NCLEX : Circulatory and Respiratory Systems

Study concepts, example questions & explanations for NCLEX

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Example Questions

Example Question #41 : Circulatory And Respiratory Systems

Which of the following causes the S1 heart sound (lub)?

Possible Answers:

The closing of the aortic and pulmonary valves

The closing of the tricuspid and mitral (AV) valves

The opening of the aortic and pulmonary valves

The opening of the tricuspid and mitral (AV) valves

Correct answer:

The closing of the tricuspid and mitral (AV) valves

Explanation:

The S1 heart sound (sometimes referred to as "lub") is caused by the sudden snapping-shut of the tricuspid and mitral valves during systole, when the heart contracts and tension on the chordae tendinae is released. No sound is produced on the opening of these or any other valves in the heart.

Example Question #42 : Circulatory And Respiratory Systems

The contraction rate is set in what area of the heart?

Possible Answers:

The sinoatrial node

The bundle of His

The Purkinje fibers

The atrioventricular node

Correct answer:

The sinoatrial node

Explanation:

The contraction rate for the heart is set by the cells of the sinoatrial node, also known as the pacemaker cells of the heart. These cells have membranes that are especially permeable to ions, and are able to depolarize on their own at a rate of 70-100 beats per minute. All the other areas listed do have their own spontaneous contractility, but their rates are slower than that of the sinoatrial node. Thus, the sinoatrial node is the pacemaker in a healthy heart.

Example Question #13 : Circulatory System

Which of the following is the proper unit of measurement for blood pressure?

Possible Answers:

IU

Correct answer:

Explanation:

The proper unit when recording a patient's blood pressure is mmHg, or millimeter of mercury. This is derived from a historical measurement of how many millimeters of mercury in a mercury manometer were able to be elevated by a particular pressure. Due to it's toxicity,  are longer used in medical equipment, though the  unit remains in use.

Example Question #43 : Circulatory And Respiratory Systems

A patient has a 49 year history of hypertension. Which part of the heart would be most enlarged on echocardiogram?

Possible Answers:

Left atrium

Left ventricle

Pulmonary artery

Right atrium

Right ventricle

Correct answer:

Left ventricle

Explanation:

The left ventricle is the most commonly enlarged heart structure seen in chronic hypertension. The left ventricle must overcome the afterload of the arterial system by becoming hypertrophied. As a result, the heart gets remodeled to overcome the systemic high blood pressures. The left ventricle directly pumps blood from the heart to the systemic circuit.

Example Question #1 : Lymphatic System

What organ of the lymphatic system is the site of T-cell maturation?

Possible Answers:

The thymus

The spleen

The lymph nodes

The cisterna chyli

Correct answer:

The thymus

Explanation:

T-cell maturation occurs in the thymus, a small organ located in the upper part of the mediastinum, between the heart and the sternum. Mature T cells then may either circulate in the lymph or blood or reside in lymph nodes. The spleen is not a site of T cell maturation, though it does have other important immune functions, such as the production of antibodies and the removal of antibody-coated pathogens. The cisterna chyli is a part of the lymphatic system that is involved in lipid digestion.

Example Question #44 : Circulatory And Respiratory Systems

Digestive fat is absorbed through what specialized lymphatic vessels of the small intestine?

Possible Answers:

The cisterna chyli

Villi

Lacteals

Microvilli

Correct answer:

Lacteals

Explanation:

Dietary fat is absorbed via lacteals, small lymph vessels contained within the body of the intestinal villi. Microvilli, tiny projections covering the surface of the villi, help with the absorption of minerals, vitamins, and other micronutrients. The cisterna chyli is a dilated pouch at the lower end of the thoracic duct that serves as a collection point for fatty chyle from the intestinal lacteals.

Example Question #3 : Lymphatic System

Which of the following is not a function of the lymphatic system?

Possible Answers:

Absorption and transportation of dietary fats

Lymphocyte transport and activation

Secondary gas exchange

Draining of interstitial fluid from tissues

Correct answer:

Secondary gas exchange

Explanation:

The lymphatic system has several roles in the body, including drainage of interstitial fluid from tissues, transportation and activation of lymphocytes, and absorption and transportation of dietary fats. Red blood cells, however, are unable to enter lymph vessels, and so the lymphatic system does not participate in any type of gas exchange.

Example Question #45 : Circulatory And Respiratory Systems

When drawing blood, the client tells the nurse that she is a universal recipient. The nurse knows this to mean that the patient has which type of blood?
Possible Answers:
AB negative
A positive
AB positive
O negative
Correct answer: AB positive
Explanation: AB positive is a universal recipient, meaning a patient with AB positive type blood can receive a blood transfusion using any type of blood.

Example Question #46 : Circulatory And Respiratory Systems

Every heme group in hemoglobin encloses an atom of what element?

Possible Answers:

Iron

Copper

Chromium

Magnesium

Correct answer:

Iron

Explanation:

Each heme group in hemoglobin encloses a single iron atom in the center of a protoporphyrin, a tetrapyrrol composed of four pyrrole rings linked together by four methyl groups, two vinyl groups, a methane bridge, and two propinoic acid side chains.

Example Question #47 : Circulatory And Respiratory Systems

What is the average lifespan of an erythrocyte?

Possible Answers:

4 months

3 months

6 months

6 weeks

Correct answer:

4 months

Explanation:

The average lifespan of a red blood cell is 4 months, after which it is phagocytosed by macrophages the spleen, liver, or lymph nodes. White blood cells, on the other hand, live for only about 3-4 days.

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