Almost all our human ups and downs are hormonal. Hormones are powerful chemicals that tell us to grow up, to turn our food into fuel, to continue the human race. They prepare us to fight for our lives or our children's. A hormone is formed within one gland in the body and then carried in the bloodstream to other organs and tissues, where it influences their functions and activities. For instance, estrogen is made in the ovaries.
Nobody knows how many hormones the body makes.
The adrenal gland alone spits out more than 25. After puberty the ovaries begin producing increased levels of sex hormones that prepare the uterus, ovaries and fallopian tubes for ovulation, fertilization or menstruation. Probably the best known of these sex hormones, estrogen, does double duty, affecting sex and fertility as well as the way our bodies process food. It also helps prevent the bone loss of osteoporosis. The calcium balance is necessary for chemical reactions and muscular contractions needed for voluntary movement and even heartbeat.