A patient asks the nurse why an infection in his upper respiratory system is affecting the clarity of his speech. Which structure serves as the patient's resonating chamber in speech?

Correct Answer: C

Rationale: Rationale: The paranasal sinuses act as resonating chambers in speech production due to their location near the nasal cavity and their ability to amplify sound vibrations. When infected, the sinuses can become inflamed, affecting speech clarity. The trachea (A) is a passageway for air, not involved in speech. The pharynx (B) is a common pathway for both air and food, not a resonating chamber. The larynx (D) contains the vocal cords for sound production but is not primarily responsible for speech resonance.

Correct Answer: C

Rationale: To calculate pulmonary ventilation rate, multiply tidal volume by respiration rate. In this case, 500 mL * 14 bpm = 7,000 mL/min. Converting to liters, it's 7 L/min. Choice A is incorrect as it miscalculates the conversion from mL to L, B is incorrect due to incorrect calculation, and D is incorrect as it's not the accurate result of the multiplication.

Correct Answer: A

Rationale: Step 1: Blood flow supplies oxygen and removes carbon dioxide in the lungs, essential for efficient gas exchange. Step 2: Decreased blood flow means less oxygen delivery and carbon dioxide removal, leading to decreased respiratory efficiency. Step 3: Choice A is correct as it directly impacts the gas exchange process. Summary: - Choice B (increased surface area) would enhance gas exchange efficiency. - Choice C (increased partial pressure gradients) would improve gas exchange efficiency. - Choice D (increased gas solubility) would not directly affect respiratory efficiency.

Correct Answer: C

Rationale: The correct answer is C because the Dorsal Respiratory Group (DRG) and Ventral Respiratory Group (VRG) are the centers in the brainstem responsible for controlling the rate and depth of breathing. The DRG primarily regulates inspiration, while the VRG is involved in both inspiration and expiration. The apneustic and pneumotaxic centers (choices A and B) are subregions within the pons that modulate the activity of the DRG and VRG but do not establish the baseline rate and depth of breathing. The expiratory center (choice D) is responsible for controlling only the expiratory phase of breathing and is not involved in setting the normal rate and depth of breathing.

Correct Answer: D

Rationale: The correct answer is D. Inhibition of medulla oblongata chemoreceptors and respiratory muscles would decrease respiratory rate, leading to decreased elimination of CO2 at alveoli. This would cause an increase in arterial PCO2 due to less CO2 being removed from the body. Therefore, choice D is correct. Choices A, B, and C are incorrect because they do not align with the physiological effects of inhibiting the medulla oblongata chemoreceptors and respiratory muscles. Option A suggests an increase in respiratory rate and elimination of CO2, which goes against the expected decrease in these parameters. Option B proposes an increase in respiratory rate but a decrease in CO2 elimination and arterial PCO2, which is inconsistent with the expected outcomes. Option C suggests an increase in respiratory rate and CO2 elimination but a decrease in arterial PCO2, which does not follow the logic of the question.