week 5 Ch.17 Mastery quiz

Which of the following is called the pacemaker of the heart?

Sinoatrial (SA) node

If the parasympathetic neurotransmitter releases acetylcholine, the nurse should anticipate observing what changes in the ECG pattern?

Slowing of heart rate to below 60 beats/minute -Acetylcholine, the parasympathetic neurotransmitter released during vagal stimulation of the heart, slows down the heart rate by decreasing the slope of phase 4. The catecholamines, the sympathetic nervous system neurotransmitters epinephrine and norepinephrine, increase the heart rate by increasing the slope or rate of phase 4 depolarization. Fibrillation is the result of disorganized current flow within the ventricle (ventricular fibrillation). Fibrillation interrupts the normal contraction of the atria or ventricles. In ventricular fibrillation, the ventricles quiver but do not contract. Thus, there is no cardiac output, and there are no palpable or audible pulses (i.e., cardiac standstill).

The heart is a four-chambered pump. What is the function of the right ventricle?

pumps blood through 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 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?

"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."

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:

"You have small channels between some of your arteries, so you can get blood from a patent artery to one severely blocked."

Which of the following is the correct sequence for blood flow through the heart?

Right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - mitral valve - left ventricle - aorta

A client has prominent jugular veins. What type of medical problem is associated with prominent jugular veins?

-Right sided heart failure

The heart consists of four valves. Which are the semilunar values? Select all that apply.

-aortic -pulmonary

The heart consists of four valves. Which are the heart's atrioventricular valves? Select all that apply.

-tricuspid -mitral

Select the correct sequence of blood return to the heart.

Capillaries, venules, veins, right atrium

In which of the following situations would blood be most likely to be rapidly relocated from central circulation to the lower extremities?

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 membranous sac that encloses the heart -The pericardium forms a fibrous covering around the heart, holding it in a fixed position in the thorax and providing physical protection and a barrier to infection. The pericardium is a tri-layer sac consisting of a tough, outer fibrous layer and a thin, inner serous layer

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?

CO= SV x HR

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.

The heart valves control the direction of blood flow. What is the function of the pulmonic valve?

Controls the direction of blood flow from the right side of the heart to the lungs

Following a hypertensive crisis, a client's family asks, "Why are the client's eyes so bloodshot?" The nurse responds that high arterial pressure:

Damages more fragile blood vessels like those in the eyes to the point of rupture -Excessively high arterial pressure and tissue perfusion can be dangerous because they may damage the more fragile blood vessels (like those inside the eyes). The myogenic control mechanisms rely on stretch of the vascular smooth muscle in the vessel wall. Therefore, it has been proposed that when the arterial pressure stretches the vessel, this in turn causes reactive vascular constriction that reduces the blood flow nearly back to normal.

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?

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.

When explaining to a patient why they only had minimal muscle damage following 99% occlusion of the left anterior descending artery, the nurse will explain this is primarily due to:

Development of collateral circulation that build channels between some of the smaller arteries usually when the flow is decreased gradually. -Collateral circulation is a mechanism for the long-term regulation of local blood flow. Anastomotic channels exist between some of the smaller arteries. These channels permit perfusion of an area by more than one artery. When the artery becomes occluded, these anastomotic channels increase in size, allowing blood from a patent artery to perfuse the area supplied by the occluded vessel.

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?

Exchange gases, nutrients and wastes -

Which of the following enzymes has a powerful vasodilator effect on arterioles and increases capillary permeability?

Histamine

The physician states that a client has adequate collateral circulation. The nurse interprets this as:

Long-term compensatory regulation of blood flow -Collateral circulation is a mechanism for the long-term regulation of local blood flow. In the heart and other vital structures, 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. Lymph node removal requires establishment of compensatory lymphatic drainage. The aging process produces the development of increased collagen

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?

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 experienced sympathetic nervous stimulation of the heart. The nurse is aware that the client may manifest which of the following?

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)?

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 is true regarding pulmonary circulation?

It is a low-pressure system that allows for improved gas exchange.

The heart is a four-chambered pump. Which chamber of the heart pumps blood into the systemic circulation?

Left ventricle

A nurse is assessing a female client and notes that her left arm is swollen from the shoulder down to the fingers, with non-pitting edema. The right arm is normal. The client had a left-sided mastectomy one year ago. Which of the following does the nurse suspect is the problem?

Lymphedema

The nurse is reviewing the anatomy and physiology of the heart. What is the function of the right atrium?

Receives blood returning to the heart from the systemic circulation

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?

Rest and intake of nitroglycerin relieve chest pain with angina; they do not relieve chest pain with an MI. -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.

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:

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.

During an assessment of a client with ankle swelling, the nurse observes jugular venous pulsations 5 cm above the sternal angle when the head of his bed is elevated 45 degrees. Which of the following is the correct interpretation of this finding?

The client has increased pressure related to right heart failure. -The jugular veins are normally flat or collapsed. Since there are no valves at the atrial sites (i.e., venae cavae and pulmonary veins) where blood enters the heart they can become prominent in severe right-sided heart failure. This means that excess blood is pushed back into the veins when the atria become distended.

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?

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.

Analysis has shown that a client's right atrial pressure is 30 mmHG. What is the most likely conclusion that the client's care team will draw from this piece of data?

The pressure is excessive given that the right atrium should be at atmospheric pressure.

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:

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.

Which of the following vessel layers is made primarily of muscle?

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.

A client has a blood pressure of 68/38 and fainted after donating a unit of blood. The client is experiencing low preload from loss of blood volume. What is preload?

Venous return to the heart -Preload is the amount of venous return to the heart. Afterload is the pressure in which the muscle exerts its contractile force in order to move blood into the aorta. Contractility is the ability of the heart to change its force of contraction without changing its resting length

The cardiac cycle describes the pumping action of the heart. Which statement is correct about systole?

Ventricles contract and blood is ejected from the heart.

The nurse is reviewing the circulatory system. Which statements are correct about the functional organization of the circulatory system? Select all that apply.

• 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.

When discussing the AV node's role in the electrical conduction of the heart with a client newly diagnosed with an AV block, which of the following statements are accurate? Select all that apply.

• When there is an AV block, impulses from the atria and ventricles beat independently of each other so, the heart rhythm is usually chaotic and not regular. • A block at the AV bundle of His interferes with the normal delay of the impulse, thereby interfering with complete ejection of blood from the atria prior to ventricular contraction. -The AV node connects the atrial and ventricular systems and normally provides for a one-way conduction between the atria and ventricles. The velocity of conduction through the AV junctional fibers is very slow, which greatly delays impulse transmission. A further delay occurs as the impulse travels through the transitional fibers and into the AV bundle, known as the bundle of His. This delay provides a mechanical advantage whereby the atria can complete their ejection of blood before ventricular contraction begins. Under normal circumstances, the AV node provides the only connection between the atrial and ventricular conduction systems. The atria and ventricles would beat independently of each other if the transmission of impulses through the AV node were blocked