What is a key stage of the oxygen cycle?

Correct Answer: A

Rationale: Rationale: The correct answer is A) Photosynthesis. In the oxygen cycle, photosynthesis is a key stage where plants convert carbon dioxide into oxygen using sunlight, water, and chlorophyll. This process is crucial for replenishing the atmospheric oxygen that is essential for the survival of all aerobic organisms, including humans. Option B) Nitrogen fixation is incorrect because it is a process by which certain bacteria convert atmospheric nitrogen into a form usable by plants, not directly related to the production of oxygen in the oxygen cycle. Option C) Sulfur deposition is incorrect as it refers to the process where sulfur compounds are deposited back onto the Earth's surface, mainly through precipitation, and does not play a significant role in the oxygen cycle. Option D) Carbon sequestration is also incorrect because it involves capturing and storing carbon dioxide to reduce its concentration in the atmosphere, which is important for mitigating climate change but does not directly contribute to the production of oxygen in the oxygen cycle. Understanding the oxygen cycle is essential for students studying biology, environmental science, or healthcare fields like nursing. Knowing how oxygen is produced and cycled through the environment helps students grasp the interconnectedness of living organisms and the environment. It also highlights the importance of plant life in maintaining the balance of gases in the atmosphere, which directly impacts human health and well-being.

Correct Answer: A

Rationale: In the context of oxygen therapy, understanding the implications of electrolyte imbalances like hypokalemia is crucial for safe and effective patient care. In the given scenario, the correct answer is A) Cardiac arrhythmias. Potassium plays a vital role in cardiac muscle function, and low levels can lead to dangerous arrhythmias, potentially resulting in cardiac arrest. Therefore, assessing for cardiac rhythm abnormalities takes precedence as it is a life-threatening complication that requires immediate intervention. Option B) Muscle weakness, though a symptom of hypokalemia, is not as immediately life-threatening as cardiac arrhythmias. While it is important to monitor for muscle weakness, addressing cardiac issues is of higher priority. Option C) Respiratory distress is not directly linked to hypokalemia. Although respiratory muscles can be affected by severe electrolyte imbalances, the primary concern with low potassium levels is the impact on cardiac function. Option D) Nausea is a common but less critical symptom of hypokalemia. While it can indicate electrolyte imbalances, it does not pose the immediate danger that cardiac arrhythmias do. Educationally, this question highlights the need for nurses to recognize the significance of electrolyte imbalances and prioritize assessments based on the potential severity of complications. Understanding the relationship between potassium levels and cardiac function is essential for providing safe and competent care to patients, especially those receiving oxygen therapy where optimal oxygenation and cardiovascular function are paramount.

Correct Answer: C

Rationale: In the scenario of a woman with preeclampsia experiencing a seizure, the priority action for the nurse is to administer oxygen by mask (Option C). This is the correct answer because during a seizure, the body's demand for oxygen increases significantly. Providing oxygen by mask ensures that the patient receives an adequate supply of oxygen to prevent hypoxia and maintain oxygenation to vital organs, including the brain. Inserting an oral airway (Option A) is not the priority in this situation because maintaining oxygenation is more critical during a seizure. An oral airway may be considered once the seizure has subsided to help maintain a clear airway. Suctioning the mouth to prevent aspiration (Option B) is also not the priority during an active seizure. While preventing aspiration is important, ensuring oxygenation takes precedence in this emergency situation. Calling the physician immediately (Option D) is not the priority action during an active seizure. The immediate focus should be on providing essential care to the patient to stabilize their condition. Once the patient is stable, the nurse can involve the physician as needed. Educationally, this question highlights the importance of prioritizing care during emergency situations, such as seizures in patients with preeclampsia. Nurses must be able to quickly assess and intervene to address the most critical needs of the patient to ensure positive outcomes. Understanding the rationale behind the priority actions in such scenarios is essential for providing safe and effective care in clinical practice.

Correct Answer: B

Rationale: In the context of a client with acute respiratory distress syndrome (ARDS), the priority nursing diagnosis is Impaired Spontaneous Ventilation (B). This is because ARDS is characterized by severe respiratory compromise, necessitating immediate interventions to maintain adequate oxygenation. Impaired Spontaneous Ventilation directly addresses the primary issue of respiratory distress in ARDS, making it crucial to prioritize this nursing diagnosis. The other options are not the priority in this scenario because: A) Risk for Infection: While infection is a potential complication in ARDS due to compromised lung function, it is secondary to the immediate threat of inadequate oxygenation. Treating the underlying ventilation issue takes precedence over preventing potential future infections. C) Risk for Acute Confusion: While patients with ARDS may experience altered mental status due to hypoxemia, addressing their respiratory distress is more critical in the immediate term to ensure adequate oxygen supply to vital organs. D) Decreased Cardiac Output: While ARDS can lead to systemic complications, such as decreased cardiac output, addressing the primary respiratory issue is paramount to improve oxygenation and prevent further deterioration. In an educational context, understanding the priority nursing diagnosis in ARDS highlights the significance of timely interventions in managing respiratory emergencies. Nurses need to prioritize interventions that directly address the most life-threatening issues to optimize patient outcomes. By focusing on Impaired Spontaneous Ventilation as the priority diagnosis in ARDS, nurses can effectively target the critical need for oxygenation support in these high-acuity situations.

Correct Answer: C

Rationale: In the context of a client with COPD secondary to emphysema, the correct answer is option C) Barrel chest. This is because a barrel chest is a classic physical manifestation seen in individuals with emphysema due to the chronic air trapping and lung hyperinflation that occurs in this condition. The overinflation of the lungs leads to a characteristic increase in the anteroposterior diameter of the chest, resulting in a barrel-shaped appearance. Option A) Tachycardia is not typically a direct clinical manifestation of emphysema or COPD. While individuals with COPD may experience tachycardia as a result of hypoxia or exacerbations, it is not a specific hallmark of emphysema. Option B) Cough is a common symptom in COPD; however, it is not specific to emphysema and can be present in various respiratory conditions. Option D) Wheezing is more commonly associated with asthma or bronchospasm rather than emphysema. Wheezing is caused by narrowing of the airways, which is not the primary pathology in emphysema. Understanding the characteristic clinical manifestations of COPD, such as a barrel chest in emphysema, is crucial for nurses caring for these patients. Recognizing these signs aids in accurate assessment, diagnosis, and management of COPD, ultimately promoting optimal patient outcomes. By linking theoretical knowledge with clinical practice, nurses can provide comprehensive care and support to individuals with COPD.