CH 25 STRUCTURE AND FUNCTION OF CARDIAC SYSTEM

Which blood vessels function without the benefit of having walls comprised of three muscular layers?

Capillaries

Which of the following is true regarding pulmonary circulation?

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

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."

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.

A client with a history of heart failure has the following echocardiogram results: heart rate 80 beats/minute; end-diastolic volume 120 mL; and end-systolic volume 60 mL. What is this client's ejection fraction (EF)?

50%

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

Pulmonary Aortic

A client with high blood pressure has swollen ankles. Which physiologic factor could relieve this condition?

A decrease in the hydrostatic pressure that drives fluid into the tissue

A client is admitted to the cardiac unit with a diagnosis of pericarditis. The nurse is teaching th client 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

A client is diagnosed with an abdominal aortic aneurysm that the physician just wants to "watch" for now. When teaching the client about signs/symptoms to watch for, the nurse will base the teaching on which physiologic principle?

As the aneurysm grows, more tension is placed on the vessel wall, which increases the risk for rupture.

During a physical examination of a client, the nurse palpates the point of maximal impulse (PMI) in the seventh intercostal space lateral to the left midclavicular line. What is the most appropriate action for the nurse to take?

Assess the clent for symptoms of left ventricular hypertrophy.

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 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

The heart controls the direction of blood flow. What is the role of the aortic valve?

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. What is the function of the pulmonic valve?

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

The nurse is caring for a client with severe aortic stenosis. What affect to cardiac afterload will the nurse note?

Greatly elevated systolic pressure when measured with hemodynamic setting

Humoral control of blood flow involves the effect of vasodilator and vasoconstrictor substances in the blood. Select the factor that has a powerful vasodilator effect on arterioles and increases capillary permeability.

Histamine

Release of which humoral factors will result in vasodilation?

Histamine

Which enzyme has a powerful vasodilator effect on arterioles and increases capillary permeability?

Histamine

A grandmother who works as a cook at a nearby school was recently hospitalized when she lost an extensive amount of blood in a work-related accident. The grandmother tells the nurse that she heard that she would keep feeling faint until the brain made more blood. The nurse knows that when the blood pressure dropped, the pressure in the carotid arteries decreased. This was detected by baroreceptors in the carotid arteries. What did the baroreceptors do?

Increase sympathetic stimulation of the heart and blood vessels

If a client experiences sympathetic nervous stimulation of the heart, the nurse will observe which changes in manifestations?

Increased heart rate and increased contractility

Which of the following blood flow patterns reduces friction, allowing the blood layers to slide smoothly over one another?

Laminar

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?

Left ventricle

Which related circulatory complication can result from surgical treatment for metastatic breast cancer?

Lymphedema in the affected arm

Nitroglycerin is the drug of choice in treating angina. What does nitroglycerin release into the vascular smooth muscle of the target tissues?

Nitric oxide

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?

Pulmonary arterial pressure (PAP)

When a client is experiencing a parasympathetic nervous system response to severe chest pain, the nurse will likely see which change in the client's vital signs?

Pulse rate below 59 beats/minute

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

Pumps blood to the lungs

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 (MI). The brother of the client has a history of angina. The client asks how he will know if his 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.

Following a kitchen accident with a knife, the client's cut has experienced a decrease in the amount of bleeding and has developed a clot. The nurse knows this is primarily a result of the release of which humoral factor?

Serotonin

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

The difference between the end-diastolic and end-systolic volumes is called what?

Stroke volume

The health care provider is concerned that a client has developed a decrease in cardiac output. Cardiac output may be calculated as:

Stroke volume × heart rate

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.

Downstream peripheral pulses have a higher pulse pressure because the pressure wave travels faster than the blood itself. What occurs in peripheral arterial disease?

The pulse decreases, rather than increases, in amplitude.

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

Tricuspid Mitral

The nurse identifies the blood vessel layer that constricts to regulate and control diameter as:

Tunica media

Which blood vessel layer is made primarily of muscle?

Tunica media

Preload, the stetch on the heart before contraction, is largely determined by which factor?

Venous blood return

A client has a blood pressure of 68/38 mm Hg 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

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.

Which sequence is the correct pathway 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 nurse working with a client in heart failure is explaining why the symptoms of the heart failure were not evident for a long period of time. When describing the Frank-Starling mechanism, the nurse will explain:

the relationship between venous return and stroke volume.

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

The electrical activity of the heart is recorded on the ECG. What does the T wave on the ECG represent?

Repolarization of the ventricles

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

Right-sided heart failure

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. What is the correct interpretation of this finding?

The client has increased pressure related to right-sided heart failure.

A nurse is reviewing an echocardiogram for a client with a congenital defect in the papillary muscles of the heart. Based on this result, which assessment should the nurse complete?

Auscultate for a murmur caused by the backward expulsion of blood through the atrioventricular valves.

Select the correct sequence of blood return to the heart.

Capillaries, venules, veins, right atrium

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 1 year ago. What does the nurse suspect is the problem?

Lymphedema

There are three main atrial pressure waves that occur during the cardiac cycle. What are the three main atrial pressure waves? Select all that apply.

a c v