ATI LPN
Questions for Respiratory System Questions
Question 1 of 5
Which of the following correctly lists the sequence of structures that a cardiac action potential follows in order to excite normal contraction of the heart?
Correct Answer: D
Rationale: The cardiac action potential follows: SA node (pacemaker, initiates), AV node (delays signal), bundle of His (transmits to ventricles), Purkinje fibers (spreads to ventricular myocardium), driving normal contraction. Other sequences disrupt this flow e.g., starting with Purkinje or misordering AV node delays atrial-ventricular timing. This precise path, from SA node atop the right atrium to Purkinje's ventricular reach, ensures atria contract before ventricles, optimizing filling and ejection, a fundamental rhythm in cardiac physiology, disrupted in arrhythmias like bundle branch block.
Question 2 of 5
Which of the following is another name for the visceral layer of the pericardium?
Correct Answer: B
Rationale: The epicardium is another name for the visceral pericardium, the serous layer adhering to the heart's surface, distinct from the parietal pericardium and fibrous outer sac. Endocardium lines chambers, myocardium is muscle, fibrous pericardium is external. This synonym reflects its pericardial role, key in friction reduction, critical in epicardial pathology like inflammation, a precise layer nomenclature.
Question 3 of 5
The organs of the respiratory system include all the following EXCEPT:
Correct Answer: D
Rationale: Body tissues (D) are not respiratory system organs, per the key they're served by it. The nose (A) filters/warms air (e.g., 10000 L/day). The trachea (B) conducts air (cartilage-supported). Lungs (C) exchange gases (300 million alveoli). The respiratory system nose, pharynx, larynx, trachea, bronchi, lungs delivers Oâ‚‚ and removes COâ‚‚, per anatomy texts. Tissues (e.g., muscles, liver) use Oâ‚‚ but aren't part of this system; they're the endpoint of internal respiration. This excludes D, unlike A's entry point, B's conduit, or C's gas exchange role tissues rely on, but don't constitute, the respiratory apparatus.
Question 4 of 5
A client who develops acute respiratory distress syndrome (ARDS) is exhibiting hypoxemia unresponsive to oxygen therapy. In explaining the client's condition to the family, the nurse would incorporate which concept?
Correct Answer: A
Rationale: ARDS shunts blood past non-ventilated alveoli (A), per document (1). Diffuse alveolar damage (e.g., sepsis) fills alveoli with exudate (100-200 mL), halting ventilation (V/Q = 0). Oâ‚‚ therapy fails PaOâ‚‚ <60 mmHg despite FiOâ‚‚ 1.0 unlike COPD's air trapping (B). Surfactant decreases (C false), and secretions (D) are secondary. A's shunting 50% blood bypass explains refractory hypoxemia, distinguishing it from B's obstruction or C's reversal.
Question 5 of 5
The nurse caring for a client diagnosed with acute respiratory distress syndrome (ARDS) should consider that in this client, impaired gas exchange is mostly likely related to which factor?
Correct Answer: C
Rationale: ARDS impairs gas exchange via shunting past non-ventilated alveoli (C), per document (3). Exudate (e.g., 200 mL) from injury (e.g., sepsis) floods alveoli, dropping ventilation (V/Q = 0), causing hypoxemia (PaOâ‚‚ <50 mmHg). Air trapping (A) is COPD. Fluid accumulation (B) contributes, but shunting's the mechanism. Excess AAT (D) is irrelevant. C's bypass 50% blood unoxygenated explains Oâ‚‚ failure, unlike A's obstruction.