When the nurse reads the diagnosis of centrilobar emphysema, the nurse recognizes that this type of emphysema is characterized by:

Correct Answer: B

Rationale: The correct answer is B because centrilobar emphysema is characterized by enlarged and broken down bronchioles with intact alveoli. This type of emphysema primarily affects the respiratory bronchioles and alveolar ducts in the upper lung lobes. The other choices are incorrect because: A) Significant smoking history is usually present in patients with centrilobar emphysema. C) Hypoelastic bronchi and bronchioles are not characteristic of centrilobar emphysema. D) Deficiency of the enzyme inhibitor alpha-1 antitrypsin is associated with a different type of emphysema called panlobar emphysema, not centrilobar emphysema.

Correct Answer: D

Rationale: Carbonic anhydrase catalyzes the reversible reaction between carbon dioxide and water to form carbonic acid, which then dissociates into bicarbonate and hydrogen ions. It is indeed found in red blood cells, aiding in CO2 transport. Therefore, all the statements are true, making option D the correct answer.

Correct Answer: D

Rationale: The correct answer is D: expiratory reserve volume. After normal exhalation (tidal volume), the expiratory reserve volume represents the additional volume of air that can be forcefully exhaled. This volume is used during activities requiring increased breathing effort. Choices A and C are incorrect because tidal volume is the volume of air inhaled or exhaled during normal breathing, and inspiratory reserve volume is the extra volume of air that can be inhaled after a normal inhalation. Choice B, residual volume, is the volume of air remaining in the lungs after maximal exhalation and cannot be exhaled voluntarily.

Correct Answer: C

Rationale: The correct answer is C: 500 ml. Tidal volume refers to the amount of air inspired or expired during normal breathing. In adult humans, the average tidal volume is around 500 ml. This volume represents the typical amount of air exchanged with each breath. Choices A, B, and D are incorrect because they do not accurately reflect the standard tidal volume in human beings. Option A (1000 ml) and B (1500 ml) are too high for a normal tidal volume, while option D (4.5 ml) is too low. Therefore, the correct answer is C as it aligns with the average tidal volume in human beings.

Correct Answer: D

Rationale: The correct answer is D: Spasm in bronchial muscles. Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, leading to difficulty breathing. Bronchial muscles in the airways undergo spasms, causing constriction and making it hard to breathe. Infection of the trachea (A) or lungs (B) may lead to respiratory symptoms but is not the primary cause of asthma. Bleeding into the pleural cavity (C) is unrelated to the pathophysiology of asthma. Therefore, the correct answer is D as it directly correlates with the underlying mechanism of asthma.