Before You Begin

Question #46373

Difficulty: 8/10 | 🟢 Free

The Question

In a clinical case of severe left ventricular failure, a patient develops pulmonary edema. How does this condition specifically impact the physics of gas exchange and the oxygen-hemoglobin dissociation curve?

Options

A.
The increased thickness of the diffusion membrane impairs $O_2$ loading, which restricts the Haldane effect at the alveoli, leading to hypercapnia and a pronounced rightward shift of the dissociation curve at the systemic tissues.
B.
Fluid accumulation in the alveoli directly inhibits the Bohr effect in the pulmonary capillaries, causing retention of $CO_2$ and a leftward shift of the dissociation curve at the systemic tissues.
C.
The resulting hypoxemia induces hyperventilation, which completely compensates for the edema by enhancing the Haldane effect at the tissues, leading to respiratory alkalosis.
D.
Systemic hypertension forces blood into the pulmonary circuit, decreasing pulmonary capillary hydrostatic pressure and shifting the oxygen dissociation curve to the left to favor $O_2$ dissociation.

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

Oxyhemoglobin_Dissociation_Curve|Cardiac_Output|Carbonic_Anhydrase

Why This Question Is Tricky

Common Mistakes

Conceptual Pivot: Students often memorize 'Bohr effect = tissues' and 'Haldane effect = lungs' in isolation.

This question tests the integrated understanding that the Haldane effect ( $CO_2$ release) is mechanically driven by $O_2$ binding.

If a physical barrier (edema) prevents $O_2$ loading, the Haldane effect fails, initiating a cascade of hypercapnia and a subsequent Bohr shift (rightward) at the systemic level.

Quick Facts About This Question

Question Information

Subject	Biology
Chapter	Body Fluids and Circulation - Class 11
Concept	Double Circulation Physics
Difficulty	8
Cognitive Load	5
Target Solve Time	120 sec
Access	Free