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Question #45423
The Question
A patient presents with symptoms of lethargy and weight gain. Hormonal analysis reveals significantly reduced levels of and , but highly elevated levels of Thyroid Stimulating Hormone (TSH). Serology confirms an autoimmune disorder where autoantibodies target the enzyme responsible for the oxidation of iodide in the thyroid follicles. Which of the following statements is INCORRECT regarding this patient's physiological state?
Options
- A.
The autoantibodies primarily inhibit thyroid peroxidase, disrupting the organification of iodine and coupling of iodotyrosines.
- B.
The elevated TSH is a direct result of the loss of negative feedback inhibition on the pars distalis and hypothalamus.
- C.
Administration of exogenous TSH will successfully restore normal thyroxine levels by hyper-stimulating the surviving follicular cells.
- D.
This condition exemplifies a breakdown of self-tolerance, leading to the destruction of the thyroid gland.
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
Thyroperoxidase|Thyroglobulin|Autoimmunity Principles
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between Primary and Secondary Endocrine Failure.
Students often assume that applying a stimulating hormone (TSH) will force the target gland to produce its hormone.
However, in primary autoimmune failure, the target tissue's synthetic machinery (TPO enzyme) is blocked or destroyed, rendering it completely unresponsive to trophic hormones.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | Thyroid Hormone Synthesis |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |