutters. | back 126 B) murmurs. |
front 127 The backward flow of blood from a ventricle to its atrium or from a outflow vessel to its ventricle is called A) emesis. B) flutter. C) fibrillation. D) regurgitation. E) stenosis. | back 127 D) regurgitation. |
front 128 In mitral valve prolapse, the cusps of the mitral valve are pushed into the A) left ventricle. B) right ventricle. C) left atrium. D) right atrium. | back 128 C) left atrium. |
front 129 The ________ is the amount of blood in a ventricle after it has contracted and before it begins to refill. A) ejection fraction B) end-diastole volume C) start-diastolic volume D) end-systolic volume E) stroke volume | back 129 D) end-systolic volume |
front 130 The ________ is the volume of blood in a ventricle at the beginning of systole. A) ejection fraction B) end-diastole volume C) start-diastolic volume D) end-systolic volume E) stroke volume | back 130 B) end-diastole volume |
front 131 The amount of blood remaining in the ventricle when the semilunar valve closes is the A) ejection fraction. B) end-diastole volume. C) start-diastolic volume. D) end-systolic volume. E) stroke volume. | back 131 D) end-systolic volume. |
front 132 ________ is when the heart can't maintain adequate cardiac output. A) Heart failure B) Fibrillation C) Flutter D) Murmur E) Coronary heart disease | back 132 A) Heart failure |
front 133 The ________ is the difference between the resting and maximal cardiac output. A) end-systolic volume B) end-diastolic volume C) cardiac reserve D) stroke volume E) ejection fraction | back 133 C) cardiac reserve |
front 134 The principle that increasing the end-diastolic volume results in a corresponding increase in the stroke volume is known as A) afterload. B) cardiac capacity. C) cardiac reserve. D) Starling's law of the heart. E) expandibility. | back 134 Starling's law of the heart. |
front 135 The amount of blood returning to the heart is the A) afterload. B) stroke volume. C) end-diastolic volume. D) cardiac reserve. E) venous return. | back 135 venous return |
front 136 A doctor tells her nursing students that it is important to monitor patients' blood pressure when they are receiving verapamil (a calcium channel blocker). Why? | back 136 Calcium channel blockers inhibit the movement of calcium ions from the interstitial fluid into cardiac and smooth muscle cells. This would cause a decrease in heart rate, stroke volume, and cardiac output. These in turn would lower blood pressure. In addition, the calcium channel blockers would also inhibit contraction of the smooth muscle in the wall of blood vessels, causing them to get wider and thus also lower blood pressure. Because both heart and smooth muscle cells are inhibited by verapamil, its effects on blood pressure are particularly potent. |
front 137 A patient's ECG recording shows a very long P-R interval. What is the cause of this abnormal wave pattern? | back 137 The P wave marks the time of atrial depolarization and the QRS complex signals ventricular depolarization. Between those two events the AV node was excited and the action potential was spread through the conducting tissue to the ventricular myocardium. A prolonged P-R interval signifies an usually slow conduction through the AV node and conducting system, possibly due to insufficient blood flow (ischemia). |
front 138 If a patient's resting cardiac output is 5.6 l/min and on a stress test she elevated her heart rate to a maximum of 176 beats/min with a stroke volume of 115 ml/beat, what is her cardiac reserve? Show your work. | back 138 Cardiac reserve equals maximum cardiac output - resting cardiac output. Maximum CO = HR × SV = 176 beats/minute × 0.115 liters/beat = 20.2 liters/minute. Cardiac reserve equals 14.6 liters/minute. |
front 139 Which of the following contains the trabeculae carneae?
| back 139 right ventricle |
front 140 Blood flows from the left atrium through the __________ to the left ventricle.
| back 140 mitral valve (also known as left atrioventricular (AV) valve or biscuspid) |
front 141 The left coronary artery supplies blood to __________.
| back 141 the anterior interventricular artery and the circumflex branch |
front 142 Which of the following is NOT a characteristic of cardiac muscle cells?
| back 142 They have multiple nuclei. |
front 143 Which heart chamber has the thickest muscular walls?
| back 143 D) Left ventricle |
front 144 Which vessels have very thin walls and are often called exchange vessels because they allow for the exchange of nutrients, gases, and wastes with surrounding tissues?
| back 144 D. Capillaries |
front 145 What is the function of the chordae tendineae?
