Chapter 17 Patho taken from http://thepoint.lww.com/Book LEVEL 3 MASTERY
A heart failure client has an echocardiogram performed revealing an ejection fraction (EF) of 40%. The nurse knows this EF is below normal and explains to the client: a) "You need to increase the amount of exercise you do to get your heart muscle back in shape." b) "This means your heart is not pumping as much blood out of the heart with each beat." c) "This means you have a lot of pressure built-up inside your heart." d) "Your ventricular muscle is getting too stiff to beat normally."
"This means your heart is not pumping as much blood out of the heart with each beat." Ejection fraction is the percentage of diastolic volume ejected from the heart [left ventricle] during systole. Stroke volume is determined by the difference between end-diastolic and end-systolic volumes. Cardiac output is determined by stroke volume and heart rate. Cardiac reserve refers to the maximum percentage of increase in cardiac output that can be achieved above the normal resting level
A client asks why he has not had major heart damage since his cardiac catheterization revealed he has 98% blockage of the right coronary artery. The nurse's best response is: a) "With this amount of blockage, your red blood cells get through the vessel one-by-one and supply oxygen to the muscle." b) "You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked." c) "You must have been taking a blood thinner for a long time." d) "You are just a lucky person since most people would have had a massive heart attack by now."
"You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked." Collateral circulation is a mechanism for the long-term regulation of local blood flow. In the heart, anastomotic channels exist between some of the smaller arteries. These channels permit perfusion of an area by more than one artery. When one artery becomes occluded, these anastomotic channels increase in size, allowing blood from a patent artery to perfuse the area supplied by the occluded vessel. For example, persons with extensive obstruction of a coronary blood vessel may rely on collateral circulation to meet the oxygen needs of the myocardial tissue normally supplied by that vessel. There is no indication that the client is on a blood thinner.
A client with heart disease has the left ventricular ejection fraction measured. What is the normal left ventricular ejection when determined by angiocardiography? a) 45% - 65% b) 55% - 75% c) 65% - 85% d) 35% - 55%
55% - 75% The normal left ventricular ejection fraction is usually 55 percent to 75 percent when determined by angiocardiography.
A number of patients on an acute cardiac care unit of a hospital have diagnoses of impaired cardiac conduction. Which of the following patients is most deserving of immediate medical attention? a) A 69-year-old woman who has entered ventricular fibrillation. b) A 60-year-old woman who has just been diagnosed with a first-degree AV block. c) A 60-year-old man with premature ventricular contractions (PVC) and a history of atrial fibrillation. d) A 46-year-old man whose cardiac telemetry shows him to be in ventricular tachycardia.
A 69-year-old woman who has entered ventricular fibrillation. Ventricular fibrillation, or ventricular flutter, is a life-threatening emergency that would necessitate immediate intervention. Ventricular tachydardia is also a serious condition, but less so than ventricular fibrillation. PVCs and a first-degree AV block would not normally require emergency intervention.
In which of the following situations would blood be most likely to be rapidly relocated from central circulation to the lower extremities? a) A client is helped out of bed and stands up. b) A client reclines from a sitting to supine position. c) A client does isotonic exercises in a wheelchair. d) A client undergoes a stress test on a treadmill.
A client is helped out of bed and stands up.
A client is admitted to the cardiac unit with a diagnosis of pericarditis. The nurse is teaching the patient about the anatomical location of the infection. The nurse evaluates the effectiveness of the teaching when the client correctly identifies which of the following as the location of the pericardium? a) The innermost lining of the heart chambers b) A membranous sac that encloses the heart c) The outer muscular layer of the heart d) The electrical conduction system of the heart
A membranous sac that encloses the heart
A nurse is caring for a client with right heart failure caused by pulmonary hypertension. Which hemodynamic parameter is most appropriate for the nurse to monitor? a) Systemic vascular resistance (SVR) b) Central venous pressure (CVP) c) Blood pressure d) Pulmonary arterial pressure (PAP)
B Pulmonary arterial pressure (PAP) The pulmonary arterial pressure is the main source of afterload work on the right heart.
A client's echocardiogram identified a narrowed valve that has resulted in a decreased blood flow between the left atria and left ventricle. The nurse would interpret this as the:
Bicuspid valve The bicuspid valve, (also called the mitral) controls the flow of blood between the left atria and left ventricle. The aortic valve controls flow between the left ventricle and aorta. The tricuspid controls the flow between the right atria and ventricle. The pulmonic valve controls flow between the right ventricle and pulmonary artery
An 81-year-old female client of a long term care facility has a history of congestive heart failure. The nurse practitioner caring for the client has positioned her sitting up at an angle in bed and is observing her jugular venous distention. Why is jugular venous distention a useful indicator for the assessment of the client's condition? a) Heart valves are not capable of preventing backflow in cases of atrial congestion. b) Blood backs up into the jugular vein because there are no valves at the point of entry into the heart. c) Increased cardiac demand causes engorgement of systemic blood vessels, of which the jugular vein is one of the largest. d) Peripheral dilation is associated with decreased stroke volume and ejection fraction.
Blood backs up into the jugular vein because there are no valves at the point of entry into the heart. Because there are no valves at the entry points to the atria, congestion can result in engorgement of the jugular veins which are proximal to the heart. Increased cardiac demand is not associated with engorgement of vessels or peripheral dilation
The efficiency of the heart as a pump often is measured in the amount of blood the heart pumps per minute. Which is the correct formula to figure out the cardiac output? a) CO = SV x HR b) HR = CO + SV c) HR = SV x CO d) SV = HR x CO
CO = SV x HR
Which of the following blood vessels function without the benefit of having walls comprised of three muscular layers? a) Arterioles b) Capillaries c) Arteries d) Veins
Capillaries The capillaries are small, thin-walled vessels that link the arterial and venous sides of the circulation and allow the exchange of oxygen and metabolites generated by the various tissues. The walls of all blood vessels, except the capillaries, are composed of three layers: tunica externa, tunica media, and tunica intima.
Select the correct sequence of blood return to the heart. a) Capillaries, arterioles, arteries, right atrium b) Capillaries, arterioles, veins, left atrium c) Capillaries, venules, veins, right atrium d) Capillaries, venules, veins, left atrium
Capillaries, venules, veins, right atrium The correct pathway for blood returning back to the heart is the capillaries, venules, veins, and right atrium. The other options do not support normal blood flow.
The heart controls the direction of blood flow. What is the role of the aortic valve? a) Controls the direction of blood flow from the left side of the heart to the systemic circulation b) Controls the direction of blood flow from the left side of the heart to the lungs c) Controls the direction of blood flow from the atria to the ventricles d) Controls the direction of blood flow from the ventricles to the artia
Controls the direction of blood flow from the left side of the heart to the systemic circulation The heart valves control the direction of blood flow from the atria to the ventricles (the AV valves), from the right side of the heart to the lungs (pulmonic valves) and from the left side of the heart to the systemic circulation (aortic valve).
While intubated for surgery, a patient has inadvertently had his vagus nerve stimulated. What effect would the surgical team expect to observe? a) Decreased heart rate as a result of parasympathetic innervation of the heart b) Decreased heart rate as a result of impaired acetylcholine reuptake c) Decreased heart rate, contractility and afterload d) Decreased vascular perfusion due to parasympathetic stimulation
Decreased heart rate as a result of parasympathetic innervation of the heart Vagal stimulation results in lowered heart rate as a result of parasympathetic stimulation. Vascular perfusion, contractility and afterload would not be under direct effect. Acetylcholine reuptake would not be influenced.
A patient's electrocardiogram monitor begins to sound an alarm and shows sustained ventricular fibrillation. The patient is unconscious and without a pulse. Which of the following priority interventions should the nurse take? a) Defibrillate the patient b) Perform synchronized cardioversion c) Notify the patient's attending physician d) Administer IV push atropine
Defibrillate the patient Immediate defibrillation using a nonsynchronized, direct-current electrical shock is mandatory for ventricular fibrillation and for ventricular flutter that has caused loss of consciousness
The school nurse is doing a health class on the functional organization of the circulatory system. What is the function of the capillaries in the circulatory system? a) Distribute oxygenated blood to the tissues b) Collect deoxygenated blood from the tissues c) Pump blood d) Exchange gases, nutrients and wastes
Exchange gases, nutrients and wastes The circulatory system consists of the heart which pumps blood, the arterial system which distributes oxygenated blood to the tissues, the venous system which collects deoxygenated blood from the tissues and returns it to the heart, and the capillaries where exchange of gases, nutrients and waste takes place.
Which of the following enzymes has a powerful vasodilator effect on arterioles and increases capillary permeability? a) Arachidonic acid b) Prostaglandins c) Serotonin d) Histamine
Histamine has a powerful vasodilator effect on arterioles and has the ability to increase capillary permeability, allowing leakage of both fluid and plasma proteins into the tissues. Serotonin causes vasoconstriction and plays a major role in control of bleeding. Prostaglandins produce either vasoconstriction or vasodilation.
The nurse is assisting a patient who had a myocardial infarction 2 days ago during a bath. The patient suddenly lost consciousness and the nurse was unable to feel a pulse. Cardiopulmonary resuscitation was begun and the patient was connected to the monitor with a gross disorganization without identifiable waveforms or intervals observed. Which of the following is a priority intervention at this time? a) Immediate defibrillation b) Administration of atropine c) Applying a transcutaneous pacemaker d) Synchronized cardioversion
Immediate defibrillation The classic electrocardiographic pattern of ventricular fibrillation is that of gross distortion without identifiable waveforms or or intervals. When the ventricles do not contract, there is no cardiac output, and there are no palpable or audible pulses. Immediate defibrillation using a nonsynchronized, direct-current electrical shock is mandatory for ventricular fibrillation and for ventricular flutter that has caused loss of consciousness.
A client has suffered damage to his pericardium following a motor vehicle accident. Which consequence could be a possible complication of damaged pericardium that his care providers should assess for? a) Reduced protection from infectious organisms b) Increased friction during the contraction/relaxation cycle c) Impaired physical restraint of the left ventricular d) Impaired regulation of myocardial contraction
Impaired regulation of myocardial contraction Regulation of myocardial contraction is not a role of the fibrous covering around the heart. The pericardium does restrain the left ventricle, reduce friction by way of fluid in the pericardial cavity and provide a physical barrier to infection
A client has experienced sympathetic nervous stimulation of the heart. The nurse is aware that the client may manifest which of the following? a) Decreased rate and force of contraction b) Decreased contractility and decreased heart rate c) Increased heart rate and increased contractility d) Increased heart rate and decreased contractility
Increased heart rate and increased contractility The sympathetic nervous system has an excitatory influence on heart rate and contractility, and it serves as the final common pathway for controlling the smooth muscle tone of the blood vessels. With stimulation, both heart rate and contractility would increase.
Which of the following is the greatest diagnostic limitation of an electrocardiogram (ECG)? a) It documents only current cardiac function. b) It is an expensive diagnostic tool. c) It is an invasive procedure. d) It can interfere with the heart's conduction system.
It documents only current cardiac function. The resting ECG is the first approach to the clinical diagnosis of disorders of cardiac rhythm and conduction, but it is limited to events that occur during the period the ECG is being monitored. The other options are not accurate statements regarding an ECG
Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another? a) Axially b) Laminar c) Turbulent d) Crosswise
Laminar Laminar blood flow reduces friction by allowing the blood layers to slide smoothly over one another, with the axial layer having the most rapid rate of flow. Axially, crosswise, and turbulent blood flow would result in increased friction. In turbulent flow, the laminar stream is disrupted and the flow becomes mixed, moving radially (crosswise) and axially (lengthwise).
When the semilunar valves open it signals the onset of the ejection period. The aortic pressure reflects changes in the ejection of blood from which part of the heart? a) Left atrium b) Right atrium c) Left ventricle d) Right ventricle
Left ventricle The aortic pressure reflects changes in the ejection of blood from the left ventricle, not the right ventricle or atrium.
The heart is a four-chambered pump. What is the function of the right ventricle? a) Receives blood returning to the heart from the systemic circulation b) Pumps blood into the systemic circulation c) Receives oxygenated blood from the lungs d) Pumps blood to the lungs
Pumps blood to the lungs The right atrium receives blood returning to the heart from the system circulation. The left atrium receives oxygenated blood from the lungs. The right ventricle pumps blood to the lungs. The left ventricle pumps blood into the systemic circulation
The nurse is reviewing the anatomy and physiology of the heart. What is the function of the right atrium? a) Receives oxygenated blood from the lungs b) Pumps blood to the lungs c) Receives blood returning to the heart from the systemic circulation d) Pumps blood into the systemic circulation
Receives blood returning to the heart from the systemic circulation The right atrium receives blood returning to the heart from the system circulation. The left atrium receives oxygenated blood from the lungs. The right ventricle pumps blood to the lungs. The left ventricle pumps blood into the systemic circulation.
