Nursing Elites

1. What does the PR interval measure?

• A. Time it takes for the electrical impulse to travel from the atria to the ventricles
• B. Measurement of ventricular depolarization
• C. Duration of ventricular repolarization
• D. Segment representing the time between ventricular depolarization and repolarization

Correct answer: A

Rationale: The PR interval measures the time it takes for the electrical impulse to travel from the atria to the ventricles. It is crucial in diagnosing heart rhythm disorders, as abnormalities in this interval can indicate conduction abnormalities between the atria and ventricles. Choices B, C, and D are incorrect. The QRS complex represents ventricular depolarization, the QT interval represents the duration of ventricular repolarization, and the ST segment represents the time between ventricular depolarization and repolarization.

2. What is a condition where the heart beats too fast, reducing its ability to pump blood effectively?

• A. Tachycardia
• B. Bradycardia
• C. Arrhythmia
• D. Ventricular fibrillation

Correct answer: A

Rationale: Tachycardia is the correct answer because it is a condition characterized by a fast heart rate, which can decrease the heart's efficiency in pumping blood. Bradycardia, on the other hand, refers to a slow heart rate, which is the opposite of what is described in the question. Arrhythmia is a general term for any irregularity in the heart's rhythm, not necessarily specifically related to a fast heart rate. Ventricular fibrillation is a life-threatening arrhythmia where the heart's lower chambers quiver instead of pumping blood effectively, but it is not specifically characterized by a fast heart rate.

3. Which condition is characterized by the narrowing or blockage of arteries that supply blood to the heart by plaque?

• A. Coronary artery disease (CAD)
• B. Atherosclerosis
• C. Peripheral artery disease
• D. Congestive heart failure

Correct answer: A

Rationale: The correct answer is A, Coronary artery disease (CAD). CAD specifically refers to the condition where the arteries supplying blood to the heart become narrowed or blocked by plaque buildup. Choice B, Atherosclerosis, is a general term for the hardening and narrowing of arteries due to plaque buildup but does not specifically mention the heart. Choice C, Peripheral artery disease, involves narrowing of arteries that supply blood to areas other than the heart. Choice D, Congestive heart failure, is a condition where the heart is unable to pump blood effectively but is not primarily caused by narrowed or blocked arteries.

4. What is the condition where the lung collapses due to air leaking into the space between the lung and chest wall?

• A. Pneumothorax
• B. Pleural effusion
• C. Pulmonary fibrosis
• D. Lung cancer

Correct answer: A

Rationale: Pneumothorax is the correct answer. It is the collapse of a lung due to air leaking into the space between the lung and chest wall. This condition often requires emergency treatment. Choice B, Pleural effusion, is the buildup of excess fluid between the layers of the pleura outside the lung, not air. Choice C, Pulmonary fibrosis, is a lung disease characterized by scarring and thickening of lung tissue, not related to lung collapse. Choice D, Lung cancer, is the uncontrolled growth of abnormal cells in the lung, not directly causing lung collapse.

5. Which structure serves as the normal pacemaker of the heart?

• A. SA node
• B. AV node
• C. Purkinje fibers
• D. Atria

Correct answer: A

Rationale: The correct answer is the SA node. The sinoatrial (SA) node is known as the natural pacemaker of the heart as it generates electrical impulses initiating each heartbeat. The SA node is located in the right atrium and sets the rhythm and rate of the heartbeat. The AV node (choice B) is responsible for delaying the electrical impulse to allow the atria to contract before the ventricles. Purkinje fibers (choice C) are specialized cardiac fibers responsible for the rapid conduction of impulses to the myocardial cells, and the atria (choice D) are the upper chambers of the heart involved in receiving blood from the veins.

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