| back 145 A. To anchor the AV valve flaps and prevent backflow (regurgitation) of blood into the atria |
front 146 Which valve is found between the right atrium and the right ventricle?
| back 146 A. Tricuspid |
front 147 The passageways between cardiac muscle cells that allow ions to pass freely are called __________.
| back 147 A. Gap junctions |
front 148 The “double pump” function of the heart includes the right side, which serves as the __________ circuit pump, and the left side, which serves as the __________ pump.
| back 148 A. pulmonary; systemic |
front 149 The right and left coronary arteries originate at the base of the __________.
| back 149 A. ascending aorta |
front 150 The blood vessels in the cardiovascular system are subdivided into three circuits known as the __________.
| back 150 A. coronary, pulmonary, and systemic circuits |
front 151 A large vein that opens into the right atrium and brings in venous blood from the heart tissue is the __________.
| back 151 A. coronary sinus |
front 152 Valvular heart disease can be a result of __________.
| back 152 A. congenital malformation, carditis, rheumatic fever |
front 153 When deoxygenated blood leaves the right ventricle through a semilunar valve, it is forced into the __________.
| back 153 A. pulmonary arteries |
front 154 The left atrium receives blood from the pulmonary circuit and empties it into the __________.
| back 154 C. left ventricle |
front 155 The plateau of the action potential in cardiac muscle cells is due to __________.
| back 155 A. Calcium (Ca2) entry into the cells |
front 156 Which of the following occurs during the first phase of ventricular systole?
| back 156 D. The AV valves close, and ventricular pressure rises. |
front 157 What is happening during isovolumetric contraction?
| back 157 A. No blood is being ejected from the ventricles |
front 158 When do the semilunar valves close?
| back 158 C. When the pressure in the arteries is greater than the pressure in the ventricles |
front 159 During ventricular systole, the blood volume in the atria is __________, and the volume in the ventricle is __________.
| back 159 B. increasing; decreasing |
front 160 If cells of the SA node did NOT function, what would happen to the heart?
| back 160 A. The heart would beat more slowly |
front 161 What has its own intrinsic conduction system to set the pace of the beating heart? | back 161 Cardiac muscle tissue |
front 162 Decreased parasympathetic (vagus) stimulation to the heart results in a situation known as __________.
| back 162 A. tachycardia (fast) |
front 163 Which of the following are characteristics of cardiac muscle cells?
| back 163 A. Striated, single central nucleus, and involuntary |
front 164 When a chamber of the heart fills with blood and prepares for the start of the next cardiac cycle, the chamber is in __________.
| back 164 C. diastole |
front 165 How do the SA node cells cause autorhythmicity?
| back 165 A. They have a slow inflow of Na+ (sodium) after repolarization. |
front 166 What is the name of the volume of blood in the ventricles immediately before they contract?
| back 166 B. End-diastolic volume |
front 167 Why is it important for impulses from the atria to be delayed at the AV node before they pass into the ventricles?
| back 167 B. So the ventricles can finish filling |
front 168 What structures in the conduction system conduct impulses very rapidly to the ventricular myocardium?
| back 168 A. Purkinje fibers |
front 169 The QRS complex of the ECG appears as the __________.
| back 169 C. ventricles depolarize |
front 170 The first sound of the heart occurs as a result of __________.
| back 170 A. QRS complex |
front 171 Which of the following events does NOT occur because of the QRS wave?
| back 171 D. The AV valve opens |
front 172 What ion movement is responsible for the rapid depolarization phase of the ventricular muscle cell action potential?
| back 172 A. Na+ (sodium) inflow |
front 173 Physicians are interested in cardiac output because it provides a useful indication of __________.
| back 173 B. ventricular efficiency over time |
front 174 What part of the brain controls cardiac function?
| back 174 A. medulla oblongata |
front 175 What is happening during the atrial reflex?
| back 175 C. The heart rate increases |
front 176 Parasympathetic stimulation from the vagus nerve results in __________.
| back 176 D. a decrease in heart rate |
front 177 What is the potential problem if the heart beats too rapidly?
| back 177 A. filling time decreases |
front 178 How should you define cardiac output?
| back 178 B. The amount of blood pumped out of the left ventricle in one minute |
front 179 Which statement is NOT a component of the Frank-Starling Principle?
| back 179 D. Slowing the heart rate decreases stroke volume |
front 180 Which of the following could increase the strength of the contraction of a ventricle?
