Many steels add to the iron-steel mix other metals that give the entire substance desirable properties such as strength, heat resistance, or flexibility. Steel is considered a mixture rather than a compound because the iron does not chemically bond with the carbon and other components.
Some of estrogen's effects include: 1  Increasing serotonin, and the number of serotonin receptors in the brain. 2  Modifying the production and the effects of endorphins, the feel-good chemicals in the brain. 3  Protecting nerves from damage, and possibly stimulating nerve growth.
Hormones have the following effects on the body: 1  stimulation or inhibition of growth. 2  wake-sleep cycle and other circadian rhythms. 3  mood swings.  induction or suppression of apoptosis (programmed cell 1  death) activation or inhibition of the immune system.  regulation of metabolism.