Description

1. Question: Which statement made by a student indicates the healthcare professional needs to describe the pericardium again?
2. Question: The pericardium is made up of a surface layer of mesothelium over a thin layer of connective tissue. The healthcare professional would need to re-explain if the student stated the pericardium is made up of connective tissue and a layer of squamous cells. The other statements are accurate. Which cardiac chambers have the thinnest wall and why?
3. Question: The two atria have the thinnest walls because they are low-pressure chambers that serve as storage units and conduits for blood that is emptied into the ventricles. The ventricles have thicker walls in order to pump blood against resistance. Which chamber of the heart endures the highest pressures?
4. Question: Pressure is greatest in the left ventricle with a systolic range of 90 to 140 mmHg. The right ventricle is next with a systolic range of 15 to 28 mmHg, followed by the left and right atria, respectively. What is the process that ensures mitral and tricuspid valve closure after the ventricles are filled with blood?
5. Question: During ventricular relaxation, the two atrioventricular valves open and blood flows from the higher pressure atria to the relaxed ventricles. With increasing ventricular pressure, these valves close and prevent backflow into the atria as the ventricles contract. The chordae tendineae attach the bottom end of the AV valves to the papillary muscles. The endocardium covers beamlike projections of muscle tissue, called trabeculae carneae. The valves are not pulled closed by reduced atrial pressure. A student asks the healthcare professional to explain the function of the papillary muscles. What response by the professional is best?
6. Question: The papillary muscles are extensions of the myocardium that pull the cusps of the AV valves together and downward at the onset of ventricular contraction, thus preventing their backward expulsion into the atria. They do not close the semilunar valves or open the AV valves or semilunar valves. During the cardiac cycle, why do the aortic and pulmonic valves close after the ventricles relax?
7. Question: When the ventricles relax, blood fills the cusps and causes their free edges to meet in the middle of the vessel, closing the valve and preventing any backflow. The papillary muscles function in the tricuspid and mitral valves as do the chordae tendineae. Reduced pressure does not pull the valves closed. Oxygenated blood flows through which vessel?
8. Question: The four pulmonary veins, two from the right lung and two from the left lung, carry oxygenated blood from the lungs to the left side of the heart. All other veins carry deoxygenated blood. The superior vena cava returns deoxygenated blood from systemic circulation to the right atrium. The pulmonary arteries carry deoxygenated blood from the right side of the heart into the lungs. A healthcare professional tells a student that a patient has lost atrial kick. What would the student expect to see when examining this patient?
9. Question: Left atrial contraction, the atrial kick, provides a significant increase of blood to the left ventricle. This would help to increase cardiac output. With the loss of this atrial kick, the student would expect to find signs of decreased cardiac output such as decreased blood pressure or tachycardia. Loss of atrial kick would not improve dysrhythmias or increase serum troponin levels which usually indicate myocardial damage. Occlusion of the left anterior descending artery during a myocardial infarction would interrupt blood supply to which structures?
10. Question: The left anterior descending artery (LAD), also called the anterior interventricular artery, delivers blood to portions of the left and right ventricles and much of the interventricular septum. The circumflex artery supplies the left atrium and lateral wall of the left ventricle. The right coronary artery supplies the right ventricle and one of its branches is the right marginal branch. The interventricular sulcus and smaller branches of both ventricles are also supplied by the right coronary artery. Where are the coronary ostia located?
11. Question: Coronary arteries receive blood through openings in the aorta, called the coronary ostia. The coronary sinus empties into which cardiac structure?
12. Question: The cardiac veins empty only into the right atrium through another ostium, the opening of a large vein called the coronary sinus. During the cardiac cycle, which structure directly delivers action potential to the ventricular myocardium?
13. Question: Each cardiac action potential travels from the SA node to the AV node to the bundle of His (AV bundle), through the bundle branches, and finally to the Purkinje fibers and the ventricular myocardium, where the impulse is stopped. A patient has a problem with Phase 0 of the cardiac cycle. What electrolyte imbalance would the healthcare professional associate most directly with this problem?
14. Question: Phase 0 consists of depolarization and represents rapid sodium entry into the cell. A deficit of sodium could be a possible contributor. The other electrolyte disturbances would not be directly correlated to this problem.A healthcare professional is caring for a patient who has a delay in electrical activity reaching the ventricle as seen on ECG. What ECG finding would the healthcare professional associate with this problem?
15. Question: The PR interval is a measure of time from the onset of atrial activation to the onset of ventricular activation; it normally ranges from 0.12 to 0.20 sec. The PR interval represents the time necessary to travel from the sinus node through the atrium, the atrioventricular (AV) node, and the His-Purkinje system to activate ventricular myocardial cells. The measured PR of 0.28 sec is too long, signifying a delay in the conduction process from atrium to ventricle. The ST interval represents the time needed for ventricular depolarization. The QT interval is normally around 0.4 sec, but varies inversely with heart rate. The QRS measurement is within the normal range of less than or equal to 0.12 sec.The cardiac electrical impulse normally begins spontaneously in the sinoatrial (SA) node because of what reason?
