Introduction to the Cardiovascular System

1.

Several nursing students are creating a poster on the mechanism of the heart. What structure would they label as separating the right half of the heart from the left?
A)
Auricle
B)
Bundle of His
C)
Syncytia
D)
Septum
Ans:
D

Feedback:

The septum is a partition that separates the right and left halves of the heart. The right half receives deoxygenated blood from everywhere in the body and the left half receives oxygenated blood from the lungs. The auricle is an appendage attached to each atrium, which collects blood that is pumped into the ventricles by atrial contractions. Impulses are sent from the atria into the ventricles by way of the bundle of His, which then enters the septum and subdivides into three bundle branches that become a network of fibers that delivers the electrical impulse to the ventricular cells. The myocardium forms two intertwining networks, atrial and ventricular syncytia, which enable first the atria and then the ventricles to contract synchronously when excited by the same stimulus.

2.

A nurse is caring for a neonate born with a congenital heart anomaly. To better help the parents understand the impact of this disorder, the nurse begins by describing the usual flow of blood through the heart which takes what course?
A)
Deoxygenated blood from the lungs enters the left atrium through the pulmonary artery.
B)
Oxygenated blood from the lungs enters the right atrium through the pulmonary veins.
C)
Deoxygenated blood from the lungs enters the right atrium through pulmonary veins.
D)
Oxygenated blood from the lungs enters the left atrium through the pulmonary veins.
Ans:
D

Feedback:

Oxygenated blood from the lungs enters the left atrium through the pulmonary veins and passes through the mitral valve into the left ventricle, which contracts and ejects blood through the aortic valve into the aorta and out to the systemic circulation.

3.

A patient is scheduled to have a pacemaker implanted. The nurse knows pacemakers can be inserted to correct what problem?
A)
Increased blood pressure
B)
Increased pulse pressure
C)
Malfunction of the sinuatrial (SA) node
D)
Onset of oncotic pressure
Ans:
C

Feedback:

Pacemaker cells are found in the SA node of the heart, which controls cardiac contraction and relaxation, therefore controlling the overall heart rate. If the SA node malfunctions, a pacemaker would be indicated. Hypertension, increased pulse pressure, and onset of oncotic pressure would not be an indication for pacemaker insertion.

4.

What description of an artery, made by the nurse, is accurate?
A)
Connective tubes composed of simple endothelial cells
B)
Floppy capacitance tubes
C)
Rigid resistance tubes
D)
Tubes carrying blood into the heart
Ans:
C

Feedback:

The arteries are muscular, rigid, resistance tubes of the cardiovascular system that carry blood away from the heart. The veins are capacitance tubes that carry blood to the heart. Capillaries connect arteries and veins.

5.

A 54-year-old man has a myocardial infarction, resulting in left-sided heart failure. The nurse caring for the man is most concerned that he will develop edema in what area of the body?
A)
Abdominal
B)
Liver
C)
Peripheral
D)
Pulmonary
Ans:
D

Feedback:

Pulmonary edema can occur when the heart is damaged and the left side of the heart is unable to effectively pump blood returning from the right side of the heart into systemic circulation. This lack of blood movement out of the lungs results in an increased hydrostatic pressure in the capillary beds of the lungs and the result can be pulmonary edema. Abdominal, liver, and peripheral edemas occur when the right side of the heart is failing and the returning venous blood pools in the organs and periphery.

6.

A patient, diagnosed with heart failure, would like the nurse to explain what the diagnosis means. How will the nurse explain heart failure?
A)
The heart muscle cannot pump effectively causing a backup of blood.
B)
The hydrostatic pressure pushing fluid out of the capillaries is lower than the oncotic pressure.
C)
The decrease in venous pressure from the backup of blood increases hydrostatic pressure.
D)
Increased protein leads to reduced oncotic pressure and inability to pull fluid into the system.
Ans:
A

Feedback:

Heart failure occurs when the heart muscle fails to do its job of effectively pumping blood through the system and blood backs up and the system becomes congested. The rise in venous pressure that results from the backup of blood increases hydrostatic pressure on the venous end of the capillaries. The hydrostatic pressure pushing fluid out of the capillaries becomes greater than the oncotic pressure that is trying to pull the fluid back into the vessel, thus causing fluid to be lost into the body tissues. Protein loss can lead to a fall in oncotic pressure and an inability to pull fluid back into the vascular system.

