LPN exams respiratory practice questions set 2

Correct answer:

Infant respiratory distress syndrome (IRDS), or hyaline membrane disease, occurs in premature infants due to insufficient surfactant production by immature type II alveolar cells. Surfactant lowers alveolar surface tension (T), facilitating lung expansion. In IRDS, reduced surfactant leads to increased surface tension, causing alveoli to collapse (atelectasis) after each breath. This high tension decreases lung compliance (C), as the lungs become stiffer and harder to inflate, requiring greater pressure for ventilation. Consequently, collapsed alveoli impair gas exchange, reducing arterial oxygen partial pressure (PaO2) below normal (hypoxemia), often to levels like 50-60 mmHg instead of the typical 75-100 mmHg. The correct combination increased T, decreased C, decreased PaO2 reflects the pathophysiology of IRDS, where surfactant deficiency drives a cascade of respiratory challenges. Other combinations, like increased compliance or unchanged PaO2, contradict the condition's mechanics, where stiff lungs and poor oxygenation are hallmark features.

Correct answer:

Diffusion rate, per Fick's law, depends on surface area (choice A), concentration gradient (choice B), solubility (choice C), and membrane thickness (choice E), but not directly on molecular weight of gas (choice D), making D correct. Surface area increases diffusion by providing more space for gas exchange, as seen in alveoli. The concentration gradient (partial pressure difference) drives diffusion, e.g., Oâ‚‚ from alveoli to blood. Solubility affects how easily gases dissolve in the membrane, with COâ‚‚ diffusing faster than Oâ‚‚ due to higher solubility. Thickness inversely affects rate; thinner alveolar walls enhance diffusion. Molecular weight influences diffusion speed in free gas (Graham's law), but in the lung's aqueous environment, solubility dominates over molecular weight for Oâ‚‚ and COâ‚‚ exchange across membranes. Studies show diffusion capacity correlates with solubility and pressure gradients, not molecular weight, in physiological contexts, confirming D as the factor least affecting diffusion rate here.

Correct answer:

Infant respiratory distress syndrome (IRDS), or hyaline membrane disease, occurs in premature infants due to insufficient surfactant production by immature type II alveolar cells. Surfactant lowers alveolar surface tension (T), facilitating lung expansion. In IRDS, reduced surfactant leads to increased surface tension, causing alveoli to collapse (atelectasis) after each breath. This high tension decreases lung compliance (C), as the lungs become stiffer and harder to inflate, requiring greater pressure for ventilation. Consequently, collapsed alveoli impair gas exchange, reducing arterial oxygen partial pressure (PaO2) below normal (hypoxemia), often to levels like 50-60 mmHg instead of the typical 75-100 mmHg. The correct combination increased T, decreased C, decreased PaO2 reflects the pathophysiology of IRDS, where surfactant deficiency drives a cascade of respiratory challenges. Other combinations, like increased compliance or unchanged PaO2, contradict the condition's mechanics, where stiff lungs and poor oxygenation are hallmark features.

Correct answer:

Fick's law of diffusion states that the rate of gas diffusion across a membrane (e.g., alveolar-capillary) is proportional to the surface area (A), diffusion coefficient (D), and partial pressure gradient (ΔP), and inversely proportional to diffusion distance (d): Rate = (A × D × ΔP) / d. When comparing different gases (e.g., O2 vs. CO2), the diffusion coefficient (D) varies most significantly, as it depends on gas solubility and molecular weight (D ∝ solubility / √MW). CO2's solubility is ~20 times higher than O2's (0.51 vs. 0.024 ml/mmHg/L), though O2's molecular weight is slightly lower (32 vs. 44), making CO2 diffuse ~20 times faster despite similar gradients. Partial pressure gradient drives diffusion but is gas-specific and often comparable (e.g., O2: 100-40 mmHg, CO2: 46-40 mmHg). Temperature and distance affect all gases similarly in the lung. Thus, the diffusion coefficient has the most pronounced effect across different gases, explaining why CO2 equilibrates faster than O2 across the respiratory membrane.

Correct answer:

The correct answer is C: Maintain a nonjudgmental attitude to avoid causing the client to feel guilty. This is important because the nurse needs to establish trust with the client to obtain accurate information about their health history. Being nonjudgmental creates a safe space for the client to share openly, which is crucial for effective assessment and planning of care. Choice A is incorrect because while it is important for the client to quit smoking, addressing this issue at the first encounter may not be the most effective approach and could potentially alienate the client. Choice B is also incorrect as the focus should be on building rapport and obtaining accurate information relevant to the client's current health status. Encouraging honesty about substance use is important but not the most critical action in this context. Choice D is incorrect as the nurse should provide information and support to the client based on the client's needs and wishes, rather than making assumptions about their preferences or prognosis.

