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.
Lower estrogen levels after menopause may lead to changes in your genital tissues and sexual responsiveness. A decrease in estrogen leads to decreased blood flow to the pelvic region, which can result in needing more time to build arousal and reach orgasm, as well as less genital sensation.