| back 180 A. increased stretch on the ventricle |
front 181 Cardiac reflexes that adjust cardiac function are triggered by sensory input to the cardiac centers. Which sensory information is NOT something that triggers these reflexes?
| back 181 B. Heart rate |
front 182 Which of the following statements about autonomic tone is FALSE?
| back 182 C. Sympathetic effects dominate in a resting healthy adult. |
front 183 How does sympathetic stimulation increase the heart rate?
| back 183 D. Increasing Na+ and Ca2+ inflow into SA nodes cells |
front 184 What is ejection fraction?
| back 184 B. The percentage of end-diastolic volume represented by the stroke volume |
front 185 Which of the following is an effect of norepinephrine on the heart?
| back 185 A. All of the listed statements are correct. |
front 186 The amount of blood pumped out of each ventricle during a single beat is the __________.
| back 186 A. stroke volume |
front 187 What factors would make stroke volume greater?
| back 187 A. Increased end-diastolic volume and decreased end-systolic volume |
front 188 Which factor does NOT increase stroke volume?
| back 188 D. Increased heart rate (would decrease stroke volume/less time to fill) |
front 189 Which of the following is measured in milliliters per beat?
| back 189 A. stroke volume |
front 190 What is the term for the volume of blood that is left in the ventricle after the QRS wave?
| back 190 B. end-systolic volume |
front 191 Under normal circumstances, the factors responsible for making delicate adjustments to the heart rate as circulatory demands change are __________.
| back 191 B. autonomic activity and circulatory hormones |
front 192 During exercise, the most important control mechanism to increase cardiac output is __________.
| back 192 C. increased sympathetic activity to the ventricles |
front 193 What is meant by cardiac reserves?
| back 193 A. The difference between resting cardiac output and maximum cardiac output |
front 194 What is meant by the term afterload?
| back 194 A. How much tension or force the ventricle has to generate to push the blood out of the ventricle |
front 195 What effect does epinephrine have on the SA node?
| back 195 B. It increases heart rate |
front 196 Which of these organs is not found in the mediastinum?
| back 196 A. lungs |
front 197 Which wave is the largest in the electrocardiogram?
| back 197 B. R wave |
front 198 Ventricular systole begins with the __________.
| back 198 D. closing of the mitral valve |
front 199 The wall of the left ventricle is thicker than the right; the left ventricle pumps more blood than the right. Are these two statements true or false?
| back 199 C. The first is true, second is false |
front 200 Which of these is not needed to determine cardiac output?
| back 200 A. blood pressure |
front 201 Which of these responses by the heart will sympathetic stimulation not cause?
| back 201 A. Increased end-systolic volume |
front 202 The heart is actually (one, two, or three) pumps? | back 202 2 (pulmonary circuit and the systemic circuit) |
front 203 Which heart chamber pumps unoxygenated blood out the pulmonary trunk?
| back 203 A. the right ventricle (to the lungs) |
front 204 Which heart chamber receives blood from the pulmonary veins?
| back 204 B.left atrium |
front 205 Which chamber pumps oxygenated blood out the aorta to the systemic circuit?
| back 205 C. left ventricle |
front 206 Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.
| back 206 B. ventricular diastole |
front 207 Which of the following is correct about the filling of the ventricles?
| back 207 A. blood flows passively into the ventricles through open AV valves. |
front 208 Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.
| back 208 A. Pressure in the atria would be greater than the pressure in the ventricles (higher pressure in the atria than in the ventricles forces the AV valves to open and blood moves into the ventricles). |
front 209 What causes the aortic semilunar valve to close?
| back 209 A. greater pressure in the aorta than in the left ventricle |
front 210 Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.
| back 210 B.isovolumetric contraction, ventricular ejection, isovolumetric relaxation |
front 211 Increased pressure in the ventricles would close what valve(s)?
| back 211 B. AV valves only |
front 212 Stewart suffers from bradycardia. Which type of drug might be a candidate to treat his condition?
| back 212 B. glucagon (increases heart rate and myocardial contractility, and improves atrioventricular conduction) |
front 213 How is heart rate controlled?
| back 213 D. All the listed answers are correct. |
front 214 With the force of the head-on collision, the patient’s chest collided with the steering wheel, causing fractures of the anterior chest wall, including the sternum and ribs. The heart itself, located just deep to the sternum, was injured and began bleeding into the pericardial cavity. What is normally found in the pericardial cavity?
