Mammalian RBC respire anaerobically because

Correct Answer: C

Rationale: The correct answer is C because mammalian RBCs lack mitochondria, which are responsible for aerobic respiration. Without mitochondria, RBCs are unable to perform oxidative phosphorylation to generate ATP aerobically. Stroma (A) is found in chloroplasts, not RBCs. Hemoglobin (B) is responsible for oxygen transport, not cellular respiration. Bicarbonate ions (D) are involved in the buffering system of blood, not in cellular respiration. Therefore, the lack of mitochondria is the key reason for RBCs to respire anaerobically.

Correct Answer: D

Rationale: The correct answer is D because Chronic Obstructive Pulmonary Disease (COPD) is an umbrella term that encompasses both emphysema and bronchitis. Emphysema is characterized by damage to the air sacs in the lungs, while bronchitis involves inflammation of the bronchial tubes. Asthma, on the other hand, is a separate condition characterized by reversible airway obstruction. Therefore, choices A, B, and C are incorrect, as only emphysema and bronchitis fall under the category of COPD.

Correct Answer: C

Rationale: The correct answer is C. Lung fields dull to percussion, absent breath sounds, and a pleural friction rub are consistent with pleural effusion. Dullness on percussion indicates fluid accumulation in the pleural space. Absent breath sounds suggest decreased air movement due to the fluid. A pleural friction rub may be heard due to inflammation of the pleura. A is incorrect because increased tactile fremitus, egophony, and a dull sound upon percussion are more indicative of pneumonia. B is incorrect because decreased tactile fremitus, wheezing, and a hyperresonant sound upon percussion are more indicative of COPD or emphysema. D is incorrect because normal tactile fremitus, decreased breath sounds, and a resonant sound upon percussion are more indicative of asthma or atelectasis.

Correct Answer: D

Rationale: The correct answer is D because withholding food and fluids for several hours before a bronchoscopy is important to prevent aspiration during the procedure. When the patient is sedated for the bronchoscopy, there is an increased risk of vomiting, and having an empty stomach reduces this risk. Administering IV fluids (choice A) is not necessary unless clinically indicated. Inserting a peripherally inserted central catheter (choice B) is not typically required for a bronchoscopy. Administering nebulized bronchodilators (choice C) may not be needed for all patients and should be based on the individual's respiratory condition.

Correct Answer: B

Rationale: The correct answer is B: an increase of the respiratory rate. When carbon dioxide levels rise in the blood, it triggers the body to increase the rate of breathing to eliminate excess carbon dioxide through exhalation. This is known as the respiratory drive, controlled by the respiratory centers in the brainstem. Increasing the respiratory rate helps to restore the balance of gases in the blood. Incorrect Choices: A: Decrease in the rate of breathing - This is incorrect because high levels of carbon dioxide would stimulate an increase in breathing rate, not a decrease. C: Decrease of pulmonary ventilation - This is incorrect as an increase in carbon dioxide would typically lead to an increase, not a decrease, in pulmonary ventilation. D: Decrease of the alveolar ventilation rate - This is incorrect because an increase in carbon dioxide would prompt an increase in alveolar ventilation to remove excess carbon dioxide from the blood.