What are the roles of hormones and homestasis?

Answer:

• Hormones are chemical messengers which are secreted by glands in order to bring about (usually) relatively gradual changes in the body. For example, oestrogen is the female "sex hormone" released by the ovaries from puberty onwards, to encourage the uterus to prepare its lining in anticipation of a fertilised egg; insulin is released by the pancreas to encourage the liver to absorb glucose from the blood (and then convert it to glycogen).
• Homeostasis is specifically "the maintaining of an internal bodily environment." This is achieved by the various systems in the body working together in unison to ensure that temperature/carbon dioxide/water/ion/glucose levels are kept constant.