what are the three steps of the wave of excitation

HESI A2

HESI A2 Reading Comprehension V1 2024

1. What are the three steps of the 'wave of excitation'?

A. The discharge from the SA node, the peak ECG, and the excitement of the ventricle.
B. The excitement of the ventricle, the relaxing of the ventricle, and the systemic neural response.
C. The contraction of the atrium, the relaxation of the atrium, and the contraction of the ventricle.
D. The excitation of the atrium, the excitement of the ventricle, and the relaxing of the ventricle.

Correct answer: D

Rationale: The correct steps of the 'wave of excitation' are the excitation of the atrium, excitement of the ventricle, and relaxation of the ventricle. In the described process, the 'wave of excitation' starts with the discharge from the SA node, leading to the excitation of the atrium. Next, the peak ECG corresponds to the excitement of the ventricle, not its relaxation. Finally, the wave concludes with the relaxation of the ventricle, not its contraction. Therefore, choices A, B, and C are incorrect as they do not accurately describe the sequential steps of the 'wave of excitation' as presented in the extract.

2. What is the overall tone of the essay about A Short History of the CDC?

A. Appreciative.
B. Awestruck.
C. Somber.
D. Disheartened.

Correct answer: A

Rationale: The tone of the essay is appreciative, reflecting a recognition of the CDC's historical contributions to public health. The passage highlights the organization's evolution and its significant impact on disease control and prevention, suggesting a positive and respectful view of its work over the years, making A the correct choice.

3. Which of the following would be the best title for this passage?

A. Bicycles are better.
B. A ride through the history of bicycles.
C. Cycle your way to fitness.
D. The popularity of bicycles.

Correct answer: B

Rationale: The best title for this passage would be 'A ride through the history of bicycles' as it provides a comprehensive overview of the historical development of bicycles from their invention to modern times. Choice A, 'Bicycles are better,' is incorrect as it does not capture the essence of the passage, which focuses on the history and evolution of bicycles rather than their superiority. Choice C, 'Cycle your way to fitness,' is misleading as the passage does not primarily discuss the fitness aspect of cycling but instead focuses on the evolution of bicycle design. Choice D, 'The popularity of bicycles,' is too narrow as it only touches on one aspect mentioned briefly in the passage, while the passage covers a broader historical perspective.

4. Which of the following describes the purpose of the passage?

A. To describe the causes of cystic fibrosis
B. To explain how cystic fibrosis is passed down through families
C. To provide an overview of CF and how it is inherited
D. To review why some Americans have CF, but others do not

Correct answer: C

Rationale: The correct answer is C. The passage aims to provide an overview of cystic fibrosis (CF) and how it is inherited. It explains that CF is passed down through families due to a defective gene, detailing how this gene affects the body and who is most commonly affected by the disease. Choices A, B, and D are incorrect because the passage does not solely focus on describing the causes of CF, explaining how it is passed down through families, or reviewing why some Americans have CF while others do not. Instead, it provides a broader perspective on CF and its inheritance.

5. What can be inferred from the passage about Daylight Savings Time?

A. It is primarily used to save energy during certain months.
B. It was universally accepted upon its introduction.
C. The US government opposed the idea initially.
D. It was implemented to prevent jetlag.

Correct answer: A

Rationale: The correct answer is A: "It is primarily used to save energy during certain months." The passage clearly states that Daylight Savings Time was first put into practice by the German government in 1916 to save energy during the First World War. The US followed suit in 1918. This measure was unpopular initially, but the energy crisis in the 1970s led to making it a law. Choices B, C, and D are incorrect. Choice B is incorrect as the passage mentions that the British government initially refused the idea, and it was unpopular when first implemented. Choice C is incorrect as it was not the US but the British government that opposed the idea initially. Choice D is incorrect as Daylight Savings Time was not implemented to prevent jetlag, but rather to save energy and make better use of daylight hours.