If dietary iodine levels are deficient you would expect that plasma TSH levels would be ________ and that plasma thyroxine levels would be ________.
A) high; low
B) low; high
C) unchanged; low
D) low; unchanged
E) low; low

Question

Quizplus · Accepted Answer

When dietary iodine levels are deficient, the production of thyroid hormones is impaired, resulting in an increase in plasma TSH levels. TSH levels rise as the body attempts to stimulate the thyroid gland to produce more hormones. However, as the thyroid gland cannot produce hormones without iodine, plasma thyroxine levels will be low. Therefore, the correct answer is A, high TSH levels and low thyroxine levels.

If Dietary Iodine Levels Are Deficient You Would Expect That