A medical nurse has admitted a patient to the unit with a diagnosis of failure to thrive. The patient has developed a fever and cough, so a sputum specimen has been obtained. The nurse notes that the sputum is greenish and that there is a large quantity of it. The nurse notifies the patient's physician because these symptoms are suggestive of what?

Correct Answer: C

Rationale: The correct answer is C: Infection. The greenish color and large quantity of sputum suggest an infection in the lungs, typically caused by bacteria. Greenish sputum is often a sign of bacterial pneumonia. Fever and cough are common symptoms of a lung infection, along with increased sputum production. Pneumothorax (A) is characterized by a collapsed lung and does not typically present with greenish sputum. Lung tumors (B) may cause cough and sputum production, but the color of the sputum is not specific to tumors. Pulmonary edema (D) is a condition where fluid accumulates in the lungs, leading to shortness of breath and pink, frothy sputum, not greenish sputum.

Correct Answer: C

Rationale: The correct answer is C: external intercostals. These muscles are responsible for elevating the ribcage during inhalation, which corresponds to the movement labeled '1'. The rectus abdominis (A) is involved in trunk flexion, internal intercostals (B) aid in forced exhalation, and the diaphragm (D) primarily assists in inhalation by moving downward to increase thoracic cavity volume. Therefore, the external intercostals are the correct choice for the specific movement indicated in the question.

Correct Answer: C

Rationale: The correct answer is C: bicarbonate ions. Carbon dioxide in the blood mainly combines with water to form carbonic acid, which dissociates into bicarbonate ions and hydrogen ions. The majority of carbon dioxide is transported in the blood as bicarbonate ions. This process occurs in red blood cells via the enzyme carbonic anhydrase. Choices A and D are incorrect as carbon dioxide mainly combines with water and does not remain as a solute in plasma or cytoplasm. Choice B, carbaminohemoglobin, is a minor way carbon dioxide is transported, where a small amount binds to hemoglobin, but the majority is transported as bicarbonate ions.

Correct Answer: C

Rationale: Damage to the phrenic nerves would result in the inability to fully expand the diaphragm, leading to reliance on costal breathing. This is because the phrenic nerves innervate the diaphragm, the main muscle of respiration. Without proper diaphragmatic function, the individual would have difficulty engaging in effective diaphragmatic breathing. Therefore, choice C is correct. Choices A, B, and D are incorrect because damage to the phrenic nerves would not directly impact the respiratory rate, tidal volume, or pressure differences between the lungs and the outside air. These functions are more related to overall respiratory control and lung mechanics, which are not solely dependent on the phrenic nerves.

Correct Answer: C

Rationale: The correct answer is C: to remove pathogens and debris. Alveolar macrophages are specialized immune cells located in the lungs responsible for engulfing and clearing pathogens, debris, and foreign particles. This function helps maintain lung health and prevents infections. Rationale: 1. Alveolar macrophages are part of the immune system and act as the first line of defense in the lungs. 2. Their primary role is phagocytosis, engulfing and destroying pathogens and debris to protect the respiratory system. 3. Secreting pulmonary surfactant (choice A) is the function of type II alveolar cells, not alveolar macrophages. 4. While alveolar macrophages can secrete some antimicrobial proteins (choice B), their main function is phagocytosis. 5. Facilitating gas exchange (choice D) is the role of the alveoli and not specifically of alveolar macrophages. In summary,