The patient has just had an MRI ordered because a routine chest x-ray showed suspicious areas in the right lung. The physician suspects bronchogenic carcinoma. An MRI would most likely be ordered to assess for what in this patient?

Correct Answer: D

Rationale: The correct answer is D: Chest wall invasion. An MRI would be ordered to assess for any potential invasion of the chest wall by the suspected bronchogenic carcinoma. MRI provides detailed imaging of soft tissues and can help determine the extent of tumor invasion beyond the lungs. Explanation: A: Alveolar dysfunction - Alveolar dysfunction is typically assessed using pulmonary function tests or imaging techniques like CT scans, not MRI. B: Forced vital capacity - Forced vital capacity is a measure of lung function and is not typically assessed using MRI. C: Tidal volume - Tidal volume is a measure of the volume of air moved in and out of the lungs during normal breathing and is not assessed using MRI in this context.

Correct Answer: C

Rationale: The correct answer is C: emphysema. Emphysema is a condition characterized by the destruction of alveolar walls, leading to a decrease in alveolar surface area for gas exchange. This reduction in surface area impairs the exchange of oxygen and carbon dioxide in the lungs. In contrast, lung cancer (A) primarily affects lung tissue but may not directly reduce alveolar surface area. Atelectasis (B) refers to the collapse of lung tissue, which can impact ventilation but not necessarily alveolar surface area. Pneumothorax (D) is the presence of air in the pleural space and does not directly affect alveolar surface area.

Correct Answer: A

Rationale: The correct answer is A: olfactory epithelium. The olfactory epithelium is responsible for detecting smells, not providing chemoreceptor input to the respiratory centers in the medulla oblongata. Medullary chemoreceptors, aortic body, and carotid body are all involved in sensing oxygen, carbon dioxide, and pH levels in the blood, providing crucial input to regulate breathing. The olfactory epithelium is not directly involved in respiratory regulation, making it the exception in this context.

Correct Answer: A

Rationale: The inspiratory capacity is the maximum volume of air that can be inhaled after a normal exhalation. It is the sum of tidal volume and inspiratory reserve volume. Tidal volume is the volume of air inhaled and exhaled during normal breathing, while inspiratory reserve volume is the additional air that can be inhaled after a normal inhalation. Therefore, the correct answer is A. Summary of why other choices are incorrect: B: Vital capacity is the maximum volume of air that can be exhaled after a maximum inhalation. It does not include tidal volume, so this choice is incorrect. C: Vital capacity includes inspiratory reserve volume, not tidal volume, so this choice is incorrect. D: Residual volume is the volume of air remaining in the lungs after maximal exhalation, not part of inspiratory capacity. Tidal volume is the only correct component in this choice.

Correct Answer: C

Rationale: The correct answer is C: Total lung capacity. This term refers to the maximum volume of air the lungs can hold after a full forced inhalation. It is the sum of vital capacity and residual volume. Vital capacity (A) is the maximum volume of air that can be exhaled after a maximum inhalation, not the maximum volume of air contained in the lungs. Tidal volume (B) is the volume of air inhaled or exhaled during normal breathing, not the maximum volume. Inspiratory capacity (D) is the maximum volume of air that can be inhaled after a normal exhalation, not the maximum volume of air contained in the lungs.