Question

Iodine 131 is administered orally to test the function of:

• A. Liver
• B. Spleen
• C. Gastro intestinal tract
• D. Thyroid

Hint:

Iodine = Thyroid. They go together like a lock and key.

Answer 1

The Correct Option is D

Step 1: Concept
Iodine is a key element required by the human body specifically for the synthesis of thyroid hormones (T3 and T4).

Step 2: Meaning
The thyroid gland actively "traps" or concentrates iodine from the bloodstream.

Step 3: Analysis
By using the radioactive isotope Iodine-131 ($I^{131}$), physicians can monitor the rate and quantity of iodine uptake by the thyroid gland to diagnose hyperthyroidism or hypothyroidism.

Step 4: Conclusion
Iodine-131 is the gold standard tracer for evaluating thyroid function.

Final Answer: (D)