A 56-year-old man comes to the office due to chronic cough and fatigue. The patient has smoked 2 packs of cigarettes daily since age 18. Physical examination shows cyanosis and expiratory wheezes scattered throughout the lungs. During evaluation for long-term oxygen therapy, his respiratory rate decreases shortly after he begins nasal cannular oxygen supplementation. This patient's reduced respiratory rate is most likely caused by a sudden decrease in stimulation of which of the following sensory receptors?

Question

A 56-year-old man comes to the office due to chronic cough and fatigue.  The patient has smoked 2 packs of cigarettes daily since age 18.  Physical examination shows cyanosis and expiratory wheezes scattered throughout the lungs.  During evaluation for long-term oxygen therapy, his respiratory rate decreases shortly after he begins nasal cannular oxygen supplementation.  This patient's reduced respiratory rate is most likely caused by a sudden decrease in stimulation of which of the following sensory receptors?

Quizplus · Accepted Answer

Eductional Objective: Arterial partial pressure of carbon dioxide (PaCO₂) is the major stimulator of respiration in healthy individuals; even a slight increase in PaCO₂ stimulates central chemoreceptors and triggers increased ventilation. In patients with chronic obstructive pulmonary disease, the response to PaCO₂ is blunted and hypoxemia can contribute to respiratory drive. Peripheral chemoreceptors are primarily responsible for sensing arterial partial pressure of oxygen (PaO₂) and can be suppressed with oxygen administration.

A 56-Year-Old Man Comes to the Office Due to Chronic