7.

A patient who is on a ventilator has been declared brain dead. A family member asks the nurse how the heart can still function if his father’s brain is dead. What statement is an appropriate response by the nurse?
A)
“Death of the heart will follow brain death in a few hours.”
B)
“The heart is controlled by the brainstem, not the upper levels of the brain.”
C)
“The cardiovascular center in the medulla would not be reflected in any tests.”
D)
“The heart is self-controlled and does not depend on the brain to beat.”
Ans:
D

Feedback:

The heart can generate action potentials on its own and can function without connection to the rest of the body. The heart will continue to function as long as oxygen and glucose are supplied to it. The brain does not initiate heart functioning. The cardiovascular center in the medulla helps to regulate blood pressure, not heart function.

8.

The nurse is caring for a patient in the ICU; hypotension may be anticipated when the patient’s body produces insufficient quantities of what hormone?
A)
Calcitonin hormone
B)
Antidiuretic hormone (ADH)
C)
Growth hormone
D)
Melanocyte-stimulating hormone
Ans:
B

Feedback:

Antidiuretic hormone is released from the pituitary gland resulting from reduced plasma volume or increased plasma osmotic pressure, so it serves to help maintain blood pressure. Angiotensin II also releases aldosterone from the cortex of the suprarenal gland, which causes retention of sodium and water, leading to the release of ADH to retain water and increase blood volume. Calcitonin maintains a dense, hard bone matrix and lowers blood calcium levels. Growth hormone regulates cell division and protein synthesis necessary for normal growth. Melanocyte-stimulating hormone causes skin pigmentation in humans.

9.

The nurse is caring for a patient whose blood pressure is 120/78. What is the pulse pressure?
A)
22
B)
32
C)
42
D)
52
Ans:
C

Feedback:

The pulse pressure is the difference between systolic and diastolic pressure. The systolic pressure is usually 40 points greater than the diastolic pressure. A pulse pressure of over 50 points or less than 30 points is considered abnormal. This patient’s pulse pressure is 42 (120 minus 78).

10.

A patient is admitted to the cardiac unit with a diagnosis of a myocardial infarction (MI). The nurse notes that the patient is having regular premature ventricular contractions (PVCs). Why would the nurse be concerned?
A)
Blood is not efficiently pumped from the heart with PVCs.
B)
Healing of the myocardium will be disrupted.
C)
PVCs usually cause severe pain.
D)
PVCs make it difficult to make a definitive diagnosis.
Ans:
A

Feedback:

Arrhythmias can alter cardiac output that could affect every cell in the body. Arrhythmias usually do not cause pain, disrupt healing, or interfere with the diagnosis of an MI.

11.

The nurse is caring for a patient whose damaged ventricle is reducing left ventricular filling and causing a backup of blood into the left atrium. What valve is damaged in this patient?
A)
Mitral
B)
Pulmonic
C)
Aortic
D)
Tricuspid
Ans:
A

Feedback:

The valve between the atrium and ventricle on the left side of the heart, called the mitral or bicuspid valve, is composed of two leaflets or cusps that allow the left ventricle to fill with blood and then close to prevent backflow of blood into the left atrium. If this valve is damaged, contraction of the ventricle will push blood back into the left atrium and result in inadequate cardiac output. The pulmonic valve is located between the right ventricle and pulmonary artery. The aortic valve allows blood to flow from the left ventricle into the aorta. The tricuspid valve is the valve between the right atria and ventricle.

12.

How would the nurse calculate the patient’s pulse pressure?
A)
The ejection pressure minus the filling pressure
B)
The end-artery pressure minus the resting pressure
C)
The difference between the ejection and the resting pressures
D)
The filling pressure of the coronary artery minus the end-artery pressure
Ans:
C

Feedback:

The pressure that fills the coronary arteries is the difference between the systolic (ejection) pressure and the diastolic (resting) pressure. This is called the pulse pressure (systolic minus diastolic blood pressure readings). Options A, B, and D are not correct.

13.

The nurse takes the patient’s pulse and finds a regular rate at 44 beats/min. What area of the heart is controlling this patient’s heart rate?
A)
The atrioventricular (AV) node
B)
The bundle of His
C)
The Purkinje fibers
D)
The sinuatrial (SA) node
Ans:
D

Feedback:

The SA node generates an impulse about 90 to 100 times a minute, the AV node about 40 to 50 times a minute, and the complex ventricular muscle cells only about 10 to 20 times a minute.

14.

The nurse is caring for a patient with severe coronary artery disease (CAD) who is experiencing chest pain because the oxygen demand exceeds supply. What forces could potentially be lowered to reduce oxygen consumption? (Select all that apply.)
A)
Pulse pressure
B)
Afterload
C)
Stretch on the ventricles
D)
Heart rate
E)
Preload
Ans:
B, C, D, E

Feedback:

The primary forces that determine the heart’s use of oxygen or oxygen consumption include: Heart rate (the more the heart has to pump, the more oxygen it requires), preload (the more blood that is returned to the heart, the harder it will have to work to pump the blood around), afterload (the higher the resistance in the system, the harder the heart will have to contract to force open the valves and pump the blood along), and stretch on the ventricles (if the ventricular muscle is stretched before it is stimulated to contract, more actomyosin bridges will be formed, which will take more energy). Pulse pressure does not impact oxygen consumption.

15.

The patient has edema resulting from heart failure (HF) in both ankles. The nurse interprets this to mean the hydrostatic pressure is higher than what opposing pressure?
A)
Pulse pressure
B)
Edema pressure
C)
Fluid pressure
D)
Oncotic pressure
Ans:
D

Feedback:

Hydrostatic pressure pushing fluid out of the capillary is soon higher than the oncotic pressure that is trying to pull the fluid back into the vessel, causing fluid to be lost into the tissues. This shift of fluid accounts for the edema seen in association with HF. This transfer of fluid in the capillaries, called the capillary fluid shift, is carefully regulated by a balance between hydrostatic (fluid pressure) forces on the arterial end of the capillary and oncotic pressure (the pulling pressure of the large, vascular proteins) on the venous end of the capillary. Pulse pressure has nothing to do with edema. Edema pressure and fluid pressure do not exist.

16.

The nurse is explaining the normal conduction pattern of the heart to an adolescent with a newly diagnosed congenital heart anomaly. The nurse tells the patient that what serves as the pacemaker for the heart?
A)
The atrioventricular (AV) node
B)
The bundle of His
C)
The Purkinje fibers
D)
The sinuatrial (SA) node
Ans:
D

Feedback:

The SA node, which is located near the top of the right atrium, acts as the pacemaker of the heart. The SA node sends the signal to the AV node, and then to the bundle of His, and into the Purkinje fibers, but it is the SA node that sets the rate.

17.

The nurse is caring for an older adult patient who is displaying alterations in the conduction of impulses in the SA node which the nurse assesses as what?
A)
Cardiac gallop
B)
Tachycardia
C)
Cardiac dysrhythmias
D)
Heart murmurs
Ans:
C

Feedback:

Alterations in the generation of conduction of impulses in the heart cause arrhythmias (dysrhythmias), which can upset the normal balance in the cardiovascular system and lead to a decrease in cardiac output, affecting all of the cells of the body. Tachycardia is only one of the possible arrhythmias that may result. Cardiac gallop and murmurs in the older adult with no history of congenital anomalies is usually caused by a poorly functioning heart valve and not by an alteration in conduction.

18.

