Multiple choice

Iodine used in thyroid gland is obtained from _____.

  1. lymph

  2. kidney

  3. blood

  4. liver

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The thyroid gland obtains iodine from the bloodstream, not from lymph, kidney, or liver. Iodine absorbed from diet enters blood circulation, which is then taken up by thyroid follicular cells for hormone synthesis.