The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent? a) Depolarization of the sinoatrial node b) Depolarization of the ventricular conduction system c) Repolarization of the atrium d) Repolarization of the ventricles
Repolarization of the ventricles The P wave represents the depolarization of the sinoatrial node. The QRS complex represents the depolarization of the ventricles. The T wave represents repolarization of the ventricles, not the atrium.
A client has had an acute myocardial infarction. The brother of the client has a history of angina. The client asks how they will know if the brother's pain is angina or if the brother is actually having an MI. Which statement is correct? a) Chest pain with angina only occurs during the day; MI pain is more likely at night. b) Rest and intake of nitroglycerin relieve chest pain with angina; they do not relieve chest pain with an MI. c) Pain is more severe and lasts longer with angina than with an MI. d) Chest pain with angina only occurs at rest; MI pain occurs during a stressful time.
Rest and intake of nitroglycerin relieve chest pain with angina; they do not relieve chest pain with an MI. Explanation: Rest and intake of nitroglycerin relieve chest pain with angina but not with an MI. Pain with angina and MI is an subjective symptom for each client. Pain with angina and MI can occur at a variety of times
Which of the following is the correct sequence for blood flow through the heart? a) Left atrium - bicuspid valve - left ventricle - pulmonary artery - lungs - pulmonary vein -right atrium - tricuspid valve - right ventricle - aorta b) Left atrium - tricuspid valve - left ventricle - pulmonary artery - lungs - pulmonary vein -right atrium - mitral valve - right ventricle - aorta c) Right atrium - bicuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein -left atrium - tricuspid valve - left ventricle - aorta d) Right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta
Right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta The correct pathway for blood flow through the heart is the right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta.
When trying to explain to a new dialysis patient the movement of substances through the capillary pores, the nurse will explain that in the kidneys, the glomerular capillaries have: a) No capillary openings since this would lead to extensive hemorrhage. b) Endothelial cells that are joined by tight junctions that form a barrier to medication filtration. c) Small openings that allow large amounts of smaller molecular substances to filter through the gomeruli. d) Large pores so that substances can pass easily through the capillary wall.
Small openings that allow large amounts of smaller molecular substances to filter through the gomeruli. The glomerular capillaries in the kidneys have small openings called fenestrations that pass directly through the middle of the endothelial cells. This allows large amounts of small molecular and ionic substances to filter through the glomeruli without having to pass through the clefts between the endothelial cells.
The health care provider is concerned that a client has developed a decrease in cardiac output. Cardiac output may be calculated as: a) Stroke volume × heart rate b) Blood pressure × stroke volume c) Blood pressure × heart rate d) Stroke volume × respiratory rate
Stroke volume × heart rate The cardiac output (CO) is a product of the stroke volume and the heart rate (HR) and can be expressed as CO = SV × HR.
An ECG technician is placing leads on a patient who has presented to the emergency department with a sudden onset of chest pain. The technician would recognize which of the following facts about the placement of leads and the achievement of a clinically accurate ECG? a) A total of 12 chest leads is necessary to attain the most accurate ECG. b) Limb leads measure the electrical activity of the heart indirectly through the activity of adjacent skeletal muscle. c) The chest leads measure electrical activity on the horizontal plane, while limb leads measure it on the vertical plane. d) The electrical potential recorded by a lead on an extremity will vary significantly depending on where the lead is placed on the extremity.
The chest leads measure electrical activity on the horizontal plane, while limb leads measure it on the vertical plane. A complete ECG is obtained by combining data from chest leads, which measure activity on the horizontal plane, and limb leads, corresponding to the vertical or frontal plane. The electrical potential recorded by a lead on an extremity should not vary significantly depending on where the lead is placed on the extremity, and limb leads do not measure electrical activity by way of skeletal muscle activity. A total of 12 leads, only six of which are on the chest, is necessary for a complete ECG.
Downstream peripheral pulses have a higher pulse pressure because the pressure wave travels faster than the blood itself. What occurs in peripheral arterial disease? a) Downstream peripheral pulses are greater than upstream pulses. b) Downstream peripheral pulses are increased even more than normal. c) The reflected wave is transmitted more rapidly through the aorta. d) The pulse decreases rather than increases in amplitude.
