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. What test measures the electrical activity of the heart over a 24- or 48-hour period?

• A. Holter monitor
• B. Electrocardiogram
• C. Stress test
• D. Chest X-ray

Correct answer: A

Rationale: The correct answer is A, Holter monitor. A Holter monitor is a portable device that continuously records the heart's electrical activity over 24 to 48 hours, aiding in the diagnosis of arrhythmias and other heart conditions. Choice B, an Electrocardiogram, provides a snapshot of the heart's electrical activity at a specific point in time, not over an extended period like a Holter monitor. Choice C, a Stress test, measures how the heart responds to physical activity and is not used for continuous monitoring of electrical activity. Choice D, a Chest X-ray, is used to visualize the structures of the chest, not to measure the heart's electrical activity.

3. 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.

4. What condition involves a weakened and bulging aorta, the main artery in the body, potentially leading to rupture?

• A. Aortic aneurysm
• B. Arterial stenosis
• C. Pulmonary embolism
• D. Deep vein thrombosis

Correct answer: A

Rationale: An aortic aneurysm is a condition characterized by the weakening and bulging of the aorta, the body's main artery. If left untreated, this bulging may lead to a rupture, causing severe complications. Arterial stenosis refers to the narrowing of an artery, not the weakening and bulging seen in an aortic aneurysm. Pulmonary embolism involves a blockage in the pulmonary artery, which is different from the weakening and bulging in an aortic aneurysm. Deep vein thrombosis is the formation of a blood clot in a deep vein, not related to the condition described in the question.

5. This is a branch of the left coronary arteries which supplies the LEFT ATRIUM, posterior lateral surface of the left ventricle.

• A. Right coronary artery
• B. Left circumflex artery
• C. Left anterior descending artery
• D. Posterior descending artery

Correct answer: B

Rationale: The correct answer is B, Left circumflex artery. The circumflex artery is a branch of the left coronary artery that supplies blood to the left atrium and the lateral wall of the left ventricle. Choice A, the Right coronary artery, does not supply the mentioned areas. Choice C, the Left anterior descending artery, supplies the anterior wall of the left ventricle. Choice D, the Posterior descending artery, is a branch of the right coronary artery and supplies the inferior wall of the left ventricle and the posterior septum.

Similar Questions