ATI LPN
NCLEX PN Questions on Respiratory System Questions
Question 1 of 5
Contraction of the atria of the heart leads to blood moving directly
Correct Answer: D
Rationale: Atrial contraction (atrial systole) pushes blood through atrioventricular valves tricuspid to the right ventricle, mitral to the left topping off ventricular filling before systole. Auricles are atrial extensions, not destinations. Arteries receive blood from ventricles, not atria. Veins deliver to atria, not from them. This valve passage, late in diastole, boosts ventricular volume by 20-30%, enhancing stroke volume, a subtle but vital step in the cardiac cycle, critical in understanding preload and atrial contribution to heart efficiency.
Question 2 of 5
Isovolumetric contraction is the phase of the cardiac cardiac cycle in which
Correct Answer: D
Rationale: Isovolumetric contraction, early ventricular systole, sees pressure rise as myocardium contracts, but volume stays constant all valves (AV, semilunar) are closed, no blood enters or exits. Semilunar valves open later (ejection). Repolarization is post-systole. Atrial depolarization precedes this. This brief phase (~50 ms) builds pressure to exceed arterial levels, key in cycle timing, critical in heart sound analysis and dysfunction where pressure fails to rise adequately.
Question 3 of 5
The right atrioventricular valve is also called the:
Correct Answer: B
Rationale: The right atrioventricular (AV) valve is the tricuspid, with three cusps, preventing backflow from right ventricle to atrium. Bicuspid and mitral are left-sided (same valve); aortic is semilunar, not AV. This naming reflects its tri-leaflet design, key in right heart flow, critical in tricuspid issues like regurgitation, a precise valve identity.
Question 4 of 5
The organ of the respiratory system that closes when food is being swallowed is the:
Correct Answer: C
Rationale: The larynx (C) closes during swallowing, per the key the epiglottis seals the glottis, preventing aspiration. The nose (A) stays open (no closure mechanism). The pharynx (B) conducts food/air but doesn't close. The trachea (D) remains patent (cartilage rings). Swallowing's pharyngeal phase (0.5 s) tilts the epiglottis via hyoid movement, per anatomy laryngeal closure protects lungs (e.g., 1-2 L food/day diverted). This distinguishes C from A's irrelevance, B's conduit role, or D's openness the larynx's gatekeeping is unique.
Question 5 of 5
A client is hospitalized with a diagnosis of pneumonia. Which findings, based on the nurse's knowledge, are indicative of deteriorating clinical state? Select all that apply.
Correct Answer: A
Rationale: Increased respiratory rate (A), tachycardia (B), agitation (C), and cyanosis (D) signal pneumonia deterioration, per document (1-4). Tachypnea (e.g., RR >30) reflects hypoxemia (PaOâ‚‚ <60 mmHg). Tachycardia (HR >100) compensates low Oâ‚‚. Agitation indicates cerebral hypoxia. Cyanosis (SpOâ‚‚ <90%) shows deoxygenation. Urine output is unrelated. A's priority RR doubling drives hypoxia detection, distinguishing it from E's irrelevance.