The pulse decreases rather than increases in amplitude. With peripheral arterial disease, there is a delay in the transmission of the reflected wave so that the pulse decreases rather than increases in amplitude.
Which of the following vessel layers is made primarily of muscle? a) Tunica media b) Tunica externa c) Tunica adventitia d) Tunica intima
Tunica media The outermost layer of a vessel is called the tunica externa or tunica adventitia. The middle layer is largely a smooth muscle layer that constricts to regulate and control the diameter of the vessel. The innermost layer is the tunica intima. (less)
The nurse identifies the blood vessel layer that constricts to regulate and control diameter as which of the following? a) Tunica adventitia b) Tunica externa c) Tunica intima d) Tunica media
Tunica media The tunica media, the middle layer, is largely a smooth muscle layer that constricts to regulate and control the diameter of the vessel. The tunica adventitia and tunica externa refer to the outermost layer of a vessel. The tunica intima refers to the innermost layer that prevents platelet adherence and blood clotting.
The nurse identifies the blood vessel layer that constricts to regulate and control diameter as which of the following? a) Tunica adventitia b) Tunica intima c) Tunica media d) Tunica externa
Tunica media The tunica media, the middle layer, is largely a smooth muscle layer that constricts to regulate and control the diameter of the vessel. The tunica adventitia and tunica externa refer to the outermost layer of a vessel. The tunica intima refers to the innermost layer that prevents platelet adherence and blood clotting.
Which of the following statements about vascular compliance is accurate? a) A continuous flow through the capillaries occurs primarily during systole. b) Arteries are much more distensible than veins. c) Arteries have thick muscular walls that constrict tightly, thereby ejecting blood without storing it for later use. d) Veins can act as a reservoir for storing large quantities of blood.
Veins can act as a reservoir for storing large quantities of blood. The most distensible of all vessels are the veins, which can increase their volume with only slight changes in pressure, allowing them to function as a reservoir for storing large quantities of blood that can be returned to the circulation when it is needed. Although arteries have a thicker muscular wall than veins, their distensibility allows them to store some of the blood that is ejected from the heart during systole, providing for continuous flow through the capillaries as the heart relaxes during diastole.
The cardiac cycle describes the pumping action of the heart. Which statement is correct about systole? a) Ventricles relax and blood fills the heart. b) Atria contract and blood is ejected from the heart. c) Ventricles contract and blood is ejected from the heart. d) Atria relax and blood fills the heart.
Ventricles contract and blood is ejected from the heart. Systole occurs when the ventricles contract and blood is ejected from the heart. Diastole occurs when the ventricles are relaxed and blood fills the heart.
Which of the following arrhythmias is considered to be the most fatal and requires immediate treatment? a) Ventricular fibrillation b) Atrial flutter c) Premature atrial contractions d) Premature ventricular contractions
Ventricular fibrillation represents severe derangements of cardiac rhythms that terminate fatally within minutes unless corrective measures are taken promptly. All of the other arrhythmias need to have further investigation into etiology, but are not immediately fatal.
Which of the following is true regarding pulmonary circulation? a) It is the larger of the two circulatory systems. b) It is a low-pressure system that allows for improved gas exchange. c) The system functions with an increased arterial pressure to circulate through the distal parts of the body. d) It consists of the left side of the heart, the aorta, and its branches.
b) It is a low-pressure system that allows for improved gas exchange.
The heart and blood vessels receive both sympathetic and parasympathetic innervation from neural control. What controls the parasympathetic-mediated slowing of the heart rate? a) The innervation center b) The cardioinhibitory center c) The medullary center d) The vasomotor center
b) The cardioinhibitory center The medullary cardiovascular neurons are grouped into three distinct pools that lead to sympathetic innervation of the heart and blood vessels and parasympathetic innervation of the heart. The first two, which control sympathetic-mediated acceleration of heart rate and blood vessel tone, are called the vasomotor center. The third, which controls parasympathetic-mediated slowing of heart rate, is called the cardioinhibitory center.
The heart consists of four valves. Which are the heart's atrioventricular valves? Select all that apply. a) Pulmonary b) Aortic c) Mitral d) Tricuspid
c) Mitral d) Tricuspid
ECG monitoring has been found to be more sensitive than a client's report of symptoms when identifying transient ongoing myocardial ischemia. Why is this? a) The ECG can look at ischemic events from different directions. b) Most ECG-detected ischemic events cause a great deal of pain. c) Most ECG-detected ischemic events are clinically silent. d) ECG monitoring is reliable only when the client remains still.
c) Most ECG-detected ischemic events are clinically silent. Persons with acute coronary syndrome are at risk for developing extension of an infarcted area, ongoing myocardial ischemia, and life-threatening arrhythmias. Research has revealed that 80% to 90% of ECG-detected ischemic events are clinically silent. Thus, ECG monitoring is more sensitive than a client's report of symptoms for identifying transient ongoing myocardial ischemia. Other answers are incorrect.
The cardiologist just informed a patient that they have a reentry circuit in the electrical conduction system in their heart. This arrhythmia is called Wolff-Parkinson-White (WPW) syndrome. After the physician has left the room, the patient asks the nurse to explain this to them. Which of the following statements most accurately describes what is happening? a) "You must have a large clot in one of your arteries that supply oxygenated blood to the special conduction cells in your heart." b) "For some reason, your electrical system is not on full charge so they will have to put in new leads and a pacemaker to make it work better." c) "This means that the SA node (which is the beginning of your heart's electrical system) has been damaged and is no longer functioning normal." d) "There is an extra, abnormal electrical pathway in the heart that leads to impulses traveling around the heart very quickly, in a circular pattern, causing the heart to beat too fast."
d) "There is an extra, abnormal electrical pathway in the heart that leads to impulses traveling around the heart very quickly, in a circular pattern, causing the heart to beat too fast."
The circulatory system can be divided into two parts. What does the systemic circulation include? Select all that apply. a) Pulmonary artery b) Right heart c) Capillaries d) Aorta
• Aorta • Capillaries The systemic circulation includes the aorta and capillaries. The pulmonary circulation includes the right heart and pulmonary artery.
A client admitted to the hospital with symptoms of Digoxin toxicity is told that a cardiac monitor will be necessary during the admission because the client may develop which of the following? Select all that apply. a) Incessant atrial tachycardia b) Atrial fibrillation c) Short Q-T syndrome d) Failure of the SA node e) Respiratory sinus arrhythmia
• Failure of the SA node • Incessant atrial tachycardia • Atrial fibrillation Digoxin (digitalis) is a cardiac glycoside and is use to increase cardiac contractility and slow conduction through the AV node. Digoxin is prescribed for clients with heart muscle insufficiency, such as congestive heart failure, to maximize the heart's contractility and also for those with atrial flutter and fibrillation to decrease the number and speed of atrial impulses through the AV node to the ventricles. Although Digoxin is a valuable medication in the treatment of many cardiac conditions, toxicity can cause many different arrhythmias such as sinus arrest, incessant atrial tachycardia, and atrial fibrillation.
The heart consists of four valves. Which are the semilunar values? Select all that apply.
• Pulmonary • Aortic The heart's atrioventricular valves are the tricupsid and the mitral. The heart's semilunar valves are the pulmonary and aortic values.
The nurse is reviewing the circulatory system. Which statements are correct about the functional organization of the circulatory system? Select all that apply. a) The capillaries pump blood. b) The venous system collects deoxygenated blood from the tissues . c) The arterial system distributes oxygenated blood to the tissues. d) The heart exchanges gases, nutrients and wastes.
• The arterial system distributes oxygenated blood to the tissues. • The venous system collects deoxygenated blood from the tissues . The circulatory system consists of the heart which pumps blood, the arterial system which distributes oxygenated blood to the tissues, the venous system which collects deoxygenated blood from the tissues and returns it to the heart, and the capillaries where exchange of gases, nutrients and waste takes place
A 20-year-old college student, with no past medical history, arrives at the emergency room complaining of severe palpitations and dizziness that started this morning following a night of studying. The student is very upset that this is happening because the final exams are the following day. The cardiac monitor shows a heart rate of 110, regular rhythm with occasional premature ventricular complexes. The nurse explains to the student that this can happen in healthy hearts and is usually caused by stimulation of which of the following? a) Parasympathetic nervous system b) Vagal nerve c) Sympathetic nervous system d) Atrial ectopic foci
Sympathetic nervous system premature ventricular complexes can occur in healthy hearts in response to stimulation of the sympathetic nervous system. This client states nighttime studying (possibly with coffee intake) and stress over upcoming exams, both of which can stimulate the sympathetic nervous system