The nurse is caring for a patient with coronary artery disease and hypertension. The nurse explains to the patient that coronary artery disease disables what process that controls blood pressure?
A)
Capacitance system
B)
Ability of the arterioles to increase or decrease resistance
C)
Oncotic pressure
D)
Ability of the venules to return blood to the veins
Ans:
B

Feedback:

The entire arterial system contains muscles in the walls of the vessels all the way to the terminal branches or arterioles, which consist of fragments of muscle and endothelial cells. These muscles offer resistance to the blood that is sent pumping into the arterial system by the left ventricle, generating pressure. The arterial system is referred to as a resistance system. Its vessels can either constrict or dilate, thus increasing or decreasing resistance, respectively, based on the needs of the body. The capacitance system is the venous system and does not contribute to regulation of arterial blood pressure. Oncotic pressure acts to pull the fluid back into the vessel. The venules have no impact on regulation of arterial blood pressure.

19.

When a muscle acts as a pump what is a necessary property for the muscle to function efficiently?
A)
Antagonistic contraction
B)
Antagonistic relaxation
C)
Simultaneous contraction
D)
Simultaneous relaxation
Ans:
C

Feedback:

Simultaneous contraction is a necessary property for a muscle that acts as a pump. A hollow pumping mechanism must also pause long enough in the pumping cycle to allow the chambers to fill with fluid. The heart muscle relaxes long enough to ensure adequate filling; the more completely it fills, the stronger the subsequent contraction is. This occurs because the muscle fibers of the heart, stretched by the increased volume of blood that has returned to them, spring back to normal size. This property is defined through Starling’s law of the heart. Simultaneous relaxation or antagonistic contraction or relaxation is not necessary.

20.

The nurse is caring for a science professor with hypertension who asks for a more complete explanation of blood pressure. The nurse begins by explaining that the phase when the ventricle contracts and ejects blood out into the aorta is known as what?
A)
Systole
B)
Diastole
C)
Hypertension
D)
Ejection fraction
Ans:
A

Feedback:

Contraction of the ventricles is called systole. Each period of systole is followed by a period of diastole when the heart rests. Ejection fraction is a measurement of cardiac output, or the blood ejected with each ventricular contraction. Hypertension is defined as elevated blood pressure and may include either systole or diastole or both.

21.

When sodium gates open along the cell membrane and sodium rushes into the cell it results in the membrane no longer having a positive or negative side but being electrically the same on both sides. The nurse recognizes this period of the cardiac cycle as what?
A)
Depolarized
B)
Repolarized
C)
Polarity
D)
Action potential
Ans:
A

Feedback:

Phase 0 occurs when the cell reaches a point of stimulation. The sodium gates open along the cell membrane, and sodium rushes into the cell, resulting in a positive flow of electrons into the cell—an electrical potential. This is called depolarization. The membrane no longer has a positive side or pole and a negative side; instead it is depolarized, or, in other words, electrically the same on both sides. During depolarization, the cells cannot be forced to contract. Repolarization is when the sodium returns to the outside of the cell and potassium returns to the inside of the cell and the muscle is ready to contract again. Action potential is the ability of the heart to respond to an electrical stimulus. Polarity is the electrical charge.

22.

The nurse explains the normal conduction pathway to the patient and evaluates the patient understood when they provide what description of the conduction pathway in the heart?
A)
Sinuatrial (SA) node to bundle of His to atrioventricular (AV) node to Purkinje fibers
B)
SA node to AV node to Purkinje fibers to bundle of His
C)
SA node to bundle of His to Purkinje fibers to AV node
D)
SA node to AV node to bundle of His to Purkinje fibers
Ans:
D

Feedback:

The normal conduction route is SA node to AV node to bundle of His to Purkinje fibers. Therefore, options A, B, and C are incorrect.

23.

The patient has had a myocardial infarction. The nurse realizes the significance of this injury is damage to what layer of the heart?
A)
Endocardium
B)
Pericardium
C)
Myocardium
D)
Epicardium
Ans:
C

Feedback:

The fibers of the cardiac muscle, or myocardium, form two intertwining networks called the atrial and ventricular syncytia. A myocardial infarction impacts this layer, which results in reduced pumping ability. The endocardium is the inner lining of the heart that comes in contact with the blood. The pericardium is the sac around the heart. The epicardium is the outermost layer of the heart.

24.