| back 214 C. pericardial fluid |
front 215 Dr. Jim knew this victim was suffering from cardiac tamponade due to blood in the pericardial space. The blood in the pericardial cavity compressed the heart, squeezing the atria and ventricles so the atria could not fill. What vessels fill the right atria?
| back 215 B. superior and inferior vena cava |
front 216 Identify the most muscular chamber.
| back 216 The left ventricle (the left ventricle is responsible for pumping blood out to the body) |
front 217 Name the inner lining of the heart.
| back 217 A. endocardium (The endocardium is the smooth, slick lining of the chambers of the heart. Endocardium is a continuation of endothelium that lines blood vessels. Both endocardium and endothelium are composed of simple squamous epithelial tissue, which minimizes friction between the wall of the chamber/vessel and the blood.) |
front 218 Name the needle like ridges of muscle lining the ventricles.
| back 218 A. trabeculae carneae |
front 219 Blood on the right never mixes with blood on the left, once the heart is fully developed. T/F | back 219 True. Once fetal modifications (i.e. foramen ovale, ductus arteriosus) close following delivery of the infant, blood on the right side of the heart should not mix with blood on the left side of the heart. |
front 220 What is the function of the coronary circulation?
| back 220 C. Provide a blood supply to the heart (the coronary circulation provides oxygenated blood to the heart through coronary arteries) |
front 221 What is the ligamentum arteriosum?
| back 221 C. a remnant of the ductus arteriosus (the ductus arteriosus is a fetal shunt that connects the pulmonary trunk to the aorta). |
front 222 Which chamber of the heart exits into the pulmonary trunk?
| back 222 A. The right ventricle pumps deoxygenated blood through the pulmonary semilunar valve into the pulmonary trunk to be distributed to the lungs. |
front 223 The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human. T/F | back 223 True (the brachiocephalic artery is the first major vessel to exit the arch of the aorta) |
front 224 What does the ECG wave tracing represent?
| back 224 A. electrical activity in the heart |
front 225 What does the QRS complex represent in the ECG wave tracing?
| back 225 A. ventricular depolarization |
front 226 Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?
| back 226 A. AV node (slows down the impulse giving the atria time to contract before the ventricles contract) |
front 227 Which of the following statements is true about the SA (sinoatrial) node?
| back 227 D. All of these statements about the SA node are true. |
front 228 Passive refilling of the heart occurs during which phase of the cardiac cycle?
| back 228 B. ventricular diastole |
front 229 Which of the following factors will decrease cardiac output?
| back 229 C. stimulation of the vagus nerve (parasympathetic stimulation comes from the vagus nerve) |
front 230 If you know both the heart rate and stroke volume, you can calculate the __________.
| back 230 D. cardiac output |
front 231 The __________ valve prevents backward flow of blood into the left ventricle.
| back 231 A. aortic |
front 232 Heart rate is controlled by __________.
| back 232 B. both the right vagus and sympathetic nerves |
front 233 The P wave of the electrocardiogram is closely followed by __________.
| back 233 C. contraction of both atria |
front 234 Which of these is an important difference between cardiac muscle and skeletal muscle?
| back 234 B. Cardiac muscle can't be tetanized |
front 235 The rapid depolarization phase in the ventricular action potential appears in the electrocardiogram as the __________.
| back 235 D. QRS complex |
front 236 The plateau phase of the ventricular action potential corresponds to the __________ phase of the electrocardiogram.
| back 236 B. ST segment |
front 237 The duration of the ventricular action potential is approximately equal to the __________ interval in the electrocardiogram.
| back 237 D. Q-T interval |
front 238 During ventricular systole the blood pressure __________ and ventricular volume __________.
| back 238 D. increases; decreases |
front 239 The volume of blood remaining in the ventricle as diastole begins is called the __________.
| back 239 A. end-systolic volume |
front 240 Which of these statements concerning the cardiac cycle is false?
| back 240 D. Ventricular systole begins at the peak of atrial systole. |
front 241 Which of the following will not increase heart rate?
