A patient has a diagnosis of multiple sclerosis. The nurse is aware that neuromuscular disorders such as multiple sclerosis may lead to a decreased vital capacity. What does vital capacity measure?

Correct Answer: D

Rationale: The correct answer is D because vital capacity measures the maximal volume of air exhaled from the point of maximal inspiration. This measurement includes the tidal volume, inspiratory reserve volume, and expiratory reserve volume. A is incorrect because it describes tidal volume. B is incorrect because it describes total lung capacity. C is incorrect because it describes inspiratory capacity. Therefore, D is the most appropriate choice for measuring vital capacity accurately in a patient with neuromuscular disorders like multiple sclerosis.

Correct Answer: D

Rationale: The correct answer is D: intrapleural pressure. Intrapleural pressure refers to the pressure within the pleural cavity, which is the space between the lungs and chest wall. This pressure is lower than atmospheric pressure, allowing the lungs to remain inflated. In space labeled '4', the pressure should be intrapleural pressure since it represents the pleural cavity. A: Alveolar pressure is the pressure within the alveoli of the lungs, not in the pleural cavity. B: Interpleural pressure is not a term commonly used in respiratory physiology. C: Subalveolar pressure is not a recognized term in respiratory physiology.

Correct Answer: B

Rationale: The correct answer is B: 20. The average human body consumes about 250 ml of oxygen per minute, and the lungs extract roughly one-fourth of this amount. Since the total cardiac output is around 5 liters per minute, and each liter of blood carries approximately 20 ml of oxygen, each 100 ml of blood leaving the alveolar capillaries would carry away roughly 20 ml of oxygen. Choice A (10 ml) is too low, as it does not account for the efficient oxygen extraction by the lungs. Choice C (30 ml) is too high, exceeding the typical oxygen-carrying capacity of blood. Choice D (50 ml) is also too high, as it overestimates the amount of oxygen carried by each 100 ml of blood.

Correct Answer: A

Rationale: If the dorsal respiratory group of neurons in the medulla oblongata were destroyed bilaterally, a person would stop breathing. This group is responsible for initiating inspiration by sending signals to the diaphragm and intercostal muscles. Without this neural input, the respiratory centers in the brainstem would not receive the necessary signals to stimulate breathing. Pulmonary ventilation would not increase markedly or the respiratory minute volume increase because the primary issue is the lack of neural drive for breathing, not an overstimulation of the respiratory system. Tidal volumes would not decrease as a direct consequence of destroying the dorsal respiratory group; it would lead to cessation of breathing altogether.

Correct Answer: A

Rationale: The correct answer is A: bronchopulmonary segment. This segment of the lung is supplied by its own tertiary bronchus, allowing for independent ventilation. Bronchopulmonary segments are functional units of the lung with their own blood supply and bronchial branches. B: Pulmonary lobule is incorrect as it refers to a small unit of lung tissue surrounded by connective tissue septa. C: Interpulmonary segment is not a recognized term in anatomy. D: Respiratory segment is not a specific anatomical term related to the lung's bronchial divisions.