The nurse in the emergency department is caring for a client with a temperature of 39°C (102.5°F), productive cough, chills, shortness of breath, and malaise. Which diagnostic test should the nurse expect to prepare the client for? (Select all that apply.)

Correct Answer: A

Rationale: Chest x-ray (A), sputum culture, and arterial blood gases (A, B, D) diagnose pneumonia per the document. X-ray (A) confirms consolidation (e.g., lobar opacity). Sputum (B) identifies pathogens (e.g., S. pneumoniae), ABGs (D) assess hypoxemia (PaOâ‚‚ <80 mmHg). Polysomnography (C) tests sleep apnea, not pneumonia. MRI is rare here. A's priority visualizing lung infiltrates drives diagnosis, distinguishing it as the key test.

Correct Answer: B

Rationale: Internal respiration is the exchange of gases oxygen from blood to tissues, carbon dioxide from tissues to blood occurring at the cellular level via diffusion across capillaries. ATP production is cellular respiration's outcome, not the exchange itself. Alveolar-blood exchange is external respiration, not internal. Breathing from atmosphere to alveoli is ventilation, not respiration's tissue phase. This process sustains metabolism, delivering oxygen for energy and removing CO2 waste, distinct from lung-based external respiration, a vital concept in understanding systemic oxygen transport and tissue oxygenation in physiology.

Correct Answer: D

Rationale: Pericardial fluid, a serous secretion between the pericardium's parietal and visceral (epicardium) layers, reduces friction as the heart beats, ensuring smooth motion within the sac. Synovial fluid lubricates joints, not the heart. The endocardium lines heart chambers, not reducing external friction. Pleural fluid lubricates lung pleura, not the pericardium. This fluid's role about 15-50 mL prevents adhesion during cardiac cycles, a vital mechanism for uninterrupted pumping, central to cardiac physiology and relevant in pericardial effusion where excess fluid disrupts function.

Correct Answer: C

Rationale: The pulmonary semilunar valve prevents blood from flowing back into the right ventricle, closing after systole as pulmonary artery pressure exceeds ventricular pressure, ensuring one-way flow to the lungs. The tricuspid valve stops backflow into the right atrium, not ventricle. The bicuspid (mitral) serves the left side. The aortic semilunar valve guards the left ventricle. This valve's role in pulmonary circulation is crucial, maintaining forward flow, key in right heart dynamics and conditions like pulmonary regurgitation affecting lung perfusion.

Correct Answer: D

Rationale: The second heart sound ('dupp') occurs when semilunar valves (aortic and pulmonary) close, marking the end of ventricular systole as ventricular pressure drops below arterial pressure, halting ejection. Valvular stenosis is a condition, not an event. Semilunar valves opening starts systole, tied to the first sound ('lub') with AV valve closure. AV closing precedes systole, not the second sound. This 'dupp,' sharper and higher-pitched, reflects elastic recoil of closed valves, a key auscultatory marker in the cardiac cycle, critical for timing and diagnosing valve issues like regurgitation.