| back 241 D. increased parasympathetic stimulation of the SA node |
front 242 Which of the following descriptions matches the term at the level of the third costal cartilage? A) pericardial cavity B) visceral pericardium C) base of heart D) aorta E) right atrium | back 242 C) base of heart |
front 243 In a(n) _______ part of the coronary circulation becomes blocked, and cardiac muscle cells die from lack of oxygen. A) coronary spasm. B) myocardial infarction. C) coronary thrombosis. D) angina pectoris. E) pulmonary embolism. | back 243 B) myocardial infarction. |
front 244 Blood is supplied to the muscular wall of the right atrium by the A) brachiocephalic artery. B) right coronary artery. C) left coronary artery. D) phrenic arteries. E) pulmonary arteries. | back 244 B) right coronary artery (supplies right atrium, portions of both ventricles, portions of the conducting system) |
front 245 Why is the left ventricle much larger than the right ventricle? | back 245 It has to pump blood through the large systemic circuit, the right ventricle only has to pump blood to the lungs. |
front 246 The great cardiac vein drains blood from the heart muscle to the (a) left ventricle, (b) right ventricle, (c) right atrium, (d) left atrium. | back 246 (c) right atrium |
front 247 The serous membrane covering the outer surface of the heart is the (a) parietal pericardium, (b) endocardium, (c) myocardium, (d) visceral pericardium. | back 247 (d) visceral pericardium. |
front 248 The simple squamous epithelium covering the heart valves is the (a) epicardium, (b) endocardium, (c) myocardium, (d) cardiac skeleton. | back 248 (b) endocardium |
front 249 The heart is surrounded by the (a) pleural cavity, (b) peritoneal cavity, (c) abdominopelvic cavity, (d) mediastinum, (e) abdominal cavity. | back 249 (d) mediastinum |
front 250 The cardiac skeleton of the heart has which two of the following functions? (a) It physically isolates the muscle fibers of the atria from those of the ventricles, (b) It maintains the normal shape of the heart, (c) It helps distribute the forces of cardiac contraction, (d) It allows more rapid contraction of the ventricles, (e) It strengthens and helps prevent overexpansion of the heart. | back 250 (a) It physically isolates the muscle fibers of the atria from those of the ventricles (b) It maintains the normal shape of the heart |
front 251 Cardiac output is equal to the (a) difference between the end-diastolic volume and the end-systolic volume, (b) product of heart rate and stroke volume, (c) difference between the stroke volume at rest and the stroke volume during exercise, (d) stroke volume less the end-systolic volume, (e) product of heart rate and blood pressure. | back 251 (b) product of heart rate and stroke volume |
front 252 During diastole, a chamber of the heart (a) relaxes and fills with blood, (b) contracts and pushes blood into an adjacent chamber, (c) experiences a sharp increase in pressure, (d) reaches a pressure of approximately 120 mm Hg. | back 252 (a) relaxes and fills with blood |
front 253 During the cardiac cycle, the amount of blood ejected from the left ventricle when the semilunar valve opens is the (a) stroke volume (SV), (b) end-diastolic volume (EDV), (c) end-systolic volume (ESV), (d) cardiac output (CO). | back 253 (a) stroke volume (SV) |
front 254 The cells of the conducting system differ from the contractile cells of the heart in that (a) conducting cells are larger and contain more myofibrils, (b) contractile cells exhibit prepotentials, (c) contractile cells do not normally exhibit automaticity, (d) both a and b are correct. | back 254 (c) contractile cells do not normally exhibit automaticity |
front 255 Which of the following is longer? (a) the refractory period of cardiac muscle, (b) the refractory period of skeletal muscle. | back 255 (a) the refractory period of cardiac muscle |
front 256 If the papillary muscles fail to contract, (a) the ventricles will not pump blood, (b) the atria will not pump blood, (c) the semilunar valves will not open, (d) the AV valves will not close properly, (e) none of these happen. | back 256 (d) the AV valves will not close properly |
front 257 Cardiac output cannot increase indefinitely because (a) the available filling time becomes shorter as the heart rate increases, (b) the cardiovascular centers adjust the heart rate, (c) the rate of spontaneous depolarization decreases, (d) the ion concentrations of pacemaker plasma membranes decrease. | back 257 (a) the available filling time becomes shorter as the heart rate increases |
front 258 What role do the chordae tendineae and papillary muscles play in the normal function of the AV valves? | back 258 Papillary muscles pull on the chordae tendineae which stops the cusps of the AV valves from swinging into the atria/stops backflow |
