Just like the nervous system, the endocrine functions are also a body communication system. However, instead of nerves, the endocrine system uses hormones and has a much slower response. It is the second of the body's communication system and has glands that secrete chemical messengers. Hormones form in one tissue and travel through the blood stream which affects other tissues. These hormones influence our body's growth, feelings and triggers drives for things like sex, food, and aggression. Sometimes hormones can be chemically identical to neurotransmitters . Both the nervous system and endocrine system make molecules to active receptors. The effects of the endocrine messages are slow, but outlast the effects of a neural message.