23. What are the hormones
secreted by the thyroid gland?
What are their functions?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
The thyroid secretes the
thyroxine (T4), triiodothyronine (T3)
calcitonin.

T3 and T4 iodinated substances
derived from amino acid tyrosine.
They to increase the cellular
rate of the body (
respiration, metabolism of proteins
lipids, etc.). Calcitonin inhibits
release of calcium cations the bones
thus controlling blood level of
calcium.