front 259 What are the valves in the heart, and what is the function of each? | back 259 Right and left AV prevent regurgitation, semilunar valves prevent regurgitation from aorta and pulmonary trunk into left and right ventricles |
front 260 Describe the three distinct layers that make up the heart wall. | back 260 (1) The epicardium is the visceral pericardium, which covers the outer surface of the heart. (2) The myocardium is the muscular wall of the heart, which forms both atria and ventricles. It contains cardiac muscle tissue and associated connective tissues, blood vessels, and nerves. (3) The endocardium is a squamous epithelium that covers the inner surfaces of the heart, including the valves. |
front 261 Trace the normal pathway of an electrical impulse through the conducting system of the heart. | back 261 SA node, internodal pathways, AV node, AV bundle, bundle branches, Purkinje fibers |
front 262 What is the cardiac cycle? What phases and events are necessary to complete a cardiac cycle? | back 262 The cardiac cycle comprises the events in a complete heartbeat. The cycle begins with atrial systole as the atria contract and push blood into the relaxed ventricles. As the atria relax (atrial diastole), the ventricles contract (ventricular systole), forcing blood through the semilunar valves into the pulmonary trunk and aorta. The ventricles then relax (ventricular diastole). For the rest of the cardiac cycle, both the atria and ventricles are in diastole; passive filling occurs. |
front 263 What three factors regulate stroke volume to ensure that the left and right ventricles pump equal volumes of blood? | back 263 Preload - stretch on heart before it contracts Contractility - forcefulness of contraction Afterload - pressure that must be exceeded for blood to be ejected from ventricles |
front 264 Describe the function of the SA node in the cardiac cycle. How does this function differ from that of the AV node? | back 264 SA node is pacemaker, AV node slows impulse |
front 265 What are the sources and significance of the four heart sounds? | back 265 The first sound (lubb) marks the start of ventricular contraction, is produced as the AV valves close and the semilunar valves open. The second sound (dupp) occurs when the semilunar valves close and the AV valves open, marking the start of ventricular diastole. The third heart sound is associated with blood flow into the ventricles, and the fourth sound is associated with atrial contraction. |
front 266 Differentiate between stroke volume and cardiac output. How is cardiac output calculated? | back 266 SV is volume of blood ejected by ventricle in single contraction (SV = EDV - ESV). CO is amount of blood pumped by left ventricle in one minute (CO = HR x SV) |
front 267 What factors influence cardiac output? | back 267 Stroke volume and heart rate |
front 268 What effect does sympathetic stimulation have on the heart? What effect does parasympathetic stimulation have on the heart? | back 268 Sympathetic excites, parasympathetic calms |
front 269 Describe the effects of epinephrine, norepinephrine, glucagon, and thyroid hormones on the contractility of the heart. | back 269 Excite, increase cardiac contraction |
front 270 What neurotransmitter does the vagus nerve release?
| back 270 C. acetylcholine |
front 271 The epicardium A) is also known as the parietal pericardium. B) is a layer of cardiac muscle. C) is the visceral pericardium. D) lines the heart chambers. E) is the pacemaker of the heart. | back 271 C) is the visceral pericardium. |
front 272 The heart valves have a double layer of __________ with a layer of __________ in between. A) epicardium, myocardium B) epicardium, endocardium C) myocardium, endocardium D) endocardium, connective tissue E) connective tissue, epicardium | back 272 D) endocardium, connective tissue |
front 273 Musculi pectinati are found in the __________ ; trabeculae carneae are found in the __________ . A) auricles, auricles B) auricles, ventricles C) ventricles, auricles D) ventricles, ventricles | back 273 B) auricles, ventricles |
front 274 The skeleton of the heart A) electrically insulates the atria from the ventricles. B) is composed of bones and cartilage. C) is the location of the pacemaker. D) is composed of calcified cardiac muscle. | back 274 A) electrically insulates the atria from the ventricles. |
front 275 Which of these structures is NOT present in cardiac muscle cells? A) desmosomes B) gap junctions C) smooth sarcoplasmic reticulum D) terminal cisternae E) transverse (T) tubules | back 275 D) terminal cisternae |