Correct answer:

Pulmonary vascular resistance (PVR) reflects opposition to blood flow in the pulmonary circulation, influenced by lung volume and vessel mechanics. At high lung volumes (near TLC), extra-alveolar vessels stretch and narrow, and alveolar capillaries compress, increasing PVR. At low volumes (near RV), these vessels are less stretched and more patent, lowering PVR, though this isn't the queried truth. The true statement is that increased PVR can lead to right heart failure, as seen in conditions like pulmonary hypertension or fibrosis, where elevated resistance overworks the right ventricle, causing cor pulmonale. PVR isn't measured by routine pulmonary function tests (e.g., spirometry), which assess airflow and volumes, not vascular pressures cardiac catheterization is required instead. The link to right heart failure is critical, as chronic high PVR elevates pulmonary artery pressure, straining the heart's ability to pump against it, a key pathophysiological consequence distinguishing this option as true amid the others' inaccuracies.

Correct answer:

Pulmonary vascular resistance (PVR) reflects opposition to blood flow in the pulmonary circulation, influenced by lung volume and vessel mechanics. At high lung volumes (near TLC), extra-alveolar vessels stretch and narrow, and alveolar capillaries compress, increasing PVR. At low volumes (near RV), these vessels are less stretched and more patent, lowering PVR, though this isn't the queried truth. The true statement is that increased PVR can lead to right heart failure, as seen in conditions like pulmonary hypertension or fibrosis, where elevated resistance overworks the right ventricle, causing cor pulmonale. PVR isn't measured by routine pulmonary function tests (e.g., spirometry), which assess airflow and volumes, not vascular pressures cardiac catheterization is required instead. The link to right heart failure is critical, as chronic high PVR elevates pulmonary artery pressure, straining the heart's ability to pump against it, a key pathophysiological consequence distinguishing this option as true amid the others' inaccuracies.

Correct answer:

The correct answer is A. A client with suspected tuberculosis is likely to experience fatigue, weight loss, low-grade fevers, and night sweats due to the chronic infection affecting the body. Fatigue and weight loss are common symptoms of active tuberculosis due to the systemic impact of the infection. Low-grade fevers and night sweats are characteristic of tuberculosis due to the body's immune response. These symptoms are key indicators of tuberculosis infection. Choices B, C, and D are incorrect because they describe symptoms that are not typically associated with tuberculosis. Dyspnea, chest pain, and cough (Choice B) are more commonly seen in respiratory conditions such as pneumonia or bronchitis. Rapid shallow breathing, prolonged labored expiration, and stridor (Choice C) are indicative of airway obstruction rather than tuberculosis. Dyspnea, hypoxemia, and decreased pulmonary compliance (Choice D) are more characteristic of conditions such as chronic obstructive pulmonary disease (COPD) rather than tuberculosis.

Correct answer:

Fick's law of diffusion states that the rate of gas diffusion across a membrane (e.g., alveolar-capillary) is proportional to the surface area (A), diffusion coefficient (D), and partial pressure gradient (ΔP), and inversely proportional to diffusion distance (d): Rate = (A × D × ΔP) / d. When comparing different gases (e.g., O2 vs. CO2), the diffusion coefficient (D) varies most significantly, as it depends on gas solubility and molecular weight (D ∝ solubility / √MW). CO2's solubility is ~20 times higher than O2's (0.51 vs. 0.024 ml/mmHg/L), though O2's molecular weight is slightly lower (32 vs. 44), making CO2 diffuse ~20 times faster despite similar gradients. Partial pressure gradient drives diffusion but is gas-specific and often comparable (e.g., O2: 100-40 mmHg, CO2: 46-40 mmHg). Temperature and distance affect all gases similarly in the lung. Thus, the diffusion coefficient has the most pronounced effect across different gases, explaining why CO2 equilibrates faster than O2 across the respiratory membrane.

Correct answer:

Diffusion rate, per Fick's law, depends on surface area (choice A), concentration gradient (choice B), solubility (choice C), and membrane thickness (choice E), but not directly on molecular weight of gas (choice D), making D correct. Surface area increases diffusion by providing more space for gas exchange, as seen in alveoli. The concentration gradient (partial pressure difference) drives diffusion, e.g., Oâ‚‚ from alveoli to blood. Solubility affects how easily gases dissolve in the membrane, with COâ‚‚ diffusing faster than Oâ‚‚ due to higher solubility. Thickness inversely affects rate; thinner alveolar walls enhance diffusion. Molecular weight influences diffusion speed in free gas (Graham's law), but in the lung's aqueous environment, solubility dominates over molecular weight for Oâ‚‚ and COâ‚‚ exchange across membranes. Studies show diffusion capacity correlates with solubility and pressure gradients, not molecular weight, in physiological contexts, confirming D as the factor least affecting diffusion rate here.