A client with pneumonia is prescribed 100% oxygen. Which type of oxygen delivery device should the nurse use?

Correct Answer: D

Rationale: A nonrebreather mask (D) delivers 100% oxygen (FiOâ‚‚ 0.9-1.0) for severe pneumonia hypoxemia (PaOâ‚‚ <60 mmHg), per nursing texts. Simple mask (A) maxes at 60%. Venturi (B) adjusts FiOâ‚‚ (24-50%), not 100%. Nasal cannula (C) reaches 40%. The document's answer (D) fits nonrebreather's reservoir ensures high FiOâ‚‚, critical for ARDS-like pneumonia, distinguishing it from A's lower capacity or C's inadequacy.

Correct Answer: D

Rationale: Normal breathing is controlled by the ventral and dorsal respiratory groups in the medulla and pons. The dorsal group initiates inspiration, stimulating the diaphragm via the phrenic nerve, while the ventral group adjusts forceful breathing, and the pons refines rhythm together maintaining automatic respiration based on CO2 levels. Lungs execute breathing but don't control it they respond to neural signals. This brain stem coordination ensures steady, involuntary breathing, adapting to metabolic needs, a critical autonomic process distinct from voluntary control, foundational in respiratory physiology and clinical monitoring of breathing disorders.

Correct Answer: D

Rationale: The auricle, a pouch-like extension of the atrium, increases its filling capacity, allowing more blood storage during diastole, enhancing atrial volume. The ventricle pumps blood, not a storage pouch. The coronary sulcus is a groove for coronary vessels, not a capacity structure. The fossa ovalis, a fetal remnant, doesn't affect volume. Auricles, wrinkled and ear-like, expand atrial space, aiding preload more prominent on the left crucial for optimizing cardiac output, a subtle but significant feature in heart anatomy and function assessment.

Correct Answer: A

Rationale: The coronary arteries distribute oxygenated blood to the myocardium, branching from the aorta's base to supply cardiac muscle, ensuring its high metabolic demand is met. Coronary veins and the sinus drain deoxygenated blood back to the right atrium, not supply it. The vena cava delivers systemic deoxygenated blood, not to the heart muscle. These arteries left and right encircle the heart, a lifeline for its function, critical in coronary artery disease where blockages starve myocardium, leading to ischemia or infarction.

Correct Answer: D

Rationale: The vagus nerve (cranial nerve X), via parasympathetic fibers, reduces heart rate by releasing acetylcholine, slowing SA node firing and AV conduction, dropping beats from ~100 to ~70 bpm at rest. Cardiac accelerator nerves (sympathetic) increase rate. The hypoglossal nerve controls tongue movement, not heart. The spinal accessory nerve moves neck muscles, irrelevant here. Vagal stimulation, part of the 'rest and digest' response, balances sympathetic drive, a key autonomic regulator, critical in bradycardia and vagal maneuvers to slow tachycardias.