front 276 If the SA node becomes damaged and nonfunctional, which of these is the most likely to occur? A) The heart will stop. B) The ventricles will contract, but the atria will stop. C) Another part of the heart, possibly the AV node, will become the pacemaker. D) The heart will beat faster. E) The atria will keep contracting, but the ventricles will stop. | back 276 C) Another part of the heart, possibly the AV node, will become the pacemaker. |
front 277 Which of these statements concerning cardiac muscle is correct? A) Cardiac muscle has more sarcoplasmic reticulum than skeletal muscle. B) Cardiac muscle has a prolonged period of slow repolarization called the plateau phase. C) Cardiac muscle has a shorter refractory period than skeletal muscle. D) Depolarization of cardiac muscle occurs when K+ and Na+ diffuse into the cell. E) all of these are correct | back 277 B) Cardiac muscle has a prolonged period of slow repolarization called the plateau phase. |
front 278 Action potentials pass rapidly from one cardiac muscle cell to another because of A) intercalated disks and numerous gap junctions. B) large nerves with branches going to each cardiac muscle cell. C) the large voltage of cardiac action potentials. D) the plateau phase of the action potential. E) open Ca2+ channels. | back 278 A) intercalated disks and numerous gap junctions. |
front 279 The depolarization phase of the cardiac muscle action potential occurs when A) voltage-gated Ca2+ ion channels open. B) voltage-gated K+ ion channels open. C) voltage-gated Na+ ion channels open. D) both b and c | back 279 C) voltage-gated Na+ ion channels open. |
front 280 Early repolarization of cardiac muscle cells occurs when A) voltage-gated Ca2+ ion channels open. B) voltage-gated K+ ion channels open. C) voltage-gated Na+ ion channels close. D) both b and c | back 280 B) voltage-gated K+ ion channels open. |
front 281 Which of these conditions occur in the cardiac muscle cell during the plateau phase? A) voltage-gated Ca2+ ion channels are open B) voltage-gated K+ ion channels are open C) voltage-gated Na+ ion channels are closed D) all of these | back 281 D) all of these |
front 282 Which of these conditions occurs in the cardiac muscle cell during the final repolarization phase? A) voltage-gated Ca2+ ion channels are open B) voltage-gated K+ ion channels are open C) voltage-gated Na+ ion channels are open D) all of these | back 282 B) voltage-gated K+ ion channels are open (voltage-gated Ca2+ and Na+ ion channels are closed) |
front 283 Unlike other cardiac muscle cells, the movement of __________ into the pacemaker cells is primarily responsible for the depolarization phase of the action potential. A) Ca2+ ions B) K+ ions C) Na+ ions D) Cl- ions | back 283 A) Ca2+ ions |
front 284 Which of these conditions results in a prepotential in pacemaker cells? A) Na+ ions move into the cell through specialized Na+ ion channels. B) Membrane permeability to K+ ions increases. C) Voltage-gated Ca2+ ion channels close. D) all of these are correct | back 284 A) Na+ ions move into the cell through specialized Na+ ion channels. |
front 285 During the QT interval of the EKG, the A) atria contract and begin to relax. B) atria relax. C) ventricles contract and begin to relax. D) ventricles relax. | back 285 C) ventricles contract and begin to relax. |
front 286 Which of these conditions is most likely to cause bradycardia? A) ectopic action potentials in the atria B) damage to the tricuspid valve C) excessive sympathetic stimulation D) excessive parasympathetic stimulation E) too much coffee | back 286 D) excessive parasympathetic stimulation |
front 287 During the period of ejection in the cardiac cycle, the atrioventricular valves are __________ and the semilunar valves are __________ . A) closed, closed B) closed, open C) open, closed D) open, open | back 287 B) closed, open |
front 288 Blood flows neither into nor out of the ventricles during A) the period of isovolumic contraction. B) the period of isovolumic relaxation. C) systole. D) diastole. E) both a and b | back 288 E) both a and b |
front 289 At the end of __________ , the ventricles are 70% filled. A) active ventricular filling B) passive ventricular filling C) ventricular diastole D) ventricular systoleE)atrial systole | back 289 B) passive ventricular filling |
front 290 The average end-diastolic volume of the ventricles is about __________ , whereas the end-systolic volume is about __________ . A) 125 mL, 55 mL B) 125 mL, 0 mL C) 0 mL, 55 mL D) 0 mL, 125 mL E) 55 mL, 125 mL | back 290 A) 125 mL, 55 mL |
front 291 During the period of ejection, the left ventricular pressure reaches a high point of approximately A) 20 mm Hg. B) 60 mm Hg. C) 80 mm Hg. D) 100 mm Hg. E) 120 mm Hg. | back 291 E) 120 mm Hg. |