16. Question: The electrical impulse normally begins in the SA node because its cells depolarize more rapidly than other automatic cells at a rate of 60 to 100 beats/min. The SA node’s location does not influence this activity. Other areas of the heart include the AV node and the Purkinje fibers. The vagus nerve causes the heart rate to slow as part of the parasympathetic nervous system. What period follows depolarization of the myocardium and represents a period during which no new cardiac potential can be propagated?
17. Question: During the absolute refractory period, no new cardiac action potential can be initiated by a stimulus. The other options do not reflect the time period in which no stimulation will produce a new cardiac potential. A patient has a disorder affecting ventricular depolarization. What ECG finding would the healthcare professional associate with this condition?
18. Question: The QRS complex represents the sum of all ventricular muscle cell depolarizations. If a patient had ECG findings suggestive of problems with this activity, there would be prolongation of the QRS interval. The PR interval reflects the amount of time needed for the action potential to travel from the atrium to the ventricle. QT interval variability is normal. An absence of P waves would indicate a problem with the SA node. What can shorten the conduction time of action potential through the atrioventricular (AV) node?
19. Question: Catecholamines speed the heart rate, shorten the conduction time through the AV node, and increase the rhythmicity of the AV pacemaker fibers. The vagal nerve is part of the sympathetic nervous system and stimulation will decrease heart rate. The SA node is responsible for generating the electrical activity of the heart, but is not responsible for the time it takes for it to travel through the AV node. A patient had a myocardial infarction that damaged the SA node, which is no longer functioning as the pacemaker of the heart. What heart rate would the healthcare provider expect the patient to have?
20. Question: If the SA node is damaged, then the AV node will become the heart’s pacemaker at a rate of approximately 40 to 60 spontaneous depolarizations per minute. The SA node normally fires at a rate of 60 to 100 beats/min. The Purkinje fibers can function as the heart’s pacemaker and will fire at a rate of around 40 beats/min. What is the effect of epinephrine on β3 receptors on the heart?
21. Question: β3 receptors are found in the myocardium and coronary vessels. In the heart, stimulation of these receptors opposes the effects of β1- and β2-receptor stimulation and negative inotropic effect. Thus β3 receptors may provide a safety mechanism that decreases myocardial contractility to prevent overstimulation of the heart by the sympathetic nervous system. Where in the heart are the receptors for neurotransmitters located?
22. Question: Sympathetic neural stimulation of the myocardium and coronary vessels depends on the presence of adrenergic receptors, which specifically bind with neurotransmitters of the sympathetic nervous system. The β1 receptors are found mostly in the heart, specifically the conduction system (AV and SA nodes, Purkinje fibers) and the atrial and ventricular myocardium, whereas the β2 receptors are found in the heart and also on vascular smooth muscle. β3 receptors are also found in the myocardium and coronary vessels. This selection is the only option that accurately identifies the location of the receptors for neurotransmitters. What enables electrical impulses to travel in a continuous cell-to-cell fashion in myocardial cells?
23. Question: The intercalated disks are thickened portions of the sarcolemma and enable electrical impulses to spread quickly in a continuous cell-to-cell (syncytial) fashion. A sarcolemma is a transparent sheath that surrounds nerve fibers. They are not subject to plaque buildup. The trabeculae carneae are beam-like projections of myocardial tissue. Bachmann bundles are part of the conduction system. Within a physiologic range, what does an increase in left ventricular end-diastolic volume (preload) result in?
24. Question: This concept is expressed in the Frank-Starling law; the cardiac muscle, like other muscles, increases its strength of contraction when it is stretched. An inotropic substance would increase the force of contraction and consist of hormones, neurotransmitters, or medications, and do not include volume. Afterload is the force against which the heart must pump. A decrease in repolarization would affect electrical activity. The healthcare professional explains to a student that the amount of volume of blood in the heart is directly related to the of contraction.
25. Question: As stated in the Frank-Starling law, the volume of blood in the heart at the end of diastole (the length of its muscle fibers) is directly related to the force (strength) of contraction during the next systole. This selection is the only option that accurately describes the relationship associated with the Frank-Starling law. Pressure in the left ventricle must exceed pressure in which structure before the left ventricle can eject blood?
26. Question: Pressure in the ventricle must exceed aortic pressure before blood can be pumped out during systole. The aorta is the only structure in which pressure must be less than the amount of blood in the left ventricle for ejection to occur. A healthcare professional is caring for a patient who has continuous increases in left ventricular filing pressures. What disorder would the professional assess the patient for?
