ATI LPN
NCLEX PN Questions on Respiratory System Questions
Question 1 of 5
Which of the following is the function of the trachea?
Correct Answer: B
Rationale: The trachea filters air we breathe, lined with cilia and mucus that trap dust and microbes, preventing lung entry part of the mucociliary escalator. Gaseous exchange occurs in alveoli, not the trachea, which only conducts air. Exhalation is a lung-diaphragm action; the trachea is a passive conduit. 'All' is wrong filtering is its sole listed role. This protective function, supported by C-shaped cartilage keeping it open, ensures clean air reaches the lungs, critical for respiratory health, distinct from exchange or expulsion processes, a key anatomical distinction in airway mechanics.
Question 2 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 3 of 5
During which of the following periods does the largest volume of blood enter the arteries?
Correct Answer: D
Rationale: Ventricular systole is when the largest blood volume enters the arteries left ventricle into the aorta, right into the pulmonary trunk as contraction ejects stroke volume (~70 mL/beat). Atrial diastole fills atria, not arteries. Ventricular diastole fills ventricles, not direct artery entry. Atrial systole adds to ventricular filling (~20-30% of volume), not artery flow. Systole's forceful push, timed with semilunar valve opening, maximizes arterial delivery, key to systemic and pulmonary circulation, a pivotal phase in cardiac output and pressure wave generation.
Question 4 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 5 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.