front 292 Preload A) is the extent to which the ventricular walls are stretched. B) if increased, causes a decrease in cardiac output. C) is the pressure in the aorta which contracting ventricles must overcome. D) is part of the extrinsic regulation of the heart. E) all of these | back 292 A) is the extent to which the ventricular walls are stretched. |
front 293 Increased venous return to the heart causes increased A) stroke volume. B) preload. C) cardiac output. D) force of contraction. E) all of these | back 293 E) all of these |
front 294 Parasympathetic nerve fibers A) are carried to the heart through the Accessory nerve (XI). B) extend to terminal ganglia within the wall of the heart. C) release the neurotransmitter norepinephrine. D) if stimulated, result in an increased heart rate. E) if stimulated, greatly increase stroke volume. | back 294 B) extend to terminal ganglia within the wall of the heart. |
front 295 When normal arterial blood pressure decreases, baroreceptors cause a response that A) decreases heart rate. B) decreases stroke volume. C) returns blood pressure to normal. D) results in parasympathetic stimulation of the heart. E) all of these | back 295 C) returns blood pressure to normal. |
front 296 If blood pH decreases and blood carbon dioxide increases, A) heart rate increases. B) stroke volume decreases. C) increased parasympathetic stimulation of the heart occurs. D) the change is detected by chemoreceptors in the pulmonary arteries. E) all of these | back 296 A) heart rate increases. |
front 297 Increased sympathetic stimulation of the heart A) increases the force of ventricular contraction. B) opens a larger number of calcium slow channels. C) increases the heart rate. D) increases cardiac output. E) all of these | back 297 E) all of these |
front 298 Generally, an increase in extracellular Ca2+ ions causes __________ force of contraction, and __________ heart rate. A) decreased, decreased B) decreased, increased C) increased, decreased D) increased, increased | back 298 C) increased, decreased |
front 299 Excess K+ ions in cardiac tissue cause heart rate and stroke volume to __________ and decreased extracellular K+ ions result in a __________ in heart rate. A) decrease, decrease B) decrease, increase C) increase, decrease D) increase, increase E) be unchanged, increase | back 299 A) decrease, decrease |
front 300 What types of tissue comprises the vavles of the heart? A. Dense regular connective tissue B. Dense irregular connective tissue C. Areolar connective tissue D. Hyaline cartilage E. Cardiac muscle tissue | back 300 B. Dense irregular connective tissue |
front 301 Stimulation of this nerve reduces heart rate. A. Cardiac accelerator nerve B. Hypoglossal nerve C. Medulla oblongata nerve D. Vagus nerve E. Phrenic nerve | back 301 D. Vagus nerve |
front 302 Which of the below factors would increase stroke volume? A. Increased preload, increased afterload, increased contractility B. Decreased preload, decreased afterload, decreased contractility C. Increased preload, decreased afterload, increased contractility D. Decreased preload, increased afterload, increased contractility E. Increased preload, increased afterload, decreased contractility | back 302 C. Increased preload, decreased afterload, increased contractility |
front 303 Which of the below reduces heart rate? A. Increased noradrenaline hormone B. Increased thyroid hormone C. Increased potassium levels D. Increased calcium levels E. Increased sympathetic stimulation | back 303 C. Increased potassium levels |
front 304 Cardiac muscle fibres electrically connect to neighbouring fibres by A. Desmosomes B. Intermediate discs C. Gap junctions D. Contractile fibres E. Chordae tendinae | back 304 C. Gap junctions |
front 305 This electrical event represents repolarization of the ventricle. A. R wave B. T wave C. S wave D. P wave E. Q wave | back 305 B. T wave |
front 306 Damage to the__________ is referred to as heart block A. SA node B. AV valves C. AV bundles D. AV node | back 306 D. AV node |
front 307 Which of the following is not an age-related change affecting the heart? A. Atherosclerosis B. Decline in cardiac reserve C. Fibrosis of cardiac muscle D. Thinning of the valve flaps | back 307 D. Thinning of the valve flaps |
front 308 Select the correct statement about cardiac output A. A slow heart rate increases end diastolic volume, stroke volume, and force of contraction B. Decreased venous return will result in increased end diastolic volume C. If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased D. Stroke volume increasees if end diastolic volume decreases | back 308 A. A slow heart rate increases end diastolic volume, stroke volume, and force of contraction |
front 309 What happens to blood flow when there is coarctation of the aorta? | back 309 It is decreased |