27. Question: Pressure changes are important because increased left ventricular filling pressures back up into the pulmonary circulation, where they force plasma out through vessel walls, causing fluid to accumulate in lung tissues (pulmonary edema). Problems such as mitral regurgitation and mitral stenosis are valve problems, not directly related to this patient’s situation. Jugular vein distention can be a sign of fluid overload. The resting heart rate in a healthy person is primarily under the control of which nervous system?
28. Question: The resting heart rate in healthy individuals is primarily under the control of parasympathetic stimulation. The Bainbridge reflex is thought to be initiated by sensory neurons in which cardiac location?
29. Question: The Bainbridge reflex causes changes in the heart rate after intravenous infusions of blood or other fluid. The changes in heart rate are thought to be caused by a reflex mediated by volume receptors found only in the atria that are innervated by the vagus nerve. A healthcare professional cares for older adults in a skilled nursing facility. What should the professional assess for in these individuals related to cardiovascular functioning?
30. Question: The baroreceptor reflex is important in blood pressure control. Baroreceptor activity can decrease with age, slowing response to changes in blood pressure and posture. An older adult may not adjust rapidly to position changes, leading to falls and dizzy spells. Reflex control of total cardiac output and total peripheral resistance is controlled by what mechanism?
31. Question: Reflex control of total cardiac output and peripheral resistance includes (1) sympathetic stimulation of the heart, arterioles, and veins; and (2) parasympathetic stimulation of the heart only. Neither autonomic nor somatic controls are involved in this process. What is the most important negative inotropic agent?
32. Question: Chemicals affecting contractility are called inotropic agents. The most important negative inotropic agent is acetylcholine released from the vagus nerve. The most important positive inotropic agents produced by the body are norepinephrine released from the sympathetic nerves that supply the heart and epinephrine released by the adrenal cortex. Other positive inotropes include thyroid hormone and dopamine. The right lymphatic duct drains into which structure?
33. The right lymphatic duct drains lymph into the right subclavian vein only. A patient had a motor vehicle crash and suffered critical injuries to the brainstem. What physiological responses would the healthcare professional expect to see?
34. Question: The major cardiovascular control center is in the brainstem in the medulla with secondary areas in the hypothalamus, the cerebral cortex, the thalamus, and the complex networks of exciting or inhibiting interneurons (connecting neurons) throughout the brain. The brainstem specifically controls blood pressure and pulse, so a severe injury to this area would manifest with changes in blood pressure and pulse. Changes on the ECG and fluid overload would not occur due to this injury. What is an expected change in the cardiovascular system that occurs with aging?
35. Question: Arterial stiffening occurs with aging even in the absence of clinical hypertension. Aging is not responsible for the other conditions. What is the major determinant of the resistance that blood encounters as it flows through the systemic circulation?
36. Question: The muscle layer of the arterioles constricts or dilates depending on the stimulation it receives. The change in the diameter of the vessels determines the resistance to blood flow. Blood viscosity usually stays the same; however severe fluid loss can increase it, leading to an increase in resistance. This is not the major determinant however. The force of contraction does not determine resistance to flow. What physical sign does the healthcare professional relate to the result of turbulent blood flow through a vessel?
37. Question: Where flow is obstructed, the vessel turns or blood flows over rough surfaces. The flow becomes turbulent with whorls or eddy currents that produce noise, causing a murmur to be heard on auscultation. Increased blood pressure during stress is the result of sympathetic nervous system stimulation. A bounding pulse usually indicates fluid overload. Cyanosis would relate to a decrease in gas exchange and oxygenation. What is the major effect of a calcium channel blocker such as verapamil on cardiac contractions?
38. Question: The L-type, or long-lasting, channels are the predominant type of calcium channels and are the channels blocked by calcium channel-blocking drugs (verapamil, nifedipine, diltiazem). The major effect of these medications is to decrease the strength of cardiac contraction. These medications do not increase the rate of contractions or stabilize either rhythm of contractions or vessel response during contractions. An early diastole peak caused by filling of the atrium from peripheral veins is identified by which intracardiac pressure?
39. Question: The V wave is an early diastolic peak caused by the filling of the atrium from the peripheral veins. The A wave is generated by atrial contraction. The C wave is a small pressure increase seen after the A wave in early systole. The X descent follows the A wave and is produced by the descent of the tricuspid valve ring and by the ejection of blood from both ventricles. Which statements are true concerning the method in which substances pass between capillaries and the interstitial fluid? (Select all that apply.)
40. Question: Substances pass between the capillary lumen and the interstitial fluid in several ways: (1) through junctions between endothelial cells, (2) through fenestrations in endothelial cells, (3) in vesicles moved by active transport across the endothelial cell membrane, or (4) by diffusion through the endothelial cell membrane.