Nursing Elites

1. Which structure serves as the major chemoreceptor of the heart?

• A. Carotid body
• B. Aortic body
• C. Vagus nerve
• D. SA node

Correct answer: A

Rationale: The correct answer is A, the carotid body. The carotid body is the major chemoreceptor of the heart responsible for detecting changes in blood oxygen, carbon dioxide, and pH levels. This specialized structure helps regulate the cardiovascular system's response to maintain appropriate oxygen levels in the blood. Choices B, C, and D are incorrect as they are not directly involved in chemoreception in the heart. The aortic body is primarily involved in blood pressure regulation, the vagus nerve is a cranial nerve responsible for parasympathetic innervation, and the SA node is known as the heart's natural pacemaker.

2. During which process does coronary artery blood flow to the myocardium occur during diastole, when coronary vascular resistance is reduced?

• A. Coronary perfusion pressure
• B. Coronary vascular resistance
• C. Diastolic filling
• D. Ventricular ejection

Correct answer: A

Rationale: The correct answer is A: Coronary perfusion pressure. Coronary perfusion pressure refers to the process of coronary artery blood flow to the myocardium during diastole when coronary vascular resistance is reduced. This process ensures that the myocardium receives sufficient oxygen and nutrients for proper functioning. Choice B, Coronary vascular resistance, is the opposite of what is described in the question. During coronary perfusion, resistance is reduced to enhance blood flow. Choices C and D, Diastolic filling and Ventricular ejection, do not directly relate to the process of coronary artery blood flow during diastole.

3. What term describes the phenomenon wherein decreased BP causes a reflex SNS response with increased pulse, increased contractility, and vasoconstriction; and increased BP causes reflex vagal responses resulting in decreased heart rate and passive vasodilation in the systemic arterioles?

• A. Baroreflex
• B. Cheyne-Stokes breathing
• C. Frank-Starling Law
• D. Starling reflex

Correct answer: A

Rationale: The correct answer is A: Baroreflex. The Baroreflex is a mechanism by which the body maintains blood pressure homeostasis through reflexive adjustments in heart rate and vascular tone. Choice B, Cheyne-Stokes breathing, is a pattern of breathing characterized by progressively deeper and sometimes faster breathing, followed by a gradual decrease that results in a temporary stop in breathing. Choices C and D, Frank-Starling Law and Starling reflex, are related to the intrinsic ability of the heart to adjust its output based on venous return, not specifically regulating blood pressure through reflex adjustments in heart rate and vascular tone as seen in the described phenomenon.

4. What procedure is used to remove fluid from the pleural space to help a patient breathe more easily?

• A. Thoracentesis
• B. Bronchoscopy
• C. Echocardiogram
• D. CT scan

Correct answer: A

Rationale: Thoracentesis is the correct answer. It is a procedure where a needle is inserted into the pleural space to drain fluid, relieving pressure and helping the patient breathe more easily. Bronchoscopy (choice B) is a procedure used to examine the airways, not to drain fluid. An echocardiogram (choice C) is an imaging test to assess the heart's structure and function, not related to draining pleural fluid. A CT scan (choice D) is a cross-sectional imaging test that provides detailed pictures of the inside of the body, not used for draining pleural fluid.

5. What is the term that describes the inability of cardiac cells to respond to a new stimulus while they are still in contraction from a previous stimulus?

• A. Refractoriness
• B. Excitability
• C. Contractility
• D. Automaticity

Correct answer: A

Rationale: Refractoriness is the correct term to describe the inability of cardiac cells to respond to a new stimulus while they are still in contraction from a previous stimulus. This period is essential for the heart to complete its contraction and relaxation phases without interference. Excitability refers to the ability of cells to respond to stimuli, not the inability to respond. Contractility is the force of cardiac muscle contraction, and automaticity is the ability of cardiac cells to generate electrical impulses spontaneously, which are not relevant to the described scenario.

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