A 52-year-old male suffered a myocardial infarction secondary to atherosclerosis and ischemia. Once oxygen returned to the damaged heart, reperfusion injury occurred as a result of:
Oxygenation of the cells
Free radical formation
Increased metabolic state
Lactic acid build-up
The Correct Answer is B
Choice A Reason:
Oxygenation of the cells is a necessary process during reperfusion, but it is not the direct cause of reperfusion injury. The injury occurs due to the sudden influx of oxygen, which leads to the formation of reactive oxygen species (ROS) or free radicals. These free radicals cause oxidative stress and damage to the myocardial cells.
Choice B Reason:
Free radical formation is the primary mechanism behind reperfusion injury. When blood flow is restored to the ischemic myocardium, the sudden reintroduction of oxygen leads to the production of free radicals. These free radicals cause significant oxidative damage to the cell membranes, proteins, and DNA, exacerbating the injury to the heart tissue.
Choice C Reason:
An increased metabolic state can occur during reperfusion as the cells attempt to recover from ischemia. However, it is not the direct cause of reperfusion injury. The primary issue is the oxidative stress caused by free radicals, not the metabolic changes themselves.
Choice D Reason:
Lactic acid build-up is a consequence of anaerobic metabolism during the ischemic period, not a cause of reperfusion injury. During ischemia, cells switch to anaerobic metabolism, leading to lactic acid accumulation. However, once oxygen is reintroduced, the focus shifts to the oxidative damage caused by free radicals rather than lactic acid.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Choice A Reason:
Beta2 agonists, such as terbutaline, are commonly used to manage premature labor. These drugs work by stimulating beta2 adrenergic receptors in the smooth muscles of the uterus, leading to relaxation and suppression of contractions. Therefore, questioning the use of a beta2 agonist in this scenario would not be appropriate.
Choice B Reason:
Anticholinergic drugs are not typically used to manage premature labor. They work by blocking the action of acetylcholine in the nervous system, which can lead to various effects such as reduced secretions and relaxation of smooth muscles. However, they are not specifically indicated for stopping uterine contractions, so questioning their use in this context is less relevant.
Choice C Reason:
This is the correct answer. Beta2 antagonists, also known as beta-blockers, work by blocking beta2 adrenergic receptors, which can lead to increased uterine contractions. Using a beta2 antagonist in a patient experiencing premature labor would be counterproductive and could exacerbate the condition. Therefore, it is appropriate to question the use of beta2 antagonists in this scenario.
Choice D Reason:
Alpha1 agonists are not typically used in the management of premature labor. These drugs stimulate alpha1 adrenergic receptors, leading to vasoconstriction and increased blood pressure. They do not have a direct effect on uterine contractions, so questioning their use in this context is less relevant.
Correct Answer is B
Explanation
Choice A Reason:
Vomiting is not a risk factor for a heart attack but rather a symptom that can occur during a heart attack. Risk factors are conditions or behaviors that increase the likelihood of developing a disease. Vomiting can be a sign of various conditions, including gastrointestinal issues or even a heart attack, but it does not contribute to the risk of having a heart attack.
Choice B Reason:
Hypertension, or high blood pressure, is a significant risk factor for heart attacks. It causes the heart to work harder than normal, leading to the thickening of the heart muscle and narrowing of the arteries. Over time, this increased workload can damage the arteries, making them more susceptible to blockages that can cause a heart attack. Managing blood pressure through lifestyle changes and medication is crucial in reducing the risk of heart attacks.
Choice C Reason:
Chest pain is a common symptom of a heart attack but not a risk factor. Risk factors are pre-existing conditions or behaviors that increase the likelihood of developing a disease. Chest pain, also known as angina, occurs when there is reduced blood flow to the heart muscle, often due to blockages in the coronary arteries. While chest pain indicates a potential heart problem, it is not a contributing factor to the development of a heart attack.
Choice D Reason:
Cell necrosis refers to the death of cells, which can occur during a heart attack when the blood supply to part of the heart muscle is blocked. This is a consequence of a heart attack rather than a risk factor. Risk factors are conditions or behaviors that increase the likelihood of developing a disease, whereas cell necrosis is a result of the disease process.
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