Triiodothyronine (T3)

question 27

Multiple Choice

Triiodothyronine (T3)

• A) is less potent in vivo than T4.
• B) is the predominant thyroid hormone produced by thyroid gland.
• C) is converted in peripheral tissues directly to reverse T3 (3,3'5' triiodothyronine).
• D) decreases basal metabolic rates of most tissues.
• E) binds to a nuclear receptor.

---

Definitions:

Sexual Maturity

The stage in an organism's life cycle when it becomes capable of reproductive activity.

Secular Trend

Trend that can be seen only by observing several generations, such as the trend toward earlier attainment of adult height and sexual maturity, which began a century ago in some countries.

Primary Sex Characteristics

Organs directly related to reproduction, which enlarge and mature during adolescence.

Gonads

The primary reproductive organs that produce gametes (sperm in males, ova in females) and various sex hormones; the testes in males and ovaries in females.