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Question #46331
The Question
A patient suffering from chronic hypoventilation presents with severe hypercapnia and a marked reduction in systemic arterial pH. Based on the principles of gas exchange and respiratory regulation, which of the following best describes the physiological fallout in this patient?
Options
- A.
The oxygen dissociation curve shifts to the left, and the pneumotaxic center increases the duration of inspiration to expel excess CO2.
- B.
The buffering capacity of deoxyhemoglobin is compromised due to carbaminohemoglobin saturation, and the medullary chemosensitive area becomes blunted to elevated H+ ions.
- C.
The Haldane effect is amplified in systemic capillaries, causing hemoglobin to release O2 more readily in response to the high pCO2.
- D.
Peripheral chemoreceptors in the aortic arch become insensitive to pO2 changes, relying entirely on the medulla to detect the falling pH.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Hemoglobin-CO2 Binding Sites|Oxygen-Hemoglobin Dissociation Curve|Neural Regulation Feedback
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse the Bohr effect (CO2/H+ affecting O2 affinity) with the Haldane effect (O2 affecting CO2 affinity).
Furthermore, a common misconception is that the medullary chemoreceptors will infinitely increase ventilation in response to CO2; in reality, chronic hypercapnia overwhelms Hb buffering and blunts central chemoreceptor sensitivity, shifting the respiratory drive to peripheral hypoxia.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Breathing and Exchange of Gases - Class 11 |
| Concept | Hemoglobin-CO2 Binding Sites |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |