NCLEX : Circulatory and Respiratory Systems

Study concepts, example questions & explanations for NCLEX

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Example Questions

Example Question #1 : Heart

Increased epinephrine would have what effect on stroke volume?

Possible Answers:

Stroke volume would decrease 

Stroke volume would stay the same

It would cause irregularities in stroke volume

Stroke volume would increase 

Correct answer:

Stroke volume would increase 

Explanation:

Increased epinephrine, released either by the adrenal medulla or by myocardial innervation, increases contractility in the heart, which in turn increases stroke volume. 

Example Question #2 : Circulatory System

Which of the following valves must blood pass through to go from the right atrium into the right ventricle?

Possible Answers:

The mitral valve

The tricuspid valve

The foramen ovale

The semilunar valve

Correct answer:

The tricuspid valve

Explanation:

Blood in the right atrium must pass through the tricuspid valve to enter the right ventricle. The mitral valve is between the left atrium and the left ventricle. The semilunar valves are located at the base of the aorta and the pulmonary trunk, also known as the aortic valve and pulmonary valve. The foramen ovale is a type of shunt that exists in the fetal heart. It's presence in an adult patient is a form of congenital heart defect.

Example Question #31 : Circulatory And Respiratory Systems

The S2 heart sound ("dub") is heard during what part of the cardiac cycle?

Possible Answers:

Systole; during the closing of the tricuspid and mitral valves

Diastole; during the closing of the aortic and pulmonary valves

Diastole; during the closing of the tricuspid and mitral valves

Systole; during the closing of the aortic and pulmonary valves

Correct answer:

Diastole; during the closing of the aortic and pulmonary valves

Explanation:

The S2 heart sound (sometimes referred to as the "dub" in "lub-dub") occurs in diastole, during the closing of the aortic and pulmonary valves. When pressure within the aorta and pulmonary arteries exceeds pressure within the heart, the cups of the valves fill with blood and snap shut, causing the "dub" sound.

Example Question #32 : Circulatory And Respiratory Systems

Depolarization is able to travel in a uniform wave through myocardium due to what physiological feature?

Possible Answers:

Striation

Gap junctions

T-tubules

Desmosomes

Correct answer:

Gap junctions

Explanation:

Depolarization is able to travel in a uniform wave through myocardium due to the presence of gap junctions. These junctions allow the depolarizing current to be transmitted directly from cell to cell in the heart. Striation in cardiac muscle is a feature of contraction, created by overlapping thick and thin contractile filaments. Desmosomes are strong fiber-like anchors between myocardial cells, and T-tubules, while an important part of depolarization, are not responsible for the rapid inter-cellular communication that occurs as a result of the presence of gap junctions. 

Example Question #33 : Circulatory And Respiratory Systems

Parasympathetic innervation of the heart is primarily controlled by what nerve?

Possible Answers:

The recurrent laryngeal nerve

The cardiac nerve

None of these is correct

The vagus nerve (CN X)

Correct answer:

The vagus nerve (CN X)

Explanation:

The vagus nerve provides the main parasympathetic innervation of the heart. The recurrent laryngeal nerve, a branch of the vagus nerve, innervates the majority of the intrinsic muscles of the larynx. The cardiac nerve is part of the sympathetic innervation of the heart.

Example Question #6 : Circulatory System

What coronary artery supplies left atrium and left ventricle?

Possible Answers:

The septal branches

The left coronary artery

The left circumflex artery

The posterior descending artery

Correct answer:

The left coronary artery

Explanation:

The majority of blood supply to the left atrium and left ventricle is provided by the  left coronary artery. The septal branches and left circumflex artery are smaller divisions of this main artery. The posterior descending artery supplies the posterior one-third of the interventricular septum.

Example Question #7 : Circulatory System

A nurse is performing an abdominal exam and notices a strong pulse in the abdomen just above the umbilicus. She is most likely palpating what blood vessel?

Possible Answers:

The abdominal aorta

The inferior mesenteric artery

The exterior iliac artery

The femoral artery

Correct answer:

The abdominal aorta

Explanation:

The nurse is most likely palpating the abdominal aorta. This vessel is large, generally 2.5-4 cm in diameter, and a strong pulse can often be felt on palpation. The femoral artery is also an area where a pulse may be felt, but it is only palpable in the mid-inguinal point of the inner thigh. The exterior iliac artery branches off of the abdominal aorta below the umbilicus, and the inferior mesenteric artery is a minor artery and is not generally palpable on examination.

Example Question #34 : Circulatory And Respiratory Systems

What is the formula for finding cardiac output (CO)?

Possible Answers:

Correct answer:

Explanation:

Cardiac output (CO) is the measure of the amount of blood that is able to circulate through the heart in one minute. It is found by multiplying the stroke volume times the heart rate, in beats per minute. The ejection fraction, another important measure of cardiac function, is not considered when calculating cardiac output.

Example Question #35 : Circulatory And Respiratory Systems

Oxygen-poor blood flows from the __________ to the __________.

Possible Answers:

pulmonary veins . . . left atrium

vena cava . . . right atrium

vena cava . . . left atrium

pulmonary arteries . . . right atrium

Correct answer:

vena cava . . . right atrium

Explanation:

Deoxygenated blood from the body flows through the superior and inferior vena cava into the right atrium of the heart. From there it enters the right ventricle, then is ejected into the lungs via the pulmonary arteries. The blood is oxygenated in the lungs, then flows through the pulmonary veins into the left atrium, then into the left ventricle to be pumped back out into the body.

Example Question #9 : Circulatory System

How does parasympathetic innervation affect the heart?

Possible Answers:

Increases heart rate and increases cardiac output

Slows heart rate and increases cardiac output

Slows heart rate and decreases cardiac output

Increases heart rate and decreases cardiac output

Correct answer:

Slows heart rate and decreases cardiac output

Explanation:

Sympathetic innervation will decrease the heart rate, which will automatically decrease the cardiac output 

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