Of the four parts of respiration the part when oxygen and carbon dioxide are exchanged in the capillaries lining the alveoli in the lungs is:

Correct Answer: B

Rationale: The correct answer is B: external respiration. This is the part of respiration where oxygen and carbon dioxide are exchanged in the capillaries lining the alveoli in the lungs. During external respiration, oxygen from the alveoli diffuses into the bloodstream while carbon dioxide from the bloodstream diffuses into the alveoli to be exhaled. A: Pulmonary ventilation refers to the process of breathing, specifically the movement of air in and out of the lungs. This does not involve the actual exchange of gases in the alveoli. C: Transport of respiratory gases involves the movement of oxygen and carbon dioxide through the bloodstream to and from the tissues. This is not specifically related to the exchange of gases in the alveoli. D: Internal respiration refers to the exchange of gases between the bloodstream and the tissues at the cellular level. This does not specifically occur in the alveoli of the lungs.

Correct Answer: B

Rationale: The correct answer is B: Non-rebreather mask. This device provides the highest concentration of oxygen among the choices, around 80-100%. In a client with difficulty breathing and low oxygen saturation, a high concentration of oxygen is crucial to quickly reverse hypoxemia. The non-rebreather mask ensures that the client is receiving the maximum amount of oxygen with each breath, improving oxygenation rapidly. A: Simple mask delivers a lower concentration of oxygen and would not be sufficient for a client in distress. C: Face tent does not provide a high concentration of oxygen and may not be effective in quickly reversing hypoxemia. D: Nasal cannula delivers a lower concentration of oxygen compared to the non-rebreather mask and may not be enough to reverse manifestations in a client with significant difficulty breathing and low oxygen saturation.

Correct Answer: C

Rationale: The correct answer is C: Relax smooth muscles of the bronchial airway. Aminophylline (theophylline) is a bronchodilator that works by relaxing the smooth muscles in the bronchial airways, which helps to open up the airways and improve airflow. This action helps to relieve bronchospasm, which is common in conditions like acute bronchitis. Promoting expectoration (A) and suppressing cough (B) are not the primary actions of aminophylline, although they may be secondary effects. Preventing infection (D) is unrelated to the mechanism of action of aminophylline in treating acute bronchitis.

Correct Answer: B

Rationale: The correct answer is B: A lobe of the lung. During a lobectomy, a lobe of the lung is surgically removed, typically to treat lung cancer while preserving the remaining lung tissue. Removing one entire lung (choices A and D) is not necessary for a lobectomy and would be a more extensive procedure. Choice C, removing a small localized area near the surface of the lung, does not accurately reflect the extent of tissue removal required for a lobectomy. Therefore, the correct choice is B as it specifically addresses the removal of a lobe during the surgical procedure.

Correct Answer: B

Rationale: During inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity. This decrease in pressure within the thoracic cavity creates a pressure gradient, causing air to flow into the lungs where the pressure is now higher. Choice B is correct because the pressure in the thoracic cavity is indeed less than the pressure within the lungs during inhalation. Choices A, C, and D are incorrect because during inhalation, the pressure in the thoracic cavity decreases, the diaphragm moves downward and flattens, and the chest cavity volume increases to allow for air intake.