Pathophysiology Mod 3 CoursePoint
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) "You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked." b) "With this amount of blockage, your red blood cells get through the vessel one-by-one and supply oxygen to the muscle." c) "You are just a lucky person since most people would have had a massive heart attack by now." d) "You must have been taking a blood thinner for a long time."
a) "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 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) Pulmonary arterial pressure (PAP) b) Systemic vascular resistance (SVR) c) Central venous pressure (CVP) d) Blood pressure
a) Pulmonary arterial pressure (PAP) The pulmonary arterial pressure is the main source of afterload work on the right heart.
A nurse is explaining the conduction system of the heart to a client who is experiencing an arrhythmia. Which would be the most appropriate explanation? a) Sinoatrial node (SA), internodal pathways, AV node, AV bundle, Purkinje fibers b) Internodal pathways, AV node, sinoatrial node (SA), AV bundle, Purkinje fibers c) Sinoatrial node (SA), AV bundle, internodal pathways, AV node, Purkinje fibers d) AV node, sinoatrial node (SA), AV bundle, Purkinje fibers, intermodal pathways
a) Sinoatrial node (SA), internodal pathways, AV node, AV bundle, Purkinje fibers The conduction system consists of the SA node, the internodal pathways, the AV node, the AV bundle, and the Purkinje fibers. The other options are not normal conduction patterns.
As part of their orientation to a cardiac care unit, a group of recent nursing graduates is receiving a refresher in cardiac physiology from the unit educator. Which of the following teaching points best captures a component of cardiac function? a) "Aortic pressure will exceed ventricular pressure during systole." b) "The diastolic phase is characterized by relaxation of ventricles and their filling with blood." c) "Recall that the heart sounds that we listen to as part of our assessments are the sounds of myocardium contracting." d) "Efficient heart function requires that the ventricles not retain any blood at the end of the cardiac cycle.
b) "The diastolic phase is characterized by relaxation of ventricles and their filling with blood." Diastole is associated with ventricular filling and relaxation. Cardiac output is not 100% or near to it with each cardiac cycle, and heart sounds are associated with valve closing. Ventricular pressure exceeds that of the aorta during systole.
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) "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." 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) "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."
b) "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." There are several forms of reentry. The first is anatomic reentry. It involves an anatomic obstacle around which the circulating current must pass and results in an excitation wave that travels in a set pathway. Arrhythmias that arise as a result of anatomic reentry are paroxysmal supraventricular tachycardias, as seen in WPW syndrome, atrial fibrillation, atrial flutter, etc. A=sinus node arrhythmias and SSS. B=arrhythmias caused by MI. D= third degree block or ventricular standstill, for example.
The semilunar valves of the heart open at the onset of the ejection period. Approximately what percentage of the stroke volume is ejected during the first quarter of systole? a) 40% b) 60% c) 70% d) 50%
b) 60%
When reviewing diagnostic test results and physical assessment data for a client with a history of stage II hypertension, which of the following would be of most concern to the nurse? a) A heart rate (HR) of 62 beats/minute b) An ejection fraction of 40% c) Blood pressure of 146/80 d) Point of maximum impulse is located midclavicular at the 5th intercostal space
b) An ejection fraction of 40% This ejection fraction is below normal (normal is about 55 to 75 percent) and indicates a poor prognosis. This low ejection fraction is a result of the complications of long-standing hypertension.
The heart consists of four valves. Which are the semilunar values? Select all that apply. a) Tricuspid b) Aortic c) Mitral d) Pulmonary
b) Aortic d) Pulmonary The heart's atrioventricular valves are the tricupsid and the mitral. The heart's semilunar valves are the pulmonary and aortic values.
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: a) Aortic valve b) Bicuspid valve c) Pulmonic valve d) Tricuspid valve
b) 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.
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 are clinically silent. c) Most ECG-detected ischemic events cause a great deal of pain. d) ECG monitoring is reliable only when the client remains still.
b) 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 nurse is reviewing the anatomy and physiology of the heart. What is the function of the right atrium? a) Pumps blood into the systemic circulation b) Receives blood returning to the heart from the systemic circulation c) Receives oxygenated blood from the lungs d) Pumps blood to the lungs
b) 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.
Which of the following vessel layers is made primarily of muscle? a) Tunica adventitia b) Tunica intima c) Tunica externa d) Tunica media
d) 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.
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) Small openings that allow large amounts of smaller molecular substances to filter through the gomeruli. c) Large pores so that substances can pass easily through the capillary wall. d) Endothelial cells that are joined by tight junctions that form a barrier to medication filtration.
b) 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 cardiac cycle describes the pumping action of the heart. Which statement is correct about systole? a) Atria contract and blood is ejected from the heart. b) Ventricles contract and blood is ejected from the heart. c) Atria relax and blood fills the heart. d) Ventricles relax and blood fills the heart.
b) 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.
An 80-year-old male client arrives for his yearly physical without any complaints and following the checkup the physician explains that he has noted atrial fibrillation (AF) on the client's ECG. Before the physician can explain the disorder the client becomes very upset and states he thinks he is going to die. The physician explains that atrial fibrillation involves the top chambers of the heart and that: a) atrial fibrillation is a disorganized ventricular rhythm with recurrent circuits. b) many people live with atrial fibrillation without even knowing they have it. c) the client will be placed on anticoagulants immediately. d) the client will experience severe palpitations.
b) many people live with atrial fibrillation without even knowing they have it. Many people live with atrial arrhythmias, including atrial fibrillation, without knowing the arrhythmia exists. Atrial arrhythmias are typically less serious because they do not impact the ability of the ventricles to pump. This client is at high risk to develop atrial fibrillation due to his advanced age; the rates of atrial fibrillation begin to increase over the age of 60 and males have a greater prevalence. It is true that atrial fibrillation is a disorganized rhythm; however it is not ventricular. The client may or may not need anticoagulation; there are other considerations to be made before these medications would be considered.
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) HR = CO + SV b) SV = HR x CO c) CO = SV x HR d) HR = SV x CO
c) CO = SV x HR Cardiac output = stroke volume x heart rate
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) Perform synchronized cardioversion b) Notify the patient's attending physician c) Defibrillate the patient d) Administer IV push atropine
c) 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.
Which of the following enzymes has a powerful vasodilator effect on arterioles and increases capillary permeability? a) Serotonin b) Prostaglandins c) Histamine d) Arachidonic acid
c) 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.
Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another? a) Turbulent b) Axially c) Laminar d) Crosswise
c) 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).
Which of the following is the correct sequence for blood flow through the heart? a) Left atrium - tricuspid valve - left ventricle - pulmonary artery - lungs - pulmonary vein -right atrium - mitral valve - right ventricle - aorta b) Left atrium - bicuspid valve - left ventricle - pulmonary artery - lungs - pulmonary vein -right atrium - tricuspid valve - right ventricle - aorta c) Right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta d) Right atrium - bicuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein -left atrium - tricuspid valve - left ventricle - aorta
d) Right atrium - bicuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein -left atrium - tricuspid valve - left ventricle - aorta
A client has prominent jugular veins. What type of medical problem is associated with prominent jugular veins? a) Left sided heart failure b) Cerebral vascular accident c) Shock d) Right sided heart failure
d) Right sided heart failure Right sided heart failure, not left sided heart failure, shock, or cerebral vascular accident, is seen with prominent jugular veins.
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) Atrial ectopic foci b) Parasympathetic nervous system c) Vagal nerve d) Sympathetic nervous system
d) 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.