ATI LPN
Introduction of Respiratory System NCLEX Questions PN Questions
Question 1 of 5
Which valve below prevents blood from flowing back into the right ventricle?
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.
Question 2 of 5
Which of the following chambers of the heart is surrounded by the thickest layer of myocardium?
Correct Answer: D
Rationale: The left ventricle has the thickest myocardium, up to 1-1.5 cm, pumping against high systemic pressure (~120 mmHg) to the aorta, requiring robust muscle. The right ventricle (~0.3-0.5 cm) handles lower pulmonary pressure (~25 mmHg). Atria, thin-walled (~0.1-0.2 cm), only fill ventricles. This thickness gradient reflects workload left ventricle's force sustains body-wide circulation, key in hypertrophy or failure where it thickens or weakens, a core structural adaptation.
Question 3 of 5
Which of the following is not an atrioventricular valve?
Correct Answer: A
Rationale: The aortic valve, a semilunar valve, isn't atrioventricular (AV) it guards the aorta from the left ventricle, not atrium-to-ventricle. Mitral (bicuspid) and tricuspid are AV valves, linking atria to ventricles. This distinction semilunar versus cuspid defines flow roles, key in valve disease like aortic stenosis, a clear anatomical category.
Question 4 of 5
The organ of the respiratory system that is kept open by rings of cartilage is the:
Correct Answer: D
Rationale: The trachea (D) is kept open by C-shaped cartilage rings (16-20), per the key, ensuring airflow (e.g., 6 L/min). The nose (A) has cartilage but not rings for patency. The pharynx (B) lacks cartilage, collapsing without muscle tone. The larynx (C) has cartilage (e.g., thyroid) but not rings. Tracheal rings (1 cm wide) resist collapse under negative pressure (-20 mmHg inspiration), per physiology unlike A's flexible structure, B's muscular tube, or C's vocal framework, D's rigidity maintains the airway.
Question 5 of 5
For the hospitalized client, which manifestation would the nurse assess to be a symptom of pulmonary embolism?
Correct Answer: C
Rationale: Abrupt dyspnea and apprehension (C) are PE symptoms, per document (3). Sudden clot occlusion (e.g., 50% pulmonary artery) drops ventilation (V/Q mismatch), spiking dyspnea (RR >30) and anxiety (fight-or-flight). Slow HR/RR (A) is gradual, not PE. Upper cyanosis (B) is rare central more likely. Wheezing (D) fits asthma. C's acuity onset <5 min flags PE's lethality (10% mortality), unlike A's chronicity.