The nurse is caring for a patient in a state of shock. The family asks the nurse why the patient is so sick. What is the nurse’s best response?
A)
The patient probably has an infection that is making him look so sick.
B)
The coronary arteries are not supplying adequate blood flow to the myocardium.
C)
The pumping action of the ventricles is diminished, resulting in blood backing up in his lungs.
D)
Low blood pressure means inadequate supply of oxygen to the body’s tissues.
Ans:
D

Feedback:

The pressure of the blood in the arteries needs to remain relatively high to ensure that blood is delivered to every cell in the body and to keep the blood flowing from high-pressure to low-pressure areas. The pressure can fall dramatically—this is called hypotension—from loss of blood volume or from failure of the heart muscle to pump effectively. Severe hypotension can progress to shock and even death as cells are cut off from their oxygen supply. An infection would result in septic shock. Many types of shock exist. Inadequate supply of oxygen via the coronary arteries results in a myocardial infarction. Reduced pumping action of the heart is called heart failure.

25.

The nurse is caring for a patient with chronic renal failure. The patient asks the nurse how his kidney disease causes hypertension. What is the nurse’s best response?
A)
When blood flow to the kidney is under high pressure it causes release of antidiuretic hormone (ADH).
B)
When too much blood flows to the kidney, it causes vasodilation.
C)
When blood flow to the kidney declines, cells in the kidney release renin.
D)
Renin production converts ADH to angiotensin I in the liver.
Ans:
C

Feedback:

When blood flow to the kidneys is decreased, cells in the kidney release an enzyme called renin. Renin is transported to the liver, where it converts angiotensinogen (produced in the liver) to angiotensin I. Angiotensin I travels to the lungs, where it is converted by angiotensin-converting enzyme (ACE) to angiotensin II. Angiotensin II travels through the body and reacts with angiotensin II receptor sites on blood vessels to cause a severe vasoconstriction. This increases blood pressure and should increase blood flow to the kidneys to decrease the release of renin. Angiotensin II also causes the release of aldosterone from the cortex of the suprarenal glands, which causes retention of sodium and water, leading to the release of ADH to retain water and increase blood volume.

26.

The nurse is assigned to watch the cardiac monitors in the constant care unit and notes four different patients displaying arrhythmias. Which arrhythmia is the nurse’s highest immediate priority?
A)
Sinus bradycardia at a rate of 54 beats/min
B)
Atrial flutter
C)
Sinus tachycardia at a rate of 108 beats/min
D)
Ventricular fibrillation
Ans:
D

Feedback:

Ventricular fibrillation is seen as a bizarre, irregular, distorted wave. It is potentially fatal because it reflects a lack of any coordinated stimulation of the ventricles. The ventricles’ inability to contract in a coordinated fashion results in no blood being pumped to the body or the brain. Thus, cardiac output is totally lost. Sinus bradycardia, sinus tachycardia, and atrial flutter may all require attention but are not as life threatening as ventricular fibrillation.

27.

How does the nurse describe the cardiac action potential to a new coworker?
A)
The cycle of depolarization and repolarization
B)
The time it takes from the firing of the sinuatrial (SA) node to the contraction of the ventricles
C)
The time between the contraction of the atria and the contraction of the ventricles
D)
The cycle of the firing of the atrioventricular (AV) node and the contraction of the myocardium
Ans:
A

Feedback:

The action potential of the cardiac muscle cell consists of five phases: Phase 0 occurs when the cell reaches a point of stimulation. This is called depolarization. Phase 2, or the plateau stage, is a process called repolarization. Phase 4 is when spontaneous depolarization begins again. The action potential involves electrolytes and polarization and does not involve timing of the cardiac cycle.

28.

The nurse teaches a class on the systems that control blood pressure and includes what systems in the discussion? (Select all that apply.)
A)
The capacitance system
B)
Aldosterone–antidiuretic hormone (ADH) system
C)
Difference between the systolic and the diastolic readings
D)
Stimulus from the sympathetic system
E)
Reflex control of blood volume
Ans:
B, D, E

Feedback:

Blood pressure is maintained by stimulus from the sympathetic system and reflex control of blood volume and pressure by the renin–angiotensin system and the aldosterone–ADH system. The difference between the systolic and the diastolic readings does nothing to control blood pressure. The capacitance system does not regulate blood pressure.

