As anybody who's gone through adolescence knows, hormones can have a huge effect on our bodies and their development. Hormones are also what make us able to flee in the face of danger, rather than freeze in panic. They are also what help us metabolize food. They are produced by such glands as the adrenal and the thyroid and are largely directed by signals from the hypothalamus, a neural control center at the base of the brain. Hormones are released into the bloodstream and stimulate various physiologic activities. Epinephrine, released during fear or excitement, is a hormone. So is cortisol. So is insulin. Of course, the most well-known hormones are the sex hormones -- testosterone for men, and estrogen and progesterone for women.
More Answers from Michael Roizen, MD