Many of the clinical manifestations for acute stress are attributed to activation of the sympathetic nervous system and are mediated by:
Norepinephrine
Cortisol
ACTH
Glucagon
The Correct Answer is A
Choice A Reason:
Norepinephrine is a key neurotransmitter released by the sympathetic nervous system during the “fight-or-flight” response. It plays a crucial role in preparing the body to respond to stress by increasing heart rate, blood pressure, and blood flow to muscles, as well as dilating the airways. These physiological changes are essential for coping with acute stress.
Choice B Reason:
Cortisol is a hormone released by the adrenal glands in response to stress, but it is primarily associated with the hypothalamic-pituitary-adrenal (HPA) axis rather than the sympathetic nervous system. While cortisol contributes to the body’s overall stress response by increasing blood sugar levels and suppressing the immune system, it is not the primary mediator of the acute “fight-or-flight” response.
Choice C Reason:
ACTH (adrenocorticotropic hormone) is a hormone produced by the pituitary gland that stimulates the adrenal glands to release cortisol. It is part of the HPA axis and plays a role in the body’s long-term stress response, but it is not directly involved in the immediate activation of the sympathetic nervous system.
Choice D Reason:
Glucagon is a hormone produced by the pancreas that raises blood glucose levels by promoting the breakdown of glycogen to glucose in the liver. While it can be involved in the body’s response to stress by ensuring an adequate supply of glucose, it is not a primary mediator of the acute stress response mediated by the sympathetic nervous system.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Choice A: Alkalosis
Alkalosis refers to a condition where the blood pH is higher than the normal range (above 7.45). In this case, the pH is 7.25, which indicates an acidic environment rather than an alkaline one. Therefore, alkalosis is not the correct answer.
Choice B: Respiratory
Respiratory acidosis or alkalosis is determined by the levels of PaCO2. In respiratory acidosis, PaCO2 is elevated, while in respiratory alkalosis, PaCO2 is decreased. Here, the PaCO2 is 20 mm Hg, which is below the normal range, indicating a respiratory component. However, the primary issue is not respiratory because the HCO3- is also significantly low, pointing towards a metabolic cause.
Choice C: Metabolic
Metabolic acidosis is characterized by a low pH and a low HCO3- level. In this case, the pH is 7.25, and the HCO3- is 10 mEq/L, both of which are below the normal ranges. This indicates that the primary acid-base imbalance is metabolic acidosis.
Choice D: Acidosis
Acidosis refers to a condition where the blood pH is lower than the normal range (below 7.35). The given pH of 7.25 confirms that the patient is experiencing acidosis. However, this choice alone does not specify whether it is metabolic or respiratory acidosis.
Choice E: With Compensation (Being Compensated)
Compensation refers to the body’s attempt to return the pH to normal by adjusting the levels of PaCO2 or HCO3-. In this case, the low PaCO2 suggests that there is a respiratory compensation for the metabolic acidosis. However, the primary imbalance remains metabolic acidosis.
Correct Answer is B
Explanation
Choice A Reason:
Increased neuromuscular excitability is not typically associated with respiratory acidosis. Instead, respiratory acidosis can lead to symptoms such as confusion, fatigue, and shortness of breath due to the buildup of carbon dioxide in the blood. Neuromuscular excitability is more commonly associated with conditions like hypocalcemia.
Choice B Reason:
This is the correct answer. Respiratory acidosis occurs when the lungs cannot remove enough carbon dioxide (CO2) from the body, leading to an accumulation of CO2 in the blood. This increase in CO2 results in the formation of carbonic acid, which lowers the pH of the blood. The elevated levels of carbonic acid are a hallmark of respiratory acidosis.
Choice C Reason:
Increased pH is not associated with respiratory acidosis. In fact, respiratory acidosis is characterized by a decrease in blood pH due to the accumulation of carbon dioxide and the subsequent increase in carbonic acid. Therefore, this choice is incorrect.
Choice D Reason:
Hypokalemia, or low potassium levels, is not typically associated with respiratory acidosis. Instead, respiratory acidosis can sometimes lead to hyperkalemia (high potassium levels) due to the shift of potassium out of cells in response to the acidotic state. Therefore, this choice is incorrect.
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