29.

A patient presents at the clinic complaining of shortness of breath, fatigue, and difficulty performing activities of daily living (ADLs). The nurse notes the bluish color around the patient’s mouth and fingernail beds. What would the nurse expect the patient has?
A)
A dysrhythmia
B)
Hypotension
C)
Heart failure
D)
Hypertension
Ans:
C

Feedback:

If the heart muscle fails to do its job of pumping blood through the system effectively, blood backs up and the system becomes congested. This is called heart failure (HF). In the case described, the patient does not present with symptoms characteristic of a dysrhythmia, hypotension, or hypertension.

30.

The nurse explains how the myocardium receives oxygen to the new graduate nurse beginning work in the constant care unit; she tells the new nurse the coronary arteries receive blood when?
A)
During diastole
B)
During systole
C)
When the heart is refractory
D)
When the aortic valve is open
Ans:
A

Feedback:

The coronary arteries receive blood during diastole, when the muscle is at rest and relaxed so that blood can flow freely into the muscle. When the ventricle contracts, it forces the aortic valve open, which in turn causes the leaflets of the valve to cover the openings of the coronary arteries.

31.

The nurse explains that the reason the left ventricle is so much larger than the right ventricle is what?
A)
The left ventricle needs to pump blood through the entire body.
B)
The left ventricle needs to pump blood through both lungs.
C)
The right ventricle pumps blood through the entire body.
D)
The right ventricle pulls blood back into the heart from the lungs.
Ans:
A

Feedback:

The left ventricle is much larger because it has to pump strongly enough to circulate blood through the entire body. The right ventricle pumps blood only to the lungs, which are nearby.

32.

The nurse is caring for a patient with hypertension and recognizes this will have what impact on afterload?
A)
Increased afterload
B)
Reduced afterload
C)
Unchanged afterload
D)
Initial increase and then decrease in afterload
Ans:
A

Feedback:

Blood pressure is a measure of afterload so the higher the patient’s blood pressure the higher the afterload. The higher the resistance in the system, the harder the heart will have to contract to force open the valves and pump the blood along. Options B, C, and D are not correct.

33.

The patient’s blood pressure is low due to shock and vasodilation of the blood vessels. The nurse recognizes this will have what impact on preload?
A)
Preload will increase.
B)
Preload will decrease.
C)
Preload will depend on afterload.
D)
Preload will vary with activity of the patient.
Ans:
A

Feedback:

Preload is the amount of blood brought back to the heart to be pumped through the body. Vasodilation and shock will reduce preload because the pressure in the system is reduced, pushing less fluid through the vessels.

34.

The patient has a diagnosis of atherosclerosis. When a branch of the coronary artery becomes completely blocked, what event will the nurse expect to occur?
A)
Heart failure
B)
Arrhythmia
C)
Myocardial infarction
D)
Hypertension
Ans:
C

Feedback:

The blood supply is most frequently altered, however, when the coronary vessels narrow and do not respond to stimuli to dilate and deliver more blood. This happens in atherosclerosis or coronary artery disease. The end result of this narrowing can be total blockage of a coronary artery, leading to hypoxia and eventual death of the cells that depend on that vessel for oxygen. This is called myocardial infarction (MI); as of 2010, it is the leading cause of death in the United States. An arrhythmia is an alteration in the conduction system. Heart failure is caused by ineffective pumping action of the heart muscle. Hypertension is an increase in blood pressure.

35.

The patient has an excessive production of antidiuretic hormone (ADH). The nurse expects what change in the patient’s blood pressure?
A)
Increase in blood volume will cause increase in blood pressure.
B)
Increase in water and sodium excretion will cause a decrease in blood volume.
C)
Increase in ADH production will cause an increase in renin production and hypertension.
D)
Increase in ADH production will decrease angiotensin production and hypotension.
Ans:
A

Feedback:

Release of ADH causes the kidney to retain water and increase blood volume. Increasing blood volume increases blood pressure.