Chapter 16, Problem 9CYR

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. About 90% of the thyroid hormone produced is triiodothyronine $\left({\text{T}}_3\right)$.

b. Thyroxine $\left({\text{T}}_4\right)$ is the more active of the two thyroid hormones.

c. Thyroid hormones are produced by follicle cells.

d. Iodine atoms are a key component of parathyroid hormone.

e. Excess secretion of thyroid hormones produces weight gain, cold intolerance, and slow heart rate.