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. The word 'massive' in line 4 is closest in meaning to?

A. Dense
B. Impressive
C. Huge
D. Unavoidable

Correct answer: C

Rationale: In the context of the passage, 'massive' is used to describe the size of the collision that formed the Moon, indicating something very large or huge. While 'dense' means closely compacted, 'impressive' means evoking admiration, 'huge' is the closest synonym to 'massive' in this context. 'Unavoidable' does not convey the same meaning as 'massive' in this sentence, making it incorrect.

3. What is the meaning of the word 'shifts' as used in the third paragraph?

A. Alterations
B. Stints
C. Removals
D. Transfers

Correct answer: A

Rationale: In this context, 'shifts' refers to changes or alterations in brain chemistry and electrophysiology. The word 'alterations' best captures the idea that significant changes are occurring in the brain. 'Stints' (choice B) refer to short periods of time or work, which is not the meaning intended here. 'Removals' (choice C) and 'transfers' (choice D) do not fit the context of the sentence and are not related to the changes happening in the brain as described in the extract.

4. What is the main idea of the passage about High Fructose Corn Syrup?

A. The passage discusses the potential health risks associated with consuming HFCS.
B. High fructose corn syrup may be contributing to obesity.
C. Manufacturing process of HFCS involves a chemical process.
D. Rats prefer high fructose corn syrup over other sweeteners.

Correct answer: B

Rationale: The main idea of the passage about High Fructose Corn Syrup is that it may be contributing to obesity in America. This is evident from the information provided in the extract, which discusses how HFCS has been linked to health issues, including obesity. Choice A is incorrect because the passage primarily focuses on the potential health risks associated with HFCS consumption, not just the examination by the American Medical Association. Choice C is irrelevant as it only talks about the manufacturing process of HFCS, which is not the central theme of the passage. Choice D is incorrect as it emphasizes the preference of rats for HFCS, which is a minor point compared to the potential impact on human health, particularly in relation to obesity.