Question 1

As part of presurgical teaching for patients who are about to undergo a coronary artery bypass graft, a nurse is performing an education session with a group of surgical candidates. Which of the following teaching points best conveys an aspect of the human circulatory system?

Accepted Answer

There is a large variation between the higher pressure in the systemic circulatory system and arteries and the lower pressure in the pulmonary system and veins. Approximately 8% of the blood supply is in the heart at any given time. Blood pressure and blood volume are inversely proportionate. The body is able to accommodate short-term differences in left-sided and right-sided output.

Question 2

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

Accepted Answer

During a change in body position, blood is rapidly relocated from the central circulation (when the patient is recumbent) to the lower extremities (when the patient stands up).
This results in a temporary drop in blood pressure known as postural hypotension and reflects the redistribution of blood in the body.

Question 3

Which of the following statements most accurately captures a principle of blood flow?

Accepted Answer

Doubling the radius of a vessel is associated with a fourth-power increase in flow, provided pressure remains constant. Blood flow is primarily a function of blood pressure, resistance, and viscosity. The small size of capillaries is associated with quite slow velocity, given their large total combined cross-sectional area. Smaller cross-sectional area is associated with greater velocity.

Question 4

A 72-year-old female has been told by her physician that she has a new heart murmur that requires her to go visit a cardiologist. Upon examination, the cardiologist informs the patient that she has aortic stenosis. After the cardiologist has left the room, the patient asks, "What caused this [aortic stenosis] to happen now?" The clinic nurse responds,

Accepted Answer

Heart murmur results from turbulent flow through a diseased heart valve that may be too narrow, too stiff, or too floppy. This turbulent flow causes a vibration called a murmur.

Question 5

A physician is teaching a group of medical students about the physiological basis for damage to the circulatory and neurological systems that can accompany hypotension. Which of the following responses by a student would warrant correction by the physician?

Accepted Answer

Tension and vessel wall thickness are inversely proportionate, in that thinner blood vessels have greater tension and vice versa. Answer choices A, B, and C all express the correct inverse relationship between tension and wall thickness.

Question 6

During an automobile accident where the patient is bleeding heavily, which vascular component is the most distensible and can store large quantities of blood that can be returned to the circulation at this time of need?

Accepted Answer

Compliance refers to the total quantity of blood that can be stored in a given portion of the circulation for each mm Hg rise in pressure. The most distensible of all vessels are the veins, which can increase their volume with only slight changes in pressure. This allows the veins to function as a reservoir for storing large quantities of blood that can be returned to the circulation when it is needed. The liver, pancreas, and kidneys are not vascular components.

Question 7

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?

Accepted Answer

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.

Question 8

A pathologist is examining histological (tissue) samples from a client with an autoimmune disease. Which of the following characteristics of muscle samples would signal the pathologist that the samples are cardiac rather than skeletal muscle?

Accepted Answer

Cardiac cells have a less clearly defined sarcoplasmic reticulum than do skeletal muscles. They also have intercalated disks and large, numerous mitochondria. Both types of muscles are striated and composed of sarcomeres.

Question 9

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?

Accepted Answer

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.

Question 10

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?

Accepted Answer

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.

Question 11

A patient is experiencing impaired circulation secondary to increased systemic arterial pressure. Which of the following statements is the most relevant phenomenon?

Accepted Answer

Increased pressure in the aorta and other arteries constitutes a greater amount of afterload work. This situation is not indicative of increased preload or impaired contractility. Systolic impairment is not a recognized characterization of inadequate cardiac performance.

Question 12

In the ICU, the nurse hears an emergency cardiac monitor go off. The nurse looks at the telemetry and notices the patient has gone into ventricular tachycardia. The nurse will likely assess for signs/symptoms of

Accepted Answer

One of the dangers of ventricular tachycardia is a reduction in cardiac output because the heart does not have time to fill adequately.

Question 13

A nurse is using a stethoscope and blood pressure cuff to manually measure a client's blood pressure. The nurse knows that which of the following facts related to blood flow underlies the ability to hear blood pressure by auscultation (listening)?

Accepted Answer

The pressure pulsations that accompany intermittent blood ejection from the ventricles cause sounds that are audible when measuring blood pressure and palpable at pulse sites. Friction, muscle movement, and turbulent blood flow do not account for the pressure pulsations.

Question 14

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

Accepted Answer

Normal right atrial pressure is around 0 mm Hg, or atmospheric pressure. Right atrial pressure does not have a direct influence on stroke volume or pulse pressure.

Question 15

A patient arrived at the emergency department 2 days after the development of "chest pressure" and "tightness" was treated with antacids thinking it was indigestion. His enzymes show a massive myocardial infarction (MI). Following angioplasty, the patient asks why so much muscle was damaged if only one vessel was blocked, the left circumflex. The nurse responds,

Accepted Answer

Hyperemia cannot occur when the arteries that supply the capillary beds are narrowed. For example, if a major coronary artery becomes occluded, the opening of channels supplied by that vessel cannot restore blood flow.

Question 16

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

Accepted Answer

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.

Question 17

Which of the following individuals is most likely to be experiencing vasodilation?

Accepted Answer

Angiotensin is a potent vasoconstrictor, and medications that block this induce vasodilation. Epinephrine is also a vasoconstrictor. Histamine is a vasodilator, so antihistamine medications are likely to induce vasoconstriction. Serotonin is a vasoconstrictor, so medications that block its reuptake and increase free levels are apt to promote vasoconstriction.

Question 18

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

Accepted Answer

The glomerular capillaries in the kidneys have small openings called fenestrations that pass directly through the middle of the endothelial cells. These allow large amounts of small molecular and ionic substances to filter through the glomeruli without having to pass through the clefts between the endothelial cells.

Question 19

A 51-year-old patient with a history of alcohol abuse and liver disease has low serum levels of albumin and presents with ascites (excess fluid in his peritoneal space) and jaundice. A health care professional would recognize that which of the following processes is most likely underlying his health problems?

Accepted Answer

Deficits of plasma proteins like albumin result in insufficient amounts of fluid being absorbed into the capillary circulation by osmotic pressure. It is not a result of hydrostatic pressure, hypertension, or the effects of gravity.

Question 20

While intubated for surgery, a patient has inadvertently had his vagus nerve stimulated. What effect would the surgical team expect to observe?

Accepted Answer

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.

Quiz 28: Disorders of Cardiac Conduction and Rhythm