Nurse Oliver observes constant bubbling in the water-seal chamber of a closed chest drainage system. What should the nurse conclude?

Correct Answer: C

Rationale: The nurse should conclude that the closed chest drainage system has an air leak. Constant bubbling in the water-seal chamber indicates air is escaping from the system, which can lead to a loss of negative pressure needed for proper chest drainage. This could result in inadequate lung re-expansion and increased risk of pneumothorax. A: Incorrect, constant bubbling is not normal. B: Incorrect, pneumothorax would not cause constant bubbling. D: Incorrect, chest tube obstruction would not cause bubbling in the water-seal chamber.

Correct Answer: D

Rationale: The correct answer is D: Frequent, small meals. This is recommended for a dyspneic patient to prevent feeling overly full and to reduce the effort required for digestion, thus minimizing the risk of exacerbating breathing difficulties. Three large meals (A) would likely cause discomfort and increase difficulty in breathing. A low-protein emphasis (B) is not specifically indicated for dyspneic patients unless there are underlying conditions that require protein restriction. A low-calorie emphasis (C) may lead to inadequate nutrient intake, which is crucial for supporting the body's overall health and healing process.

Correct Answer: D

Rationale: The correct answer is D because ventilation in humans is powered by the diaphragm and muscles attached to the ribs working together. The diaphragm contracts during inhalation, increasing the volume of the thoracic cavity, while the external intercostal muscles lift the rib cage, expanding the chest cavity. This creates a pressure difference, causing air to move into the lungs. The other choices are incorrect because the lungs themselves do not have the ability to power ventilation independently, and muscles attached to the ribs are essential for chest expansion during breathing.

Correct Answer: C

Rationale: Step-by-step rationale for why choice C is correct: 1. During inhalation, the diaphragm contracts and moves downward, expanding the thoracic cavity. 2. Expansion of the thoracic cavity leads to a decrease in alveolar pressure and intrapleural pressure. 3. Decreased alveolar pressure causes air to flow into the lungs due to the pressure difference. 4. Decreased intrapleural pressure helps keep the lungs inflated by maintaining the pleural cavity pressure lower than alveolar pressure. Summary of why other choices are incorrect: A. Incorrect because alveolar pressure decreases during inhalation, but intrapleural pressure also decreases. B. Incorrect because both alveolar pressure and intrapleural pressure decrease during inhalation. D. Incorrect because alveolar pressure decreases and intrapleural pressure also decreases during inhalation, not increases.

Correct Answer: D

Rationale: The correct answer is D: Diaphragm. The diaphragm is a dome-shaped muscle that separates the thoracic and abdominal cavities in mammals. It contracts during inhalation, expanding the thoracic cavity and allowing the lungs to fill with air. This physiological function clearly demonstrates that the diaphragm is the structure responsible for partitioning the body cavity. A: Liver - The liver is located in the abdominal cavity and does not partition the thoracic and abdominal cavities. B: Lungs - Lungs are organs within the thoracic cavity but do not partition the two cavities. C: Ribs - Ribs protect the thoracic organs but do not partition the body cavity into